support.blackboxab.sesupport.blackboxab.se/manualer/m/md/md833a-r5.pdf1 fcc statement federal...

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© Copyright 1999. Black Box Corporation. All rights reserved.

1

FCC STATEMENT

FEDERAL COMMUNICATIONS COMMISSION

AND

INDUSTRY CANADA

RADIO FREQUENCY INTERFERENCE STATEMENTS

This equipment generates, uses, and can radiate radio frequency energyand if not installed and used properly, that is, in strict accordance with the manufacturer’s instructions, may cause interference to radiocommunication. It has been tested and found to comply with the limits for a Class A computing device in accordance with the specifications in Subpart J of Part 15 of FCC rules, which are designed to providereasonable protection against such interference when the equipment isoperated in a commercial environment. Operation of this equipment in aresidential area is likely to cause interference, in which case the user at hisown expense will be required to take whatever measures may be necessaryto correct the interference.

Changes or modifications not expressly approved by the party responsiblefor compliance could void the user’s authority to operate the equipment.

This digital apparatus does not exceed the Class A limits for radio noise emissionfrom digital apparatus set out in the Radio Interference Regulation of IndusrtyCanada.

Le présent appareil numérique n’émet pas de bruits radioélectriques dépassant leslimites applicables aux appareils numériques de classe A prescrites dans le Règlementsur le brouillage radioélectrique publié par Industrie Canada.

10

MODEM 32144

1. Specifications

Ringer Equivalence — 0.8 B

Environment — Ambient temperature:32 to 122° F (0 to 50° C); Storagetemperature: -4 to 158° F (-20 to 70° C);Relative humidity: 10 to 95%

Power — 90-132 VAC, 60 Hz

Size — 2.5"H x 10.1"W x 9.7"D (6.4 x 25.7 x24.6 cm)

Weight — 4 lb. (1.8 kg)

Standards — Bell 103, 212, 208, CCITTV.13, V.17, V.22, V.32, V.22 bis, V.25, V.32bis, V.33, V.29, V.32terbo

Protocol — Sync and async

Data Rate — Up to 16.8 and 19.2 Kbps

Operation — Full duplex over 2- or 4-wireleased lines or dialup lines

Connectors — (1) DB25 female, (5) RJ-45female, (1) 5-pin DIN

Configuration — AT Command set orfront-panel

Error Correction/Data Compression —MNP 1-5, V.42, V.42 bis

13

CHAPTER 2: Quick Start

2. Quick StartNote that if you ordered theModem 32144 Card, all you willreceive is the Card itself. It does notcome with the power transformeror cables listed below.

If you ordered the Modem32144, in addition to the modem,the shipping carton shouldcontain—

• A power transformer(with cable attached)

• A two-conductor crossover cable with an eight-pin modularconnector on one end and asix-pin modular connector onthe other end

• A four-conductor cable with twosix-pin modular connectors oneach end and spade lugs on theother end

Two cables are supplied with the modem, but both cables aren’talways needed, depending on theapplication. You will need an EIA RS-232 interface cable (notsupplied) to connect the modem tothe DTE (data terminal equipment,usually a computer). If the modemwill be operated in a manual dialmode, you will also need a standardtelephone set.

This instruction manual applies to the Modem 32144.

All information applies to boththe stand-alone and full-size rack-mount versions of the modem.Specialized low-profile rack-mountversions, designed for use in high-density rack enclosures, aredescribed in Appendix A.

QUICK SETUPS FOR A QUICKSTART

The simplest and fastest wayto set up the modem forimmediate use is to selectone of the factory-presetQuick Setup configurations.For most applications, onceyou have selected the properQuick Setup, the modem willbe ready for operation. Youwill not need to make furtheradjustments.Quick Setupsare explained fully beginningin Section 2.3 , followinginstallation instructions and abrief introduction to the frontpanel display and controls.

2.1 Installation2.1.1 UNPACKING

Keep the original shipping cartonin case you need to return themodem for any reason.

38

MODEM 32144

3. Options: Customizing the ModemSetup

• Summary Setup. This is thefastest way to selectively changemultiple options. All optionsare accessed using just a few of the LCD screens. However,because these screens shownumerical codes with very littleexplanation, Summary Setupis recommended only forexperienced users. SummarySetup is explained in AppendixB.

3.2 Front-Panel OptionsThis chapter describes the standardinstead of selecting options fromthe front panel. An alternatemethod for selecting options fromthe front panel (Summary Setup) is explained in Appendix B.

3.2.1 PUSHBUTTONS AND THE LCDOptions are selected from the frontpanel by pressing the front panelpushbuttons (Fig. 3-1). Thepossible choices for each optionare shown on the liquid-crystaldisplay (LCD).

3.1 Methods for Selecting OptionsThe modem allows you to easilyselect options in order to tailor the modem’s operation to suit aparticular application. Options can be selected in any of thefollowing ways:

• Quick Setup. This is the easiestway to set up the modem.Quick Setup (explained inChapter 2) automatically setsall options according to apreset configuration.

• Front-panel option selection.This is the easiest and mostcommonly used method forselecting individual optionchoices. Typically you wouldselect an overall configurationvia Quick Setup and thenmodify it to suit yourapplication by changingselected options from the frontpanel. Changes are made byaccessing individual optionscreens on the front panel LCDand then making selectionsusing the control pushbuttons.(An alternate way to changeoptions from the front panel isto use the modem’s SummarySetup feature, which isdescribed below.)

MODEM 32144

74

4. General Operation and SpecialFeatures

4.1 Quick ResetFor a reset of the modem, wherebyoption settings are not changed butthe modem is cleared for a newstart and the ROM memory chip ischecked, select RESET from MAINMENU screen 3. The modem willdisplay the power-on screen for afew seconds and then the EIAstatus screen. This feature enablesyou to reset the modem withoutpowering down the unit.

4.2 Storing Phone Numbers4.2.1 USES

The front panel PHONE screenallows you to store a single phonenumber to be used later for—

• Autodialing from the frontpanel or using the Hayes orV.25 bis mode autodialer

• DTR dialing

• Leased-line or dial-line auto-recovery.

This chapter describes thefollowing features and operationalmodes (listed here in the order inwhich they are presented):

• Quick reset

• Phone number storage

• Automatic fallback

• Dumb mode and Bell 208operation

• V.13 operation

• DTR dialing

• Dial Line Auto-Recovery

• Leased Line Auto-Recovery

• Security operation

• Modem-controlled remotecontrol

• Diagnostic interface control

The status screens, which displaydata concerning the operationalstatus of the modem, are discussedin Section 7.6 . Instructions forusing the pushbutton controls andLCD are included in Section 3.2.

97

CHAPTER 5: Hayes Emulation Mode

5. Hayes Emulation Modeto a preset configurationsuitable for typical Hayes modeapplications. To select the 2-wire dial Hayes Quick Setup,access QUICK SETUP screen 1on the LCD and presspushbutton 2.

• DIALER MODE. If you enabledthe Hayes mode autodialerusing the Dialer Mode option,no other options will bechanged. To enable theautodialer this way, selectDIALER from SETUP screen 2.Then select HAYES from theDIALER screen.

5.1.2 COMMAND GUIDELINES

The following guidelines for usingHayes-compatible AT commandsalso provide a summary of thefundamentals of Hayes modeautodialer operation.

NOTEAlthough carriage returnsare not shown in theexamples in this chapter, acarriage return is required atthe end of each commandline.

For easy reference, the followingtables appear consecutively at theend of this chapter:

• Hayes-Compatible Commands(Table 5-1)

• Hayes Mode Result Codes(Table 5-2)

• S Register Functions (Table 5-3)

5.1 Hayes Mode AutodialerWhen the Hayes emulation mode is enabled, the modem emulates aHayes autodialer and functionsmuch like a Hayes modem.Commands are issued from thecomputer keyboard (or otherDTE), and the modem iscompatible with software written to drive a Hayes-style “AT”command set.

5.1.1 ENABLING THE HAYES MODEAUTODIALER

The Hayes mode autodialer can beenabled in either of two ways—byusing the Quick Setup feature or byselecting HAYES from the DIALERscreen:

• QUICK SETUP. If you select 2-Wire Dial (Hayes) by using theQuick Setup feature, the Hayesmode autodialer will beenabled, and all modemoptions will be automatically set

127

CHAPTER 6: V.25 bis Autodialer

6. V.25 bis Autodialer

6.1.1 QUICK SETUP

Three Quick Setup configurationsare available for 2-wire dial V.25 bisoperation. Selecting any of thethree V.25 bis Quick Setups (viaQUICK on SETUP screen 1)enables the V.25 bis autodialer and causes all modem options tobe automatically set to a presetconfiguration. Each V.25 bis QuickSetup is suitable for a typical V.25bis application, depending on theDTE to be used.

To select a 2-wire dial V.25 bisQuick Setup, access QUICK SETUPscreen 2, 3, or 4 (for asynchronous;synchronous, character-oriented; or synchronous, bit-orientedoperation, respectively) on theLCD, and then press pushbutton 2.After selecting the desired V.25 bisQuick Setup configuration, you canreset individual options to suit yourapplication, if desired, as explainedin Chapter 3.

In accordance with the CCITTV.25 bis Recommendation, themodem V.25 bis asynchronousQuick Setup sets the characterlength to 10 bits, including 1 even parity bit. Both V.25 bissynchronous Quick Setups setthe modem for odd parity. (Forsynchronous operation, thecharacter-length option settinghas no effect.)

For international compatibility, the modem can be configured tofunction as a V.25 bis autodialer. In V.25 bis mode, the modem is compliant with CCITTRecommendation V.25 bis, aninternationally recognized standardfor serial automatic call originationand answering.

The V.25 bis autodialer uses thedialing command set defined bythe V.25 bis Recommendation. Itallows you to store and dial phonenumbers from the DTE in bothsynchronous and asynchronousapplications. You can dial numbersdirectly or you can instruct themodem to automatically dial apreviously stored number.

6.1 Enabling the V.25 bis AutodialerThe V.25bis autodialer can beenabled in either of two ways—byusing the Quick Setup feature or by selecting one of the Dialer Modeoptions.

138

MODEM 32144

7. Diagnostics

7.2 Symptoms and Scope of theProblemAs a first step toward isolating theproblem, carefully consider each of the following questions:

• When did the problem begin?

• What is malfunctioning? Try toisolate the component orcomponents of your system thatare malfunctioning.

• Has there been a recent changein the system?

• Has the modem beenreconfigured?

You can quickly find out if themodem has been reconfigured bychecking the checksum shown inthe SUMMARY screen (accessed viaSETUP screen 6) and comparing itwith the checksum displayed whenthe modem was operatingproperly—if you made a note ofthe previous checksum. If thechecksum is different from theoriginal checksum, one or moreoption settings have been changed.If you previously recorded thenumber strings (i.e., optionparameters) displayed in the setupscreens accessed via the SUMMARYscreen, you should be able todetermine which option settingshave been changed (by comparingthe previous and current optionparameters).

The troubleshooting informationin this chapter applies to allmodem applications (all dialupand leased-line modes), unlessspecifically stated otherwise.

For specific test procedures, turnto one of the following sections inthis chapter:

• Section 7.8, Local ModemDiagnostics

• Section 7.9, Remote Diagnostics

7.1 When and Why to Test If you are experiencingcommunications difficulties, theoverall objective in correcting theproblem should be to specificallyisolate the defective component inyour communications system. Thistypically involves three steps:Identifying the symptoms andscope of the problem, performinga physical inspection of all unitsand connections in the system and,finally, conducting diagnostic tests.Very often the diagnostic testingcapabilities of the modem can helpidentify the specific faultycomponent, whether it is themodem, the DTE or telephoneline.

5

MODEM 32144

Contents1. Specifications.............................................................................................102. Quick Start.................................................................................................13

2.1 Installation ........................................................................................132.1.1 Unpacking...............................................................................132.1.2 Connections ............................................................................142.1.3 Jumpers ...................................................................................15

2.2 Front-Panel LCD and Controls .......................................................162.2.1 Power-On Screen ....................................................................172.2.2 EIA Status Screen....................................................................17

2.3 Quick Setup ......................................................................................182.3.1 How to Select a Quick Setup .................................................18

2.4 Basic Operation................................................................................252.4.1 2-Wire Dial Hayes Mode (Quick Setup 1) ............................252.4.2 2-Wire Dial V.25 bis Mode (Quick Setup 2-4).......................262.4.3 2-Wire Dial Dumb Mode (Quick Setup 5)............................27

2.5 Leased Line (2- or 4-Wire) Mode (Quick Setup 6-9) ....................292.6 V.33 Leased Line Operation (Quick Setup 10) .............................292.7 2-Wire Dial Bell 208 Operation (Quick Setup 11-12)....................302.8 Two Types of Bell 208 Operation ....................................................31

2.8.1 Bell 208 Operation (Exclusive) .............................................312.8.2 V.32/208 Auto-Select Mode...................................................32

2.9 4-Wire Leased Line V.29 Mode (Quick Setup 13) .........................322.9.1 V.32 Dial Backup.....................................................................33

2.10 V.29 Fast Master and Slave Modes (Quick Setup 14-15) ..............332.11 If You Have Problems.....................................................................35

2.11.1 All Modes...............................................................................352.11.2 All Dial Modes (Hayes, V.25 bis, Dumb, Bell 208,

and V.32/208).......................................................................352.11.3 All Asynchronous Modes......................................................372.11.4 Hayes Mode...........................................................................372.11.5 All Leased-Line Modes (2-Wire, 4-Wire, V.33,

and V.29) ...............................................................................372.11.6 Leased Line (Excluding V.33 and V.29 Operation)...........37

3. Options: Customizing the Modem Setup...............................................383.1 Methods for Selecting Options .......................................................383.2 Front-Panel Options.........................................................................38

3.2.1 Pushbuttons and the LCD .....................................................38

156

MODEM 32144

Appendix A: Quick SetupConfigurations

Some options can be selected viaSummary Setup only. Theseoptions are not listed in Table A-1.The factory-default settings forthese options are shown inAppendix B.

Table A-1 shows the modemconfiguration—i.e., the defaultsetting for each option—for eachof the Quick Setup modes. Whenyou select a Quick Setup, themodem automatically sets alloptions as indicated in the table.The options are listed in the sameorder in which they appear on theLCD flow chart.

Instructions for selecting QuickSetups are included in Chapter 2.

166

MODEM 32144

Appendix B: Summary SetupIf you select AT, the AT

PROFILES screen will be displayed.When you select a Hayes modeconfiguration profile (user profile)from the AT PROFILES screen, theMODEM displays a setup screen forthe selected profile. The selectedprofile is used as the activeconfiguration and is alsodesignated as the default userprofile. Select 0 (pushbutton 1) to select profile 0; select 1(pushbutton 2) to select profile 1.Pushbutton 3, with the ATPROFILES screen displayed,enables you to select the defaultconfiguration profile: By pressingpushbutton 3, you can toggle(switch) between profile 0 orprofile 1 as the default—the effectis the same as issuing the &Ycommand (&Y0 or &Y1).

The SUMMARY screen includes a four-digit checksum value to theright of the word “SUMMARY.”This number will change if any ofthe option settings are changed, soit allows you to determine if any ofthe modem’s option settings havebeen changed, although youcannot determine from thisnumber which options have been changed. After setting up the MODEM, record this numberfor possible later reference.

Summary Setup is an advancedfeature designed to allow exper-ienced users to quickly changeoption settings for any mode. Mostoptions can be viewed from andchanged using a single LCD screen.Summary Setup is the fastest way toselectively change multiple options;however, because the SummarySetup screens show numericalcodes with very little explanation,this method of options selection isrecommended only forexperienced users.

Even though Summary Setupoffers these advantages, it is recom-mended only for experienced usersbecause there is very little guidanceon the LCD screen to indicatewhich option is being changed.

Changes made through SummarySetup modify the active modemconfiguration and are saved tomemory when you exit SummarySetup.

B.1 Summary Setup LCD ScreensSummary Setup (SUMMARY) isaccessed from screen 6 of theSETUP menu. From theSUMMARY screen, choose SETUPSto change options—but for Hayesmode operation (only), choose ATto change options for which thereare associated AT commands(Table B-1).

176

MODEM 32144

Appendix C: Connectors, Adapters,and Jumpers

• LEASED LINE—RJ-11 modularjack, for (6-pin) leased lineconnection

• PHONE—RJ-11 modular jack,for connection to a telephonehandset (optional)

These connectors are illustratedin Chapter 2, which explains howto install the modem and how tomake the connections referred toabove.

The modem includes an edgeconnector for optional rackmounting. When the modem israck mounted, the edge connectorperforms the functions of all theconnectors listed above (and theother connectors are not used).

C.1.1 CONNECTOR PIN ASSIGNMENTS

For users who need to knowconnector pin assignments, thisinformation is provided in FigureC-1 (DIAG, TX DIAL, RX DIAL,LEASED LINE, and PHONEconnectors) and in Table C-1(DTE interface connector).

This appendix provides a detaileddescription of al modemconnectors, including pinassignments. It also includes adescription of the modem jumperfunctions and a diagram that showsyou where to find the jumpers.

C.1 Connectors and AdaptersThe modem includes the followingconnectors (labeled on the rearpanel as indicated below):

• DTE—25-pin (DB25) RS-232/Dfemale cable connector, forconnection to DTE (computeror terminal)

• DIAG—RJ-45 modular jack(diagnostic connector), fordiagnostic port control(optional)

• POWER—Five-pin DINconnector for AC power

• TX DIAL—RJ-45 modular jackfor connection to a dial line

• RX DIAL—(Ignore “RX DIAL”label.) RJ-45 modular jack foralternate leased lineconnection (when an 8-pinconnector is required)

181

APPENDIX D: DC Voltage Models

Appendix D: DC Voltage ModelsD.1 IntroductionThe modems with codes MD833A-D12, MD833A-D24, and MD833A-D48are pre-configured for DC voltage operation. The MD833A-D12 is pre-configured for use with a -12 VDC power source, the MD833A-D24 is pre-configured for use with a -24 VDC power source, and the MD833A-D48 ispre-configured for use with a -48 VDC power source.

This addendum provides installation and jumper information for the DC pre-configured modems for applications where an external DC powersource will be used (i.e., not DC power provided from a rack enclosure). If the modem is to be installed in a rack, refer to the instruction manualsfor the modem and the rack.

CAUTIONThe -48 VDC model should be used only with an external DC powersource.

For modems using an external DC power source, the information in this addendum about installation and jumper settings supersedes theinformation in the rest of the Modem 32144 manual. However, all otherinformation in the instruction manual is applicable.

DSR during ALBON OFF

REMOTE TESTENABLE DISABLE

CD LEVEL LEASED-26 -33 -43

TEST OPTIONSDSR RMT

CTS to EIANORM RTS TRUE

CD to EIANORM TRUETOGGLE

DSR to EIANORM TRUE XOVER

EIACTS CD DSR

<1>

SETUPTEST EIA MODEM

<4>

EIADTR ALBT RDLT

<2>

DTR from EIANORMAL TRUE

RDL - DTE Ctrl'edENABLE DISABLE

ALB - DTE Ctrl'edENABLE DISABLE

TM to EIANORMAL TRUE

EIATM

<3>

CARRIER DET.LEASED DIAL

LVL

CD LEVEL DIAL-26 -33 -43

MODEM SETUPSCDLVL TXLVL

<1>

TRANSMIT LEVELLEASED DIAL

TX LEVELDEC INC

0 dBm

TX LEVEL (DL)PROG PERMIS

MODEM SETUPSSQ COMEQ TREL

<2>

TRELLIS CODEENABLE DISABLE

SIGNAL QUALITY10^3 10^5

MODEM SETUPSTXCLK T1 RETRN

<3>

TRANSMIT CLOCKINT RX-CLK EXT

AUTO-RETRAINENABLE DISABLE

T1 timer: 0.8secDEC INC

MODEM SETUPSANS/ORG ANSFREQ

<4>

ANSWER TONE2225Hz 2100Hz

ANS/ORG DEFAULTANSWER ORIGINATE

MODEM SETUPSFP SPK SPKVOL

<5>

SPEAKER VOLUMELOW MEDIUM HIGH

SPEAKER CONTROLOFF TILL-CD ON

FPENABLE DISABLE

MODEM SETUPSGUARD V13

<6>

V.13DEC INC

OFF

MODEM SETUPSCARR CTS RTS-CTS

<8>

PASSWORDCHANGE CLEAR

SETUPPHONE AUTO LCDI

<5>

301-555-1234DEC CTRL INC

LCD INTENSITY 5DEC INC

SETUPSUMMARY

<6>

PRI0011214E0 999 99

addr

AT PROFILES0 1 &Y0

DEC SKIP INC

CONFIRM

ATbefImqvwxy0102101341

AT&c

SETUPTYPE LINE SPEED

<1>

LINE TYPE2W-D 2W-LL 4W-LL

V42 CONTROLV42 SEL BUFFER

<1>

BUFFER SELECTENABLE DISABLE

V42 SELECTIONPROTOCOL V42bis

V42MODE CLASS BREAK

V42 MODEOFF MANDAT AUTO

LAPM/MNPDEC INC

SETUPV42 ADDR DIALER

<2>

V42 CONTROLDTE FLOW

<2>

V.42bisENABLE DISABLE

ADDRESS:DEC INC

999,999

PASSTHRU MODEENABLE DISABLE

SETUPANSWER DATA DISC

<3>

DISCONNECTRX TX

<1>

AUTO-ANSWERENABLE DISABLE

RX SPACE DISC'TENABLE DISABLE

TX SPACE DISC'TENABLE DISABLE

DATA FORMATTYPE LENGTH PAR

DATA FORMATSYNC ASYNC

DISCONNECTCARR. CURR. RTS

<2>

CURRENT DISC'TENABLE DISABLE

CARRIER DISC'TENABLE DISABLE

RATEDOWN UP

MAIN MENURESET RATE

<3>MAIN MENUSETUP TEST RMT

<2>MAIN MENUTALK QUICK DIAL

<1>

** **

SPEED TYPEDEC INC

V32

MIN RATE:DEC INC

0-300

MAX RATE:DEC INC

19,200

FLOW CONTROLDTE-DCE DCE-DTE

<1>

DTE SPEED:DEC INC

38,400

MNP CLASSDEC INC

5

FLOW CONTROLPASSTHRU

<2>

DCE-DTENONE CTSon/off

<1> DCE-DTEDC1/DC2 DC1/DC3

<2>

DTE-DCEDEC INC

RTS

RTS DISC'TDEC INC

OFF

PARITY:DEC INC

NONE

CHAR LENGTH9 1110

(Resetsmodem)

This screen is displayed onlyif V.32bis mode is selected.

* See reverse side of chart.

Setautomatically

in Hayesmode only.

Set automatically inHayes mode only.

Hayes mode only: Use S registerS10 to change these options.

These screens are only displayed on models that support theseoptions. MODEM SETUPS screens may be numbered differently.

These screens allow for quick option selections.(Use arrow pushbuttons to view full display.)For further explanation, see Instruction Manual,appendix C, Summary Setup.

Use INC (increase) and DEC (decrease) tocycle through digits (0-9); use CTRL to cyclethrough dialing control characters(T, *, #, etc.).

Checksum.If this numberchanges, atleast oneoption hasbeenchanged.

Continued below

Continuedfrom

BREAK:DEC INC

NDT/NEXP

COMPR EQUALDEC INC

T-III

GUARD TONE550Hz 1800HzOFF

PHONE CELL:DEC PROG INC

00

NO AUTO-RECOVERYDEC INC

RETURN:DEC INC

OFF

AUTO-RECOVERYSELECT RETN TEST

TEST EVERY 20minDEC INC

MODEM SETUPSPSWD

<7>TRAIN

CARRIERSWITCH CONSTANT

CTS DELAY: 0 msDEC INC

CTSRTS ON

TRAINING LENGTHLONG SHORT TER

V.32bis/14.4MV.32 V4.51/3.25

D TR MR RS CS9600 TM ER CD RD

TD LINE LEVELS. dBmTX=-09 RX=-24

ECHO: msec020 1.0

Hz CHANNEL FREQOFFSET: 1.0 Hz

THROUGHPUT15000 BPS

QUALITY 000 PKT: SIZE255 0233 00

ERTX MODEV42bis 38400

RATE

Power-on Screen

Software revision levels (may bedifferent than shown here.)

STATUS SCREENS

EIA status screen: Not all abbreviations will be presentat same time. (R in upper left corner indicates an incoming ring.)

Bar graph

Except for the power-on screen, the data shown on these screens will change,depending on external conditions and the modem's operational status.

DTE-DCEDEC INC

CTS

The Quick Setup screens are used to quickly select pre-set modem configurations for various applications.QUICK SETUP MENU

QUICK SETUP2-W DIAL (HAYES)

<1> QUICK SETUPV25 DIAL (Async)

<2> QUICK SETUPV25 DIAL (Syn_c)

<3> QUICK SETUPV25 DIAL (Syn_b)

<4> QUICK SETUP2-W DIAL (DUMB)

<5> QUICK SETUP2-W LEASED (ORG)

<6> QUICK SETUP2-W LEASED (ANS)

<7> QUICK SETUP4-W LEASED (ORG)

<8> QUICK SETUP4-W LEASED (ANS)

<9> QUICK SETUP4-WLL V.33

<10> QUICK SETUP2-W DIAL (208)

<11> QUICK SETUP2-W DIAL V32/208

<12> QUICK SETUP4-WLL V.29

<13> QUICK SETUPV.29 FAST MASTER

<14> QUICK SETUPV.29 FAST SLAVE

<15>

DIALERDEC INC

HAYESSPEED LIMITMAX MIN

SUMMARYSETUPS S-REG

314EAT

S-REGDEC INC

00:01

ATbefImqvwxy0102101341

AT&c

Pushing 3changesfrom &Y0to &Y1

Appendix E: LCD Flow Chart

DCE-DTE

REMOTECONTROL TEST

<1>

CHECKSUMMAIN PUMP

MAIN MENURESET RATE

<3>MAIN MENUSETUP TEST RMT

<2>MAIN MENUTALK QUICK DIAL

<1>

V.32bis/14.4MV.32 V4.51/3.25

D TR MR RS CS9600 TM ER CD RD

TD LINE LEVELS. dBmTX=-09 RX=-24

ECHO: msec020 1.0

Hz CHANNEL FREQOFFSET: 1.0 Hz

THROUGHPUT15000 BPS

QUALITY 000 PKT: SIZE255 0233 00

ERTX MODEV42bis 38400

RATE

* **

Power-on Screen

Software revisionlevels (may bedifferent thanshown here.)

STATUS SCREENS

Bar graph

(Resets modem. LCDreturns to power-on screen,then EIA status screen.)

This screen appears only in theevent of a dial failure. Specificmessage appears on bottom line.

MANUAL-DIALTALK DATA

Displayed only on theALX V.32M and ALXV.32/14.4M.

REMOTE TESTRDL RDLST

REMOT DIGIT LOOPON OFF

RDL SELFTESTON OFF

REMOTECTRL ADDR/C ADDR

<2>

LOCAL TESTALB ALBST ST/E

<1>

ANALOG LOOPBACKON OFF

ANALOG SELFTESTON OFF

SELFTEST w/ERRORON OFF

LOCAL TESTDLB ALBX ALXST

<2>

DIGITAL LOOPBACKON OFF

ANALOG LOOP (EXT)ON OFF

ANALOG ST (EXT)ON OFF

If SLOT/C is selectedfrom REMOTE screen2 (above), the top linehere will read SLOTNUMBER: 01.

Data displayed here is for use by servicing personnel.Screens show software revision levels and variouschecksums for both the main processor and the datapump (transmitter, T, and receiver, R). It is unlikely thatthe numbers on your unit will match those shownhere—this is normal.

(Accessed by pressing 1from EIA status screen.)

Note: When a test is activated, the EIA status screen will be displayed.

Use pushbutton 2 to togglebetween ADDR/C and SLOT/C.

MAINV3.02.02

m1_mt9bf219BB

PumpV2.03.1 U52 280C

U51 C5E8

DIAL FAILURENO DTR

DIAL CELL:DEC DIAL INC

e00

ADDRESS :DEC INC

999,999

AUTO-DIALDIAL HANGUPCELL

Displayed on the Modem 32144.

182

MODEM 32144

D.2 InstallationUse the supplied cable to attachthe modem to the external DCpower source, as shown in Fig. D-1.

Fig. D-1. Attaching the supplied cable to the DC power source.

DIAGTX

DIALLEASED

LINE PHONEPOWER

Black

Red

Pos. (+)source

Neg. (-)source

Refer also to Section 2.1,Installation but ignore informationabout the AC power transformercable.

183

APPENDIX D: DC Voltage Models

D.3 Jumper SettingsThe power jumpers have been pre-set at the factory for DC voltageoperation as shown in Tables D-1.

Table D-1. Jumper Settings for -12/-24/-48 VDC Operation

Jumper(s) Setting

JP2 Pins 2 and 3 connected

JP3, JP4 Pins 1 and 2 connected

(set to same position)

For other jumper settings, referto the rest of this manual. (But forthe DC modems, ignore theinformation in the manuals forjumpers JP2, JP3, and JP4.)

184

MODEM 32144

D.4 Jumper LocationsThe jumper locations are shownbelow for your information;however, since the jumper settingsare pre-configured, you should nothave to change them.

Fig. D-2. Partial view of modem circuit board, showing jumperlocations.

JP2

JP1

JP6JP5

JP8

JP7

JP3

JP4

For each jumper, pin 1 isidentified by a “1” on the modemcircuit board. (The JP2 pin 1 labelmay be difficult to read; JP2 pin 1 is the pin closest to the edgeconnector.)

177

APPENDIX C: Connectors, Adapters, and Jumpers

Figure C-1. Connector Pin Assignments.

All connectors are shown as viewed from the back of the modem. Pins not included in the listings above are not used.

POWERDIAG PHONE

LEASEDLINE

RXDIAL

TXDIALDTE

REAR PANEL

DB25

RJ-45

1 2 3 4 5 6 7 8

Dial Line Connector

Pin345678

FunctionA/MIRingTipA1/MICPCPR

RJ-11

1 2 3 4 5 6

Phone Connector

Pin2345

FunctionARingTipA1

RJ-11

1 2 3 4 5 6

Leased LineConnector

Pin2345

FunctionRXLLTXLLTXLLRXLL

RJ-45

1 2 3 4 5 6 7 8

Pin1278

FunctionTXLLTXLLRXLLRXLL

Alternate LeasedLine Connector

(Ignore “RX DIAL” Label)

Diagnostic Connector

Pin Function1 Constellation Y Output2 Constellation X Output4 Ground (for transmit and

receive data and constellation)5 Receive Data (output from

modem)6 Transmit Data (input to modem)

RJ-45

1 2 3 4 5 6 7 8

DIAG port always appears to asystem as a DCE port.

178

MODEM 32144

Table C-1. Pin Assignments—DB25 TIA/EIA Interface Connector

Pin Function Designation SourceEIA ITU-T LCD

1 Frame ground—not connected AA 101

2 Transmit (send) data (TD) BA 103 TD DTE

3 Received data (RD) BB 104 RD Modem

4 Request to send (RTS) CA 105 RS DTE

5 Clear to Send (CTS) CB 106 CS Modem

6 Data Set (modem) Ready (DSR) CC 107 MR Modem

7 Signal ground (SG) AB 102 Ground

8 Carrier detect (CD) CF 109 CD Modem

9 Testing voltage, +10V +P Modem

10 Testing voltage, -10V -P Modem

15 Transmit clock (TC) DB 114 Modem

17 Receive clock (RC) DD 115 Modem

18 Analog loopback (ALB) control1 CN DTE

20 Data terminal ready (DTR) CD 108/2 TR DTE

21 Remote digital loopback (RDL) CN DTEcontrol1

22 Ring indicator (RI) CE 125 R Modem

24 External transmit clock (XTC) DA 113 DTE

25 Test mode indicator (TM)2 CN TM Modem

1+ voltage activates indicated loopback test (but only if ALB-DTE Ctrl’ed or RDL-DTE Ctrl’ed option is enabled);—voltage disables test.2Alternately, pin 25 may be used for analog loopback (ALB) control.

179

APPENDIX C: Connectors, Adapters, and Jumpers

C.2 Jumpers

WARNINGJumpers should be switchedonly by qualified servicepersonnel.

For most applications, there is noneed to reset the modem’s internaljumper switches. However, ajumper switch will have to be resetif you need to—

Connect frame ground to signalground, Switch from A/A1 controlto MI/MIC control, Strap themodem for use in a DC rackenclosure, or Change the functionof EIA interface pin 25.

If you need to reset a jumperswitch, refer to the following pageto determine the jumper thatshould be switched, where it islocated, and how it should be set.The jumpers are numbered on thecircuit board; for example, JP4 isjumper 4. To access the jumpers,unscrew the four screws on thebottom of the modem and carefullylift off the cover.

WARNINGImproper setting of AC andDC power jumpers couldresult in serious damage tothe modem.

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MODEM 32144

Table C-2. Jumper Switch Functions

Jumper(s) Position1 Function

JP1 FG Frame and signal ground connected

Alternate position Not connected

(no legend)

JP2, JP3 A1 A/A1 control

(Set to same MI MI/MIC control

position)

JP4, JP5, AC AC power

JP8 Alternate position DC power (for Telco 48 VDC battery)

(Set to same

position)

JP7 TM (output) Pin 25 used as test mode indicator

AL (input) Pin 25 used for analog loopback

1As indicated by legend printed on modem circuit board.

Factory settings are shown in boldface.

167

APPENDIX B: Summary Setup

B.2 Changing Options via SummarySetupThe appearance of the three setupscreens selected via SETUPS andAT (profile 0 or 1) is essentially the same: Brief descriptiveinformation on the top line and a long string of numbers on thebottom line. The numbers arebroken down into groups, witheach group representing a categoryof options (dial line options, EIAinterface options, etc.).

Each digit position represents anoption, and the number in eachdigit position indicates the currentoption setting (parameter). Tochange an option setting, use thefront panel pushbuttons to changethe parameter (number), asexplained in the following section.

The diagrams on the followingpages show—

• Which options are included ineach option group

• Which option is indicated byeach digit position within thegroup

• The possible parameters foreach option

B.2.1 SUMMARY SETUP PUSHBUTTONFUNCTIONS

The three Summary Setup screensare different from all other modemscreens in that you can scroll acrossthe string of numbers; also, thepushbutton functions are different. For the three Summary Setupscreens only, the modempushbuttons function as follows:

• Pushbutton 1 moves the cursorto the left. Pushbutton 3 movesthe cursor to the right. If thecursor is at the end of thescreen, the screen will scrollone character at a time.

• Pushbutton 2 increments theblinking value (i.e., theparameter, or current optionsetting). The value will cyclethrough the highest possibleparameter value and then backto 0 or 1.

• The right arrow button movesthe screen to the beginning ofthe next group of options tothe right. The left arrow buttonmoves the screen to thebeginning of the next group ofoptions to the left. Groups ofoptions are separated by blankspaces on the LCD.

000

MODEM 32144

NOTEOn the Summary Setupscreens that show ATprofiles 0 and 1, the cursorlocation is indicated by asolid black box when thecursor is positioned in ablank cell (one with nocharacters).

B.2.2 EXPLANATION OF SUMMARYSETUP SCREENS

Note that options are identified onthe Summary Setup screens only bythe relative positions of thenumbers within the number string,as indicated in the followingdiagrams. Each digit positionrepresents an option, and thenumber in each digit positionindicates the current option setting(parameter).

The string of numbers in eachdiagram shows the factory defaultsetting for each option (i.e., theHayes mode default settings). Eachdiagram also identifies all possiblesettings for each option.

NOTENumbers that are notidentified in the followingdiagrams represent optionsettings that are reservedfor future use or factory use.These settings should notbe changed.

168

169


Fig. B-1. Primary Options.

Speed type: 0=Auto (V.32/208), 1=V.33, 2=V.32/32bis, 3=Bell 208Speed limit, min. (bps): 0=9600, 1=4800, 2=2400,3=1200 4=600, 5=0-300,6=1200/75,7=14,400, 8=12,000, 9=7200Speed limit, max. (bps): 0=9600,1=4800,2=2400,3=12000,4=600, 5=0-300, 6=EIA-23, 7=1200/75, 8=14,400,9=12,000,A=7200Buffer mode/speed conversion: 0=enable, 1=disableV.42 mode : 0=off, 1=mandatory, 2=automaticDialer mode: 0=off, 1=Hayes, 2=DTR dialing; 3=V.25bis, async; 4=V.25bis, sync, character-oriented; 5=V.25bis, sync, bit-oriented; 6=Penril mode

Character length (bits): 0=8, 1=9, 2=10, 3=11Data format: 0=sync, 1=async

258021210PRI

Line type: 0=2--wire dial, 1=2-wire leased, 2=4-wire leased

NOTES: Speed limit, min., and speed limit, max.: 7200 bps parametersare available only if V.32bis mode is enabled.ALX V.32 and ALX V.32M only: Available speed limit selections: Max., 0-7 and A;min., 0=6 and 9. Default max. speed limit setting: 0 (9600 bps).Speed type: Settings 0, 1 and 3 are not available on all all ALX models.

LCD

170

MODEM 32144

Fig. B-2. Address.

9 9 9

Groupaddress

9 9 9

Unitaddress

a d d r

dial0 0 0 0 0 0 1 0 2 1 0

Pulse dialing rate (pulse per sec): 0=10, 1=20Wait for carrier (sec): 0=30, 1=45, 2=60, 3=75T1 timer (sec): 0=0, 1=0.3, 2=0.8, 3=1.6, 4=3.Carrier detect level, dial (dBm): 0= -51, 1= -41, 2= -34TX level, dial: 0=programmable, 1=permissiveDisconnect, RTS (sec): 0=off, 1=20, 2=40 . . .7=140Disconnect, line current: 0=enable, 1=disableDisconnect, carrier: 0=enable, 1=disableDisconnect, TX space: 0=enable, 1=disableDisconnect, RX space: 0=enable, 1=disableAuto-answer: 0=enable, 1=disable

Fig. B-3. Dial Line Options.

171


Fig. B-4. EIA Interface Options.

Fig. B-5. V.42 Error Correction Options.

eia0 1 0 1 1 1 0 0 0

CD and DSR delay: 0=disable, 1=enableTest mode: 0=normal, 1=trueRemote digital loopback test: 0=enable, 1=disableAnalog loopback test: 0=enable, 1=disableCTS: 0=normal, 1=follow RTS, 2=true, 3=onCarrier detect: 0=normal, 1=true, 2=toggleDSR: 0=normal, 1=true, 2=crossoverDTR: 0=normal, 1=true

MNP class (limit): 1=class 1, 2=class 2, 3=class 3, 4=class 4, 5=class 5Flow control, DCE to DTE: 0=none, 1=CTS, 2=DC1/DC2, 3=DC1/DC3Flow control, DTE to DCE: 0=none, 1=RTS, 2=DC1/DC2, 3=DC1/DC3Parity: 0=none, 1=odd.2=even, 3=mark, 4=space

DTE pass-through flow control: 0=enable, 1=disableFlyback buffer: 0=enable, 1=disable

V.42bis: 0=enable, 1=disableV.42 protocol: 0=LAPM only, 1=MNP only, 2=LAPM/MNP

Link flow control: 0=disable, 1-enable, 2=slavedDCE pass-through flow control: 0=disable, 1=enableSelective retransmission: 0=disable, 1=enable

DTE speed (bps): 0=38,400, 1=19,000, 2=9600, 3=4800, 4=2400, 5=1200, 6=600, 7=300, 8=110

Break handling: 0=none, 1=destr./expedited, 2=non-destr./expedited, 3=non-destr./non-expedited

"V.42 <1>" and "V.42 <2>" are displayedto help indicate the relative position ofindividual options across the LCD.

2 0 0 0 0 1 0 2 10 0 3 3 5 3 1 1V.42 <1> V.42 <1>

172

MODEM 32144

Fig. B-6. Leased Line Options.

Carrier detect level, leased (dBm): 0= -43, 1= -33, 2=-26TX level, leased (dBm): 0=0, 1= -1... 9= -9, A= -10 ... F= -15TX clocking: 0=internal, 1=received clocking, 2=externalAnswer/originate: 0=answer, 1=originate

Auto-recovery test interval (min): 0=10, 2=40, 3=60Auto-recovery return (sec): 0=off, 1=10, 2=40, 3=60, 4=120Auto-recovery select: 0=none, 1=dial if bad 1 min ... 4=dial if bad 4 min, 5=dial if bad 30 sec 96-8 not used), 9=manual recovery

L. L.1 0 0 2 0 0 1 0

173


Fig. B-7. Data Pump 1 Options.

Trellis coding: 0=enable, 1=disableAnswer tone: 0=2225 Hz, 1=2100 HzGuard tone: 0=550 Hz, 1=1800 Hz, 2=offAuto-retrain: 0=enable, 1=disableSignal quality level (error/bits): 0=1 in 10^3, 1=1 in 10^5Compromise equalizer type: 0=I, 1=II< 2=III, 3=IV, 4=off

Phase reversal in answer tone: 0=enable, 1=disableAuxiliary channel: 0=enable, 1=disableSpeed fallback: 0=enable, 1=disable

"pump1," "pump2," and "pump3" are displayed to help indicatethe relative positions of individual options across the LCD.The "pump2", and "pump3" options are identified below.pump 1

2 0 0 2 1 0 3 0 0 0 1

12

34

56 Rate renegotiation (RRP): 0=disable, 1=enable

89

10

12

34

56

78

pump 20 0 0 0 0 1 1 0 0 0

pump 30 0 0 0 0 1 0 0

Turnaround delay: 0=disable, 1=enableSatellite delay: 0=disable, 1=enableRTS-to-CTS delay (ms): 0=none, 1=15, 2=50, 3=150CTS: 0=always ON, 1=follow RTSCarrier type: 0=switched, 1=constant

Forward rate renegotiation: 0=disable, 1=enableRetrain threshold (error/bits): 0=10^4, 1=10^6208 phase detection: 0=normal, 1=compensated

V.26 scrambler: 0=disable, 1=enableAnti-streaming timer: 0=disable, 1=enableV.26 dibit encoding: 0=alternative A, 1=alt. BEcho protection tone: 0=disable, 1=short, 2=long

V.27bis 2400-bps alternatives: 0=alternative i, 1=alt. iiV.3x/208 auto-detect mode: 0=disable, 1=enableV.22bis S1 duration (ms): 0=100, 1=150Fast connect 103 mode: 0=disable, 1=enable

Fig. B-8. Data Pump 2 and 3 Options.

174

MODEM 32144

Fig. B-9. Miscellaneous Options.

Op. mode fallback: 0=Bell 212A and 103, 1=V.22/V.21/V.23Remote test: 0=enable, 1=disableDSR during ALB: 0=enable, 1=disableFP: 0=enable, 1=disableLCD intensity: 0, 1... 7 (7=greatest intensity)Speaker volume: 0=low, 1=medium, 2=highSpeaker control: 0=on, 1=on till CD, 2=off

misc 1

"misc1," "misc2," and "misc3" are displayed to help indicatethe relative positions of individual options across the LCD.The "misc2", and "misc3" options are identified below.1 2 3 0 0 0 0

Low-profile DIAG LED: 0=Connect status, 1=DTR statusCFI AB response on disconnect: 0=disable, 1=enable

Multimode handshake: 0=T1 timer, 1=V.32bis Annex A

misc 2 misc 30 1 0 0 0 0 0 F F F F 1 0 0 0 0 0 0 0 0

Wait for MNP link request (sec): 0=3, 1=7Leased line interrupt:0=off, 1=onRemote RTS signaling: 0=off, 1=on

Answer tone detection: 0=enable, 1=disableAnswer tone detection: 0=enable, 1=disable

V.13 operation: 0=off, 1=TX only, 2=RX only, 3=TX and RXDTE=DCE speed: 0=disable, 1=enablePenn/V.25bis DTR dialing: 0=enable, 1=disable

175


Fig. B-10. Hayes Mode Options—For Each AT Profile.

AT commands

AT & commands

S registers

AT/ commands(most are forV.42 options)

ATbeflmqvxy110210141

AT&cdgjlpqrsx1200000000

s00 s18 s25 s26001 000 005

AT/abcdfkmnpq t vx315013032330011

Flow control, DCE

Flow control, DTE

Load inactivity timer

157

APPENDIX A: Quick Setup Configurations

Table A-1. Quick Setup Configurations

158

MODEM 32144

Table A-1. Quick Setup Configurations (continued)

159



160

MODEM 32144


161


Table A-2. Additional Quick Setup Configurations

Default settings listed by Quick Setup mode

Option Bell 4-wire V.29 V.292081 leased fast fast

V.29 master slaveCommunication Standard option

STD 208 V.29 V.29 V.29

Speed Limit option, V.32, V.32M, V.32/14.4, V.32/14.4M, V.32/19.2, V.32/19.2M

MAX DCE 4800 9600 9600 9600RATE

MIN DCE 4800 4800 4800 4800


Option Bell 2081 4-wire V.29 fast V.29 fastleased V.29 master slave

BUFFER Disable Disable Disable Disable

DTE SPEED 38.4 Kbps 38.4 Kbps 38.4 Kbps 38.4 Kbps

FLOW RTS RTS RTS RTSCONTROLDTE-DCE

FLOW CTS CTS CTS CTSCONTROLDCE-DTE

DTE Disable Disable Disable DisablePASS-THRUFLOW CTRL

162

MODEM 32144

Table A-2 (continued). Additional Quick Setup Configurations

(Miscellaneous)

ADDRESS2 999,999 999,999 999,999 999,999

DIALER OFF OFF OFF OFFMODE

AUTO Enable Enable Disable DisableANSWER

Data Format Options

DATA TYPE Sync Sync Sync Sync

CHAR 10 10 10 10LENGTH

PARITY None None None None

Disconnect Options

RX SPACE Disable Disable Disable DisableDISC’T

TX SPACE Disable Disable Disable DisableDISC’T

CARRIER Enable Enable Enable EnableDISC’T

LINE CURR Enable Enable Enable EnableDISC’T

RTS DISC’T OFF OFF OFF OFF

2Quick Setup does not change the address to the default address, but a factoryreset does.

163



Test Options

DSR ON ON ON ONDURINGALB

REMOTE Enable Enable Enable EnableTEST

EIA Options

CTS to EIA Normal Normal Normal Normal

CD to EIA Normal Normal Normal Normal

DSR to EIA Normal True True True

DTR from EIA Normal True True True

ALBT DTE Disable Disable Disable DisableCTRL’ED

RDL DTE Disable Disable Disable DisableCTRL’ED

TM to EIA True True True True

Modem Setup Options

CD LEVEL, -26 dBm -26 dBm -26 dBm -26 dBmLEASED

CD LEVEL, -43 dBm -43 dBm -43 dBm -43 dBmDIAL

TX LEVEL, 0 dBm 0 dBm 0 dBm 0 dBmLEASED

TX LEVEL, Permis. Permis. Permis. Permis.DIAL

SIGNAL 104 104 10$ 104

QUAL LEVEL

164

MODEM 32144


COMPR T-III T-III T-III T-IIIEQUAL

TRELLIS Enable Enable Enable EnableCODE

TRANSMIT Internal Internal Internal InternalCLOCKING

T1 TIMER 0.8 sec 0.8 sec 0.8 sec 0.8 sec


AUTO- Enable Enable Disable DisableRETRAIN

ANS/ORG ORIG ORIG ORIG ANSDEFAULT

ANS TONE 2100 Hz 2100 Hz 2100 Hz 2100 Hz

FRONT Enable Enable Enable EnablePANEL

SPKR CTRL Til-CD Til-CD Til-CD Til-CD

SPKR VOL Medium Medium Medium Medium

GUARD OFF OFF OFF OFFTONES

V.8 PROC Enable Enable Enable Enable

V.13 OFF OFF OFF OFFOPERATION

TRAINING Long Long Short ShortLENGTH

CARRIER Switched Constant Constant Switched

CTS RTS RTS RTS RTS

RTS-CTS DLY 150 ms 0 0 0

165



Auto-Recovery Options

AUTO-RECV None None None NoneSELECT

AUTO-RECV OFF OFF OFF OFFRETURN

AUTO-RECV 20 min 20 min 20 min 20 minTEST INT’VL

AUTO-RECV INTER INTER INTER INTERTEST TYPE

LCD Intensity Option

LCD 5 5 5 5INTENSITY

166

MODEM 32144

Do not Make PDF of this page

6

MODEM 32144

3.3 Selecting Options from the Front Panel ........................................403.3.1 DEC/INC (Decrease/Increase) Screens ..............................413.3.2 Example of How to Select an Option ...................................423.3.3 How to Return to the EIA Status Screen ..............................433.3.4 Automatic Configuration Save Feature.................................433.3.5 How to Return to Default Settings ........................................43

3.4 Options..............................................................................................443.5 Speed (Data Rate) Options .............................................................443.6 V.42 Error Correction Options........................................................483.7 Address..............................................................................................543.8 Dialer Mode ......................................................................................553.9 Auto-Answer Option ........................................................................553.10 Data Format Options .....................................................................563.11 Disconnect Options........................................................................573.12 Test Options.....................................................................................583.13 EIA Options .....................................................................................583.14 Modem Setups................................................................................603.15 V.33 and Bell 208A/B Options......................................................653.16 Options Accessible Only via Summary Setup...............................67

3.16.1 Dial Line Options .................................................................673.16.2 V.42 Error-Correction Options ............................................673.16.3 Data Pump Options..............................................................693.16.4 Miscellaneous Options .........................................................70

4.0 General Operation and Special Features ..............................................744.1 Quick Reset.......................................................................................744.2 Storing Phone Numbers ..................................................................74

4.2.1 Uses..........................................................................................744.2.2 How to Store a Phone Number .............................................75

4.3 Automatic Fallback...........................................................................774.3.1 Operating-Mode Fallback ......................................................774.3.2 Automatic Rate Adjustment...................................................79

4.4 Dumb Mode and Bell 208 Operation.............................................804.4.1 Manual Originate/Answer Operation ..................................80

4.5 V.32/208 Auto-Detect Mode............................................................814.5.1 V.32/V.32 bis Operation.........................................................814.5.2 Bell 208 Operation .................................................................824.5.3 Automatic Fallback.................................................................82

4.6 V.13 Operation .................................................................................824.7 DTR Dialing......................................................................................82

4.7.1 Dialing a Stored Number.......................................................834.7.2 Answer Mode Operation........................................................83

7

MODEM 32144

4.8 Dial Line Auto-Recovery ..................................................................834.8.1 Setting Up the Modem for Dial Line Auto-

Recovery ..................................................................................834.8.2 Recovery Procedure ...............................................................84

4.9 Leased Line Auto-Recovery .............................................................844.9.1 Autodial Backup .....................................................................854.9.2 Exit from Leased Line Auto-Recovery ..................................854.9.3 Leased-Line Auto-Recovery Options.....................................86

4.10 Modem Security Operation...........................................................874.11 Automatic Password Protection (APP)..........................................874.12 Configuring Modems for APP.......................................................89

4.12.1 APP Without Callback ..........................................................894.12.2 APP With Callback................................................................894.12.3 Password Screens ..................................................................894.12.4 Valid Password Characters ...................................................904.12.5 APP with Callback: Storing the Password with

Callback Number..................................................................914.13 Disabling APP .................................................................................91

4.13.1 Temporarily Disabling APP..................................................914.13.2 Clearing the Password ..........................................................92

4.14 Manual-Response Password Protection (MPP)............................924.15 Commands for Enabling MPP.......................................................934.16 How to Use Password Commands.................................................94

5. Hayes Emulation Mode ............................................................................975.1 Hayes Mode Autodialer ...................................................................97

5.1.1 Enabling the Hayes Mode Autodialer...................................975.1.2 Command Guidelines ............................................................97

5.2 Result Codes .....................................................................................995.3 Transmission Speed........................................................................1005.4 Hayes Compatible Commands......................................................1015.5 S Registers .......................................................................................107

5.5.1 Reading and Setting Registers .............................................1075.5.2 S Register Functions .............................................................108

5.6 Saving Option Selections ...............................................................1105.7 Facsimile (Fax) Transmission........................................................1115.8 Hayes Mode Reference Tables ......................................................111

6. V.25bis Autodialer ...................................................................................1276.1 Enabling the V.25bis Autodialer....................................................127

6.1.1 Quick Setup ..........................................................................1276.1.2 2=Dialer Mode (DIAL V.25 bis Screen) ..............................1286.1.3 DTR Dialing in V.25 bis Mode .............................................128

6.2 V.25 bis Autodialer Commands .....................................................1286.3 Dialing Parameters.........................................................................1326.4 V.25 bis Result Codes .....................................................................134

8

MODEM 32144

6.5 Message Format..............................................................................1366.5.1 Asynchronous........................................................................1366.5.2 Synchronous, Character-Oriented ......................................1366.5.3 Synchronous, Bit-Oriented ..................................................137

7. Diagnostics...............................................................................................1387.1 When and Why to Test ...................................................................1387.2 Symptoms and Scope of the Problem...........................................1387.3 Physical Inspection.........................................................................1397.4 Overview of Modem Diagnostics...................................................1397.5 How to Select and Activate Tests ...................................................140

7.5.1 Front-Panel Control .............................................................1407.5.2 Running Tests in Hayes Mode .............................................1407.5.3 Remote Test Control ............................................................140

7.6 Diagnostic Monitoring: Status Screens........................................1407.6.1 EIA Status Screen .................................................................1407.6.2 Other Status Screens ............................................................141

7.7 Rate Change Screen.......................................................................1437.8 Local Modem Diagnostics .............................................................144

7.8.1 Analog Loopback (ALB) Test..............................................1447.8.2 Analog Loopback Self-Test (ALBST) ..................................1457.8.3 Analog Loopback Self-Test with Errors (ST/E) .................1477.8.4 External Analog Loopback (ALBX) Test............................1477.8.5 External Analog Loopback Self-Test (ALXST) ..................1497.8.6 Digital Loopback Test (DLB) ..............................................151

7.9 Remote Modem Diagnostics..........................................................1537.9.1 Remote Digital Loopback (RDL) Test ................................1537.9.2 Remote Digital Loopback Self-Test (RDLST) ....................154

Appendix A: Quick Setup Configurations ................................................156Appendix B: Summary Setup.....................................................................166

B.1 Summary Setup LCD Screens .......................................................166B.2 Changing Options via Summary Setup ........................................167

B.2.1 Summary Setup Pushbutton Functions..............................167B.2.2 Explanation of Summary Setup Screens ............................168

Appendix C: Connectors, Adapters, and Jumpers ...................................176C.1 Connectors and Adapters .............................................................177

C.1.1 Connector Pin Assignments................................................178C.2 Jumpers...........................................................................................179

9

MODEM 32144

Appendix D: DC Voltage Models ...............................................................181D.1 Introduction...................................................................................181D.2 Installation .....................................................................................182D.3 Jumper Settings .............................................................................183D.4 Jumper Locations ..........................................................................184

Appendix E: LCD Flow Chart ....................................................................185

139

CHAPTER 7: Diagnostics

7.3 Physical InspectionThe next step in isolating adefective component is to inspectthe system. If you have been able totrace the problem to a specific site,examine that site. Check theinstallation of the modem andDTE. Are all cables in goodcondition and fully connected?Are all components in the systemreceiving power? Inspect thesystem as thoroughly as possible.

7.4 Overview of Modem DiagnosticsOnce you have identified thesymptoms and conducted aphysical inspection of the sites inquestion, you can use diagnosticmonitoring and testing to furtherisolate the problem. The modem isequipped with diagnosticcapabilities that will often enablethe user to locate faults quickly andeasily. The diagnostic features ofthe modem fall into twocategories—local and remote—as listed below.

There are six types of localmodem diagnostics:

• Analog loopback (ALB)

• Analog loopback self test(ALBST)

• Analog loopback self test witherrors (ST/E)

• External analog loopback(ALBX)

• External analog loopback selftest (ALXST)

• Digital loopback (DLB)

There are two types of remotediagnostics:

• Remote digital loopback (RDL)

• Remote digital loopback selftest (RDLST)

The sequence in whichdiagnostic tests should beconducted depends upon thesymptoms that have been identifiedas well as the availability ofpersonnel at the remote site andexternal test equipment. The selftest pattern generator and patterndetector built into the modemalleviates the requirement forexternal test equipment. With thenon-self tests, either a standardDTE or an external bit error ratetest (BERT) is used to generate testdata and compare it with receiveddata.

Because more transmissionerrors occur at higher speeds onmarginal transmission facilities,begin testing at 14.4 Kbps. If errorsoccur, reduce the speed and tryagain. If you cannot correct theproblem, contact TechnicalSupport for assistance.

140

MODEM 32144

7.5 How to Select and Activate Tests7.5.1 FRONT-PANEL CONTROL

Tests are accessed and activated inthe same way options are selected:by using the LCD and front-panelpushbuttons (as explained inChapter 3). To find the LCD screenfor a specific test, refer to the LCDflow chart (DIAGNOSTIC ANDCONTROL FUNCTIONS)included with this manual. Onceyou have accessed the screen for aspecific test, press pushbutton 1 tobegin the test (select ON). A teststatus screen will then beautomatically displayed. Todeactivate a test, press the ENTpushbutton and then pushbutton3. (The ENT button cannot beused to exit the text screen untilthe test has been deactivated.)

NOTEFor valid test results, errorcorrection must be disabledbefore diagnostic tests arerun. To disable errorcorrection, set the V.42Mode option to OFF.

7.5.2 RUNNING TESTS IN HAYES MODE

In Hayes emulation mode only,most of the diagnostic testsavailable on the modem can beactivated via the DTE keyboard byusing the &T commands listed inSection 5.4. The duration of a testcan be set by assigning a value toregister S18. For example, ATS18=30 sets the test time to 30seconds. The command &TOterminates a test. For furtherinformation, see Section 5.4.

7.5.3 REMOTE TEST CONTROL

You can configure the modem toignore or accept requests fromremote modems to initiate tests onyour modem. To access the remotetest control option, select TESTfrom SETUP screen 4. Then selectRMT from the TEST OPTIONSscreen. From the REMOTE TESTscreen, select ENABLE to allowremote test initiation or DISABLEto refuse remote test requests.

7.6 Diagnostic Monitoring: StatusScreens To obtain additional informationabout the status of thecommunications system, observethe status screen described in thefollowing sections. To view thesescreens, push the ENT button untilthe EIA status screen appears. Usethe right arrow pushbutton toadvance to other status screens.

7.6.1 EIA STATUS SCREEN

The EIA status screen indicates theoperational status of the modem aswell as the condition of certain EIARS-232 leads. The abbreviationsthat may appear are identifiedbelow; however, typically, only a fewof these abbreviations will bedisplayed during actual operation.

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D TR MR RS CS TD9600 TM ER CD RD

Handshake Display

When two modems establish aconnection, they engage in anexchange known as a handshake.While a handshake is taking place,the modem displays several codesranging from H-01 to H-28 in thelower left corner of the EIA statusscreen. A handshake typically lastsfor up to 12 seconds and isaccompanied by various audibletones.

Checksum Screens

By pressing pushbutton 1 while theEIA status screen is displayed, youcan access two checksum screens,one for the main checksum andone for the data pump transmitterand receiver checksums. Thesechecksums provide data intendedfor use by servicing personnel. Thechecksum screens also show thesoftware revision levels (which arealso shown on the power-onscreen).

7.6.2 OTHER STATUS SCREENS

QUALITY SCREEN. The qualityscreen displays the quality of thereceived signal carrier as a numericvalue and as a horizontal bargraph. A low numeric valueindicates good signal quality. Thebest possible signal quality isindicated when the bar graphextends all the way to the rightedge of the LCD.

D=Dial line occupied

R=Ringing (R appears in sameposition as D.)

S=Connection secured by securityhandshake (S appears in sameposition as D. S and D may flashalternately.)

TR=Data Terminal Ready

MR=Data Set Ready

RS=Request to Send

CS=Clear to Send

TD=Transmit Data

9600, 4800, etc. = Data speed(“idle”—meaning the modem isoff-line—or H-01, H-14, etc., mayalso be displayed in the data speedposition; see following text.)

TM=Test mode

ER=Error (poor signal quality)

CD=Carrier Detect

RD=Receive Data

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MODEM 32144

LINE LEVELS SCREEN. Thisscreen shows the preset level of thetransmit signal (TX) and themeasured level of the receivesignal (RX).

The RX value is the approximatelocal receive level of the incomingsignal. The range of measurementfor RX is from 0 to –43 dBm in 1.5-dBm increments. If the signal levelis less than the carrier detectthreshold, <CD will be displayed.

ECHO CHARACTERISTICSSCREEN. This screen displays thecharacteristics of the echo portionof the receive signal. Specifically, itshows milliseconds of delay and theoffset frequency in Hertz.

CHANNEL FREQUENCYOFFSET. This screen displays thefrequency offset of the receivesignal in Hertz.

THROUGHPUT SCREEN. Thisscreen functions only if errorcorrection has been enabled. Itshows the rate (in bits per second)at which characters are beingaccepted by the modem from theDTE.

PACKET SCREEN. The packetscreen functions only when errorcorrection is enabled. It has threecomponents, as explained next.

• SIZE. Shows size of data packets(MNP) or blocks (V.42/V.42bis) currently beingtransmitted. MNP uses“shorter” packets to transmitthrough noisy lines and“longer” packets (which allowgreater throughput) when lineconditions are good. Themaximum MNP packet size is256 characters (MNP classes 4and 5) or 64 (MNP classes 1-3).The block size for V.42/V.42 bisis fixed at 128 characters.

• TRANSMITTED (TX). Numberof packets or blocks transmittedsince the connection wasestablished (or since counterreset).

• ERRORS (ER). Number ofretransmissions (due to dataerrors) since the connectionwas established (or since thecounter was reset).

To reset the TX and ER counters,press pushbutton 2 while thepacket screen is displayed.

MODE AND RATE SCREEN.This screen shows the followingdata:

• MODE. Below MODE, thisscreen indicates the error-correction status:

- NORMAL, Error correction andbuffer mode are both inactive.

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- V42, V.42 error correction(LAPM) is active.

- V42 bis, V.42 bis error correction(LAPM with data compression)is active.

- MNP 01 – MNP 05, MNP errorcorrection is active.

- BUFFER, Buffer mode is active.

- OFFLINE, Modem is off-line.

• RATE. This screen shows thedata rate of the DTE.

7.7 Rate Change ScreenIf V.32bis mode and the RateRenegotiation Procedure (RRP)option are both enabled, themodem will automatically adjustduring data transmission to ahigher or lower data rate,depending on the receive signalquality. For diagnostic purposes,the RATE screen (accessed fromscreen 3 of the MAIN MENU) maybe used to manually initiate speedrenegotiation from the front panel,as explained below.

The RATE screen is displayedonly if V.32 bis mode is enabled(via Summary Setup, V.32 Modeoption).

If you select DOWN from theRATE screen, the modem will fallback to the next lower speed. If youselect UP, the modem will fallforward to the next higher speed—if the signal quality is good enough.The range within which themodem can fall forward or fallback is limited by the minimumand maximum rates set via theSpeed Limit option. After youselect UP or DOWN, the LCD willautomatically switch to the EIAstatus screen so you can see theresult of the rate change request(i.e., the current data rate, which isdisplayed in the lower left corner ofthe EIA status screen). However, ifthe local modem has reached theminimum or maximum speed, itwill not switch to the EIA statusscreen.

NOTEA request to increase thedata rate may result in nochange in the data rate if thesignal quality is poor.

If you manually initiate speedrenegotiation with RRP enabled,the modem will automaticallyrenegotiate the speed (again) afterreceiving good signal quality for 4 seconds. If the originate modemattempts to negotiate a rate that is lower than the minimum ratesetting of the answer modem, theanswer modem will disconnect(GSTN cleardown).

144

MODEM 32144

7.8 Local Modem Diagnostics Local modem diagnostics are fortesting the modem and its adjoin-ing system. These tests are accessedfrom the main menu and are easilyperformed if the modem isattached to DTE or an externalBERT.

7.8.1 ANALOG LOOPBACK (ALB) TEST

Analog loopback testing allows theuser to test the local modem and itsassociated terminal independentlyfrom the telephone interface andthe remote modem. Fig. 7-1 showsthe connections automaticallymade during the test.

LOCAL MODEM

DATA TERMINAL EQUIPMENT(DTE) AT LOCAL SITE

TRANSMITTER

RECEIVER

Fig. 7-1. Analog Loopback Test.

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In Hayes emulation mode only,the ALB test can be initiated usingthe command &T1 (preceded byAT). In any mode, the ALB test canbe initiated by using the modem’sfront panel controls, as explainedin the following paragraphs.

Make sure the modem is idle,that the data rate is the same asthat of the DTE and that the DTRcircuit is on. (If TR is present onthe EIA status screen, the DTRcircuit is on.)

From screen 2 of the LCD MAINMENU, select TEST. This will takeyou to screen 1 of the LOCALTEST menu, where ALB will bedisplayed as one of the testselections. Select ALB.

The ANALOG LOOPBACKscreen will be displayed, with ONand OFF as the possible selections.

Select ON to activate the test. (Ingeneral, the DSR during ALB testoption discussed in chapter shouldbe left ON—the default selection—to avoid disrupting the DTE andDTE software operations.)

The EIA status screen will bedisplayed while the test is beingconducted. Ensure that test data is being generated. Watch for dataerrors. By transmitting test dataand comparing it with the receivedcopy, the DTE and modem arechecked for proper operation.

To end the test, press the ENTpushbutton to return to theANALOG LOOPBACK screen, and then select OFF.

7.8.2 ANALOG LOOPBACK SELF-TEST(ALBST)In the analog loopback self-test, the modem is placed in analogloopback and data is sent andreceived by an internal 511-bitpattern generator and receiver;therefore, no DTE or externalBERT is necessary. Fig. 7-2 showsthe data flow for this test.

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MODEM 32144

Fig. 7-2. Analog Loopback Self Test (ALBST).

The SELFTEST screen will bedisplayed, with ON and OFF as thepossible selections. Select ON toactivate the test. The EIA statusscreen will be displayed while thetest is being conducted. If “ER” ispresent on the front panel, dataerrors have occurred. The ERindicator may flash on when thetest is first turned on, but it shouldquickly go out and remain off untilthe end of the test.

TRANSMITTER

PATTERNGENERATOR

RECEIVER

PATTERNDETECTOR

In Hayes mode only, the ALBST can be initiated using thecommand &T8 (preceded by AT).In any mode, the ALBST can beinitiated by using the modem’sfront-panel controls, as follows:

From screen 2 of the LCD MAINMENU, select TEST. This will takeyou to screen 1 of the LOCALTEST menu, where ALBST will be visible as one of the selections.Select ALBST.

147


To end the test, press the ENTpushbutton to return to theSELFTEST screen, and then select OFF.

7.8.3 ANALOG LOOPBACK SELF-TESTWITH ERRORS (ST/E)In the analog loopback self testwith errors, data is sent andreceived by an internal 511-bitpattern generator and receiver;therefore, no DTE or externalBERT is necessary. This test differsfrom the ALBST in that errors areinjected into the data flow everyfew seconds. The data flow is thesame as that shown in figure -2 (the ALBST).

To run this test, follow thesesteps:

From screen 2 of the LCD MAINMENU, select TEST. This will takeyou to screen 1 of the LOCALTEST menu, where ST/E will bevisible as one of the selections.Select ST/E.

The SELFTEST W/ERRORscreen will be displayed, with ONand OFF as the possible selections.Select ON to activate the test. TheEIA status screen will be displayed.The ER indicator should flash everyfew seconds, indicating that thepattern generator and detector areworking. Errors are injected everyfew seconds. To end the test, pressthe ENT pushbutton to return tothe SELFTEST W/ERROR screen,and then select OFF.

7.8.4 EXTERNAL ANALOG LOOPBACK(ALBX) TEST

The external analog loopback testis available for 4-wire leased linemode only.

The ALBX test allows the user to test the local modem and itsassociated terminal and to verifythe availability of the leased linecircuit. The test circuit does notinclude the remote modem. Fig. 7-3 shows the connectionsautomatically made during theALBX test.

NOTEThe ALBX test may result inerrors or may fail altogethereven where conditions aresatisfactory for normaloperation. This is becausethe test channel presentedto the modem during theALBX test.includes allimpairments of both theinbound and outboundchannels (amplitudedistortion, delay distortion,noise, etc.). The mainpurpose of the ALBX test isto verify that the modem isconnected to the leased lineand that the leased linecircuit is complete. The testis not meant to assess thesuitability of the leased line.

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MODEM 32144

The ALBX test can be initiatedby using the modem’s front panelcontrols, as explained in thefollowing paragraphs.

Make sure the local modem isnot in communication with theremote modem, that the data rateis the same as that of the DTE andthat the DTR circuit is on. (If TR ispresent on the EIA status screen,the DTR circuit is on.)

From screen 2 of the LCD MAINMENU, select TEST. Go to screen 2of the LOCAL TEST menu andselect ALBX.

LOCAL MODEM


RECEIVER

EXTERNAL LOOPBACK(LEASED LINE)

TRANSMITTER

Fig. 7-3. External Analog Loopback (ALBX) Test.

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The ANALOG LOOP(EXT)screen will be displayed, with ONand OFF as the possible selections.

Select ON to activate the test. (Ingeneral, the DSR during ALB testoption discussed in chapter shouldbe left ON—the default selection—to avoid disrupting the DTE andDTE software operations.)

The EIA status screen will bedisplayed while the test is beingconducted. If no external loopbackis present, the status screen willdisplay an “IDLE” message. If aloopback is present, handshake-sequence codes will appear (H-01,etc.), followed by the modemspeed. Make sure that test data isbeing generated. Watch for dataerrors. By transmitting test dataand comparing it with the receivedcopy, the DTE and modem arechecked for proper operation.During the ALBX test, RD (receivedata) may appear on the statusscreen even though no data isbeing received—this is normal.

On a flat line, the MODEMmodem in ALBX test mode willtrain and remain running acrossthe following range of signal loss:in V.32 mode, 0–51 dBm (0–52dBm at 12.0 Kbps); for V.33operation, 0-47 dBm; and for Bell208A/B operation, 0–37 dBm. Ifsignal loss exceeds these limits, thetest may not start or may be halted.

During the ALBX test, themodem will attempt to retrainupon loss of carrier. In switchedcarrier mode, the modem willattempt to retrain upon loss ofRTS.

To end the test, press the ENTpushbutton to return to theANALOG LOOP(EXT) screen, and then select OFF.

7.8.5 EXTERNAL ANALOG LOOPBACKSELF-TEST (ALXST)The external analog loopback selftest is available for 4-wire leasedline mode only.

The ALXST places the modem inanalog loopback and causes data tobe sent and received by an internal511-bit pattern generator andreceiver; therefore, no DTE orexternal BERT is necessary. Asshown in Fig. 7-4, the test circuitincludes the leased lines (theexternal loopback).

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MODEM 32144

NOTEThe ALXST may result inerrors or may fail altogethereven where conditions aresatisfactory for normaloperation. This is becausethe test channel presentedto the modem during theALXST includes allimpairments of both theinbound and out-bound

channels (amplitude distor-tion, delay distortion, noise,etc.). The main purpose ofthe ALXST is to verify thatthe modem is connected tothe leased line and that theleased line circuit iscomplete. The test is notmeant to assess thesuitability of the leased line.

TRANSMITTER

PATTERNGENERATOR

RECEIVER

PATTERNDETECTOR

EXTERNAL LOOPBACK(LEASED LINE)

Fig. 7-4. External Analog Loopback Self Test (ALXST).

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The ALXST can be initiated from the modem’s front panel, as follows:

From screen 2 of the LCD MAINMENU, select TEST. Go to screen 2of the LOCAL TEST menu andselect ALXST.

The ANALOG ST (EXT) screenwill be displayed, with ON and OFFas the possible selections. SelectON to activate the test.

The EIA status screen will bedisplayed while the test is beingconducted. If no external loopbackis present, the status screen willdisplay an “IDLE” message. If aloopback is present, handshakesequence codes will appear,followed by the modem speed. If“ER” is present on the front panel,data errors have occurred. The ERindicator may flash on when thetest is first turned on, but it shouldquickly go out and remain off untilthe end of the test.

The information at the end ofthe previous section (for the ALBXtest) concerning signal loss, loss ofcarrier and loss of RTS also apply tothe ALXST.

To end the test, press the ENTpushbutton to return to theANALOG ST (EXT) screen, and then select OFF.

7.8.6 DIGITAL LOOPBACK TEST (DLB)Digital loopback testing determinesthe operational performance of thelocal modem, the remote modem,and the telephone line as acomposite system. For this test, datamust be sent and received at theremote modem. This testregenerates the data and loops itback to the remote modem. As withthe ALB test, a comparison of theresults of the DLB test can indicatewhether or not the DTE isperforming satisfactorily. Acomparison of the results of theALB and DLB tests can helpdetermine whether the modem orthe telephone line is defective.

In the DLB test, the data to besent and received is originated andchecked by the DTE or externalBERT. Fig. 7-5 shows the data flowfor this test.

152

MODEM 32144

Fig. 7-5. Digital Loopback (DLB) Test.


REMOTEMODEM

RECEIVER

LOCAL MODEM

TRANSMITTER

RECEIVER

TRANSMITTER

In Hayes mode only, the DLB testcan be initiated using thecommand &T3 (preceded by AT).In any mode, the DLB test can beinitiated using the modem’s front-panel controls, as follows:

From screen 2 of the LCD MAINMENU, select TEST. Go to screen 2of the LOCAL TEST menu andselect DLB.

The DIGITAL LOOPBACKscreen will be displayed, with ONand OFF as the possible selections.Select ON to activate the test. TheEIA status screen will be displayedwhile the test is being conducted.Make sure that test data is beinggenerated. Watch for data errors.By transmitting test data andcomparing it with the receivedcopy, the DTE is checked forproper operation. To end the test, press the ENT pushbutton to return to the DIGITALLOOPBACK screen, and thenselect OFF.

153


7.9 Remote Modem DiagnosticsThe modem is capable ofperforming two tests on compatibleremote modems: remote digitalloopback (RDL) and remote digitalloopback self-test (RDLST). If aproblem is encountered and thelocal modem passes all diagnostictests, the local modem can test theremote modem.

There are two (noncontiguous)REMOTE TEST screens on themodem LCD: (1) The remote testsare initiated from the REMOTETEST menu. (Select RMT fromMAIN MENU screen 2, and thenselect TEST. Then select the testtype.) (2) A remote test cannot be initiated unless the Remote Testoption is enabled on the remotemodem. This option (alsoREMOTE TEST on the LCD) isaccessed via SETUP screen 4.

7.9.1 REMOTE DIGITAL LOOPBACK(RDL) TEST

The RDL test (Fig. 7-6) allowstesting of the local modem, remotemodem and telephone line fromthe local site.

In Hayes mode only, the RDL test can be initiated using thecommand &T6 (preceded by AT).In any mode, the RDL test can beinitiated from the modem’s frontpanel, as follows:

Both modems should be on-lineand should be tested at the datarate used by the DTE. Ensure thatthe DTR circuit is on. (If TR ispresent on the EIA status screen,the DTR circuit is on.)

From screen 2 of the MAINMENU, select RMT, and then selectTEST. From the REMOTE TESTmenu, select RDL.

154

MODEM 32144

Fig. 7-6. Remote Digital Loopback (RDL) Test.

7.9.2 REMOTE DIGITAL LOOPBACKSELF-TEST (RDLST)The RDLST allows testing of thelocal modem, remote modem andtelephone line from the local siteas did the previous test, except that the test data is generated byinternal modem circuitry asopposed to a DTE or externalBERT. Fig. 7-7 shows theconnections automatically made during the test.


LOCALMODEM

RECEIVER

REMOTE MODEM

TRANSMITTER

RECEIVER

TRANSMITTER

From the REMOTE DIGITLOOP screen, select ON to activatethe test. The status screen will bedisplayed as the test is beingconducted. Make sure that test datais being generated. Watch for dataerrors. By transmitting test dataand comparing it with the receivedcopy, the modems as well as thetelephone line can be checked forproper operation.

To end the test, press the ENTpushbutton to return to theREMOTE DIGIT LOOP screen,and then select OFF.

155


In Hayes mode only, the RDLST can be initiated using thecommand &T7 (AT &T7). In anymode, the RDLST test can beinitiated from the front panel asfollows:Both modems must be on-line.From screen 2 of the MAIN MENU,select RMT, and then select TEST.From the REMOTE TEST menu,select RDLST.

From the RDL SELFTESTscreen, select ON to activate thetest. The status screen will bedisplayed as the test is beingconducted. If “ER” is present onthe status screen, the modem isdetecting errors. If numerouserrors are detected, steps should betaken to try to identify their source.

PATTERNGENERATOR

PATTERNDETECTOR

TRANSMITTER

RECEIVER

TRANSMITTER

RECEIVER

LOCAL MODEM

REMOTE MODEM

Fig. 7-7. Remote Digital Loopback Self Test.

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MODEM 32144

6.1.2 2 = DIALER MODE (DIAL V.25BIS SCREEN)If you enable the V.25 bisautodialer using the Dialer Modeoption, no other options will bechanged. To enable the autodialerthis way, select DIALER fromSETUP screen 2. Then press theright arrow pushbutton to go to theDIAL V25 bis screen (screen 2).Select the V.25 bis data protocolthat is appropriate for the DTE tobe used: asynchronous (Asyn);synchronous, character-oriented(Syn_c); or synchronous, bit-oriented (Syn_b).

6.1.3 DTR DIALING IN V.25 BIS MODE

An alternative to using the V.25bisCRS command to dial a storednumber is to use the DTR dialingoption. With DTR dialing enabled,the autodialer will dial the numberstored in phone cell 0 when DTRgoes high for at least 50 ms.

To enable V.25 bis DTR dialing,use the Summary Setup feature (asdescribed in appendix ) to changethe parameter for Penril/V25 bisDTR dialing to 0. Do not selectDTR dialing via the front-panelDIALER screen; this will not enableDTR dialing for V.25 bis mode. TheSummary Setup Penril/V25 bisDTR dialing option applies toeither V.25 bis mode or Penrilmode—whichever is enabled;therefore, for V.25 bis DTR dialing,the V.25 bis autodialer must beenabled.

6.2 V.25 bis Autodialer CommandsIn asynchronous applications, V.25bis commands are issued directlyfrom the DTE keyboard or throughcommunications software. Insynchronous applications, the V.25bis commands can be used tofacilitate computer-controlledcommunications.

Punctuation and spaces may beused with V.25 bis commands forclarity, but they are not required. If used, they will be ignored by the modem. One exception is the colon (:), which instructs theautodialer to wait for a dial tone.

The V.25 bis commands aredescribed below and aresummarized in Table 6-1. See Table6-3 for explanation of the codesthat may be displayed in responseto commands.

CIC - CONNECT NEXTINCOMING CALL. The CICcommand instructs the autodialerto answer the next incoming call.After the modem goes off hook,the modem will answer the nextcall only if auto-answer is enabledfrom the front panel.

129


CRN - CALL REQUEST, NUMBERPROVIDED. (Syntax: CRN5557979) By using the CRNcommand, you can dial a numberdirectly from the DTE keyboard.Numbers from 0 through 9 can be dialed, and if tone dialing isenabled, the characters A, B, C, D,# and * can also be dialed.

The dialing parameters listed intable -2 can be used with the CRNcommand to specify how or when a number should be dialed. Forexample, the command line CRN:T3331234 instructs the autodialerto wait for a dial tone (:) and thentone dial (T) the number 333-1234.

CRS - CALL REQUEST, ADDRESSPROVIDED. (Syntax: CRS 2) TheCRS command allows you to dial astored number simply by specifyingits memory address (phone cell).In the example given above, theautodialer will dial the numberstored in phone cell 2. Thenumber must first be stored in the specified phone cell using the PRN command (Table 6-1).

DIC - DISREGARD INCOMINGCALLS. The DIC commandinstructs the autodialer not toanswer incoming calls. The DICcommand is canceled when theCIC command is issued or themodem is reset. In the event of a reset, the modem will answer ifauto-answer is enabled from thefront panel.

PRN - PROGRAM NORMAL(STORE NUMBER). (Syntax: PRN1;5551212) The PRN command isused to store a number or dialstring in a phone cell so it can bedialed later by specifying only thephone cell number. As shownabove, PRN is followed by thephone cell number, a semicolonand the phone number to bestored. After a number is stored, it can be dialed using the CRScommand. Any of the characterslisted in Table 6-2 may be stored.

Ten phone cells (0-9) areavailable for phone numberstorage. Each cell can hold amaximum of 25 characters,although cells 1 through 9 willautomatically expand to the nextempty phone cell if loaded withmore than 25 digits. Even if astored number is continued toanother cell, the maximumnumber of characters that can bestored is 36. You cannot store anumber in a phone cell unless it is empty. To clear a cell, enter PRNand the phone cell number,without a phone number. Only cell 0 can be accessed from themodem’s front panel (via thePHONE LCD screen).

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MODEM 32144

RLN - REQUEST STOREDNUMBER(S). RLN can be used torequest a list of all stored numbersor to show the number stored in aspecific phone cell. RLN, usedalone, requests a list of all storednumbers. The DTE display willshow the stored numbers as follows:LSN 0; 301 555 1234LSN 1; 301 123 4567LSN 2; 301 555 5555

(and so on through phone cell 9)

If a phone cell number isspecified after RLN, e.g., RLN 5,the DTE display will show only thenumber stored in the specifiedphone cell.

How to Disconnect a Call

To disconnect a call locally, useyour communication software toforce DTR to go low, or selectHANGUP from the front-panelAUTO-DIAL screen.

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Table 6-1. V.25bis Autodialer Commands

Command Function

CIC Connect next incoming call.

CRN n Call request—dial number (n) entered on DTE

keyboard.

CRS m Call request—dial number stored in specified

memory address (m).

DIC Disregard incoming calls.

PRN m; n Program normal—store number or dial string n in

memory address m.

RHA Switch to Hayes dialing mode (also resets modem

configuration).

RLN Request list of all stored numbers.

RLN m Request to see number stored at address m.

n represents a number to be dialed or stored (e.g., 5557979);

m represents a memory address where a number is stored (0-9).

A comma (,) can be included in a dial string to effect a pause.

A colon (:) can be included to instruct the autodialer to wait for a dial tone

before proceeding.

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MODEM 32144

6.3 Dialing ParametersTable 6-2 lists dialing parametersthat may be used with the CRNcommand to modify dialingoperations.

Table 6-2. V.25 bis Dialing Parameters(Table also applies to Dumb mode and Bell 208 operation)

Characters that can be pulse or tone dialed: 0-9Can only be tone dialed: A, B, C, D, #, and *

L Links a phone number to

another number to be dialed

as an alternate when the primary

number is busy or does not

answer. See L—Link in Section 5.4.

P Sets pulse dialing mode.

T Sets tone dialing mode.

W or : (colon) Wait 30 seconds for dial tone before

proceeding.

[CR] or . Required at end of dial command line.

(carriage return [CR] is sent from DTE keyboard.

or period) Dumb/208 mode only: period has same

function, but may be entered via the

front panel (PHONE LCD screen).

, (comma) or < Pause before processing next character

in dial string.

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Table 6-2. V.25 bis Dialing Parameters(Table also applies to Dumb mode and Bell 208 operation)

Characters that can be pulse or tone dialed: 0-9Can only be tone dialed: A,B, C, D, # and *

@ Wait for silence.

! (exclamation) Flash hook

L, P, T, and W may be entered as upper or lowercase letters. Spaces or

hyphens (-) may be used as separators for clarity; they will have no effect.

6.4 V.25 bis Result CodesTable 6-3 explains the result codes,or responses that may be displayedon the DTE monitor in response toV.25 bis commands.

134

MODEM 32144

Table 6-3. V.25 bis Result Codes

Code Meaning Sent by—1

CFI AB Call failure—call aborted because of ORG

loss of DTR or because HANGUP was

selected from front-panel AUTO-DIAL

screen.

CFI CB Call failure because DCE is busy. ORG

(Modem dialing or handshaking as

a result of a front-panel dial

request.)

CFI ET Call failure because of busy signal. ORG

(Engaged tone.)

CFI ND Call failure—no dial tone. Modem did ORG

not detect dial tone or line current

during dialing or handshaking.

CFI NS Call failure—call request specified ORG

an address that does not contain

a stored number. (No stored

number.)

CFI NT Call failure—no answer tone. Remote ORG

unit answered but did not issue

answer tone.

1Column 3 indicates which modem sends the result code. (ANS/ORG indicates

answer and/or originate modem.)

A semicolon is used to separate parameters,. e.g., LSN 4;5559797.

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Table 6-3. V.25bis Result Codes (continued)

Code Meaning Sent by—1

CFI RT Call failure—ring tone. Ringback ORG

detected, but no answer.

CNX Call connecting. ANS/ORG

INC Incoming call. ANS

INV CU Invalid—command unknown. ANS/ORG

INV MS Invalid message (command) syntax. ANS/ORG

INV PS Invalid parameter value. Specified ANS/ORG

parameters are out of range for

command used.

LSN List of stored numbers. LSN is ANS/ORG

followed by memory address,

stored number, next memory

address and stored number, etc.

VAL Valid—command accepted; waiting ANS/ORG

for next command.

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MODEM 32144

6.5 Message FormatThe message format for V.25 bisDTE-to-DCE communications issummarized below:

6.5.1 ASYNCHRONOUS

MARK|MESSAGE|CR|LF|MARK

This format uses one start bit, 8-bit data units, and a 1-unit stopbit. The 8-bit data units are formedby a 7-bit IA5 character and aneven parity bit.

6.5.2 SYNCHRONOUS, CHARACTER-ORIENTED

|SYN\SYN\STX|MESSAGE|ETX|

This format uses consecutive 8-bitdata units formed by a 7-bit IA5character and an odd parity bit.

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||FLAG|ADDR|CTRL|MESSAGE|FCS|FLAG|

Consecutive 8-bit data units areused within the message andsubmitted to the HDLC framing(zero insertion). The 8-bit dataunits are formed by a 7-bit IA5character and an off parity bit.

6.5.3 SYNCHRONOUS, BIT-ORIENTED

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MODEM 32144

• ESCAPE SEQUENCE (+++).The escape sequence causesthe modem to escape from thedata transfer mode so it caninterpret commands.(Alternate characters for theescape sequence can beassigned via S register S2.)

• ATTENTION CODE. AT, theattention code, must begin allcommand lines. There are afew exceptions—but only a few.

• COMMAND SEQUENCE. Fordialing, a command line beginswith AT and is followed by Dand the phone number. Othercommands should be placedbefore the dial command—orafter the dial command if it isterminated with a semicolon—for example:

AT M2 V1 D 555-1212; S2=1O

This instructs the modem to:Keep speaker on (M2), send wordresult codes (V1), dial (D) 555-1212, end dial command (;), setregister 2 to 1 (S2=1), and go on-line and wait for carrier (O).

Characters not in the commandset are ignored during the dialcommand. For this reason,punctuation or spaces can beincluded in the telephone numberto make it easier to read:

AT DT 9,(212)555-1234 or AT DT9, 212 555 1234

• A/ COMMAND. Repeats thecommands included in theprevious command line.Because the AT is alsorepeated, no AT is needed tobegin this command, nor is acarriage return needed. A/ isuseful for redialing a telephonenumber.

• BACKSPACE KEY. Thebackspace key deletes the lastcharacter entered (providedthere is no intervening carriagereturn) and can be used forsimple editing.

• CARRIAGE RETURN [CR]. Acarriage return is required atthe end of a command line.The modem will not execute acommand without it. A carriagereturn is sent from the DTEkeyboards; a period, which maybe entered via the modem’sfront panel (PHONE LCDscreen), has the same function.(On most keyboards, thecarriage return [CR] key islabeled “Enter” or “Return.”)

• DIAL COMMANDMODIFIERS. Several modifierscan be used with the basic D(dial) command to alter dialingoperations. These modifiers arelisted and explained brieflybelow—they are explained indetail in Section 5.4

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Dial command modifiers:

L—Links a phone number toanother number to be dialed as analternate.

P—Sets pulse-dialing mode.

S=m—Dial number stored atmemory location m.

T—Sets tone-dialing mode.

W or : (colon)—Pause for 2seconds.

, (comma)—Pause for 2 seconds.

; (semicolon)—Return tocommand state after dialing.

@—Wait for silence.

! (exclamation)—Flash hook

With few exceptions, dialcommand modifiers will functiononly if they are used in a commandline with the D command orincluded in a stored number. Acarriage return of period must beused at the end of a dial string. Anexample of a command line withtwo dial modifiers is:

AT DT 9,555-1212

The modifier T instructs themodem to tone dial, and thecomma instructs it to pause afterdialing 9 before dialing theremaining digits.

MISSING PARAMETER. Amissing parameter is interpreted as a zero. For example, the Ecommand (echo) can be sent aseither E0 or E1, but if an E aloneis sent, the modem will interpret itas if an E0 was sent.

COMMAND BUFFER. Thecommand buffer can hold amaximum of 40 characters. If the command line exceeds 40characters, the modem refuses to execute any portion of thecommand line and sends an errormessage. The AT at the beginningof the command line, controlcharacters, and spaces do not takeup space in the command buffer.Punctuation (except for spaces)does take up space in thecommand buffer.

5.2 Result CodesResult codes (Table 5-2) aremessages sent by the modem to theDTE monitor in response to yourcommands. Result code options are selected using the V and Xcommands, as explained below.

Result codes may be words (V1command) or digits (V0). Wordcodes are preceded and followedby a carriage return, line feedsequence. Digit codes are onlyfollowed by a carriage return.

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MODEM 32144

Result codes 0-4 comprise thebasic result code set: OK,CONNECT, RING, NO CARRIER,and ERROR. Codes 5-43 provideadditional response information, asexplained in Table 5-2. Variouscombinations of these codes can beenabled or disabled by using the Xcommand and its four parameters,as explained later under X—SELECT RESULT CODE.

NOTEWith the default Hayes modesettings in effect, themodem transmits resultcodes to the DTE. In someinstallations, this may causeundesirable interaction withthe attached DTE. If suchinteraction occurs, resultcodes for incoming callsshould be suppressed(using the command AT Q2).

5.3 Transmission SpeedThis section applies only toconnections made without errorcorrection or buffering (V.42/V.42bis, MNP and Buffer Modeoptions).

Transmission speed is governedby the speed of the system withwhich you wish to communicate.You must set the transmissionspeed of your computer by setting aswitch in the hardware or by issuinga software command. (Refer toyour computer documentation.)When the modem originates a call,it automatically detects and adjusts

to the transmission speed set whenthe communication port wasinitialized.

When answering a call, themodem determines thetransmission speed from the carriersignal of the originating modem.Change the speed (baud) setting of your equipment to match that ofthe remote system. Otherwise,unintelligible data will appear onyour screen. (Depending on theparameter used with the Xcommand, the speed will beindicated by the CONNECTresponse code.)

Autobaud

When a call is originated in Hayesmode, the AT attention codecauses the modem to autobaud.The speed at which the modemautobauds defines the speed limitfor subsequent connections andoverrides any front panel SpeedLimit or DTE Speed settings. If theunit is not autobauded, the defaultinterface rate is 38,400 bps.

NOTEIf AT is entered at one speedand followed by a carriagereturn [CR] at anotherspeed, the modem will notrecognize any furthercommands until a [CR] isentered at the same speedof the AT.

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5.4 Compatible CommandsAll that can be used with themodem are listed in Table 5-1(near the end of the chapter.)More detailed information isprovided below for selected Hayescommands—particularly thoseused to answer and originate calls,and other commonly usedcommands. For Hayes commandsthat control modem options,additional information on optionsmay be found in Chapter 5.Commands are listed inalphabetical order in this sectionand in Table 5-1.

For most commands there areparameters—numerical values usedwith the commands that specify thefunction of the command. Forexample, the command L controlsthe modem’s speaker volume. L2sets the volume to medium. Thedefault value is a predeterminedvalue which is in effect the firsttime the modem is powered up orwhen a reset command is given.The possible parameters anddefault value for each commandare shown in Table 5-1.

A—ANSWER. The A commandimmediately puts the modem intothe answer mode. The modem willnot execute any command enteredin the command line after A.

The A command is used tomanually answer an incoming callor to transfer a call between twoindividuals to a communicationbetween their computers: Oneperson enters AT A while the otherenters AT D.

A/-REPEAT PREVIOUSCOMMAND. A/ is most commonlyused to redial a telephone numberthat results in a busy signal. The ATprefix is not used with A/, and nocarriage return is required.Commands are available forrepetition in the command bufferonly until AT is entered or power to the unit is turned off. A/ will notwork following an AT or powerOFF-power ON.

D-ORIGINATE MODE FORDIALING. The modem dials thenumber that follows and attemptsto go on-line. The dial command Dis followed by—

• A telephone number to bedialed, or

• A string consisting of a phonenumber and dial commandmodifiers (e.g., T, P, and ;).

An example of the D commandis AT D3331234.

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MODEM 32144

In response to this command, themodem dials the telephonenumber 333-1234, and then waitsfor a carrier tone from the distantmodem (default wait time, 30seconds). If the modem is able to establish a call, it gives aCONNECT result code, indicatingthat it is on-line. If it cannotconnect, it will use a different resultcode , such as NO CARRIER, BUSY,or NO DIALTONE.

The characters that can be dialedare 0 through 9, A, B, C, D, #, and*.

The dial command modifiers arelisted in the preceding CommandGuidelines section.

AT D—the dial commandwithout a telephone numbercauses the modem to pick upthe telephone line without dialinga number.

DS—DIAL STORED NUMBER.The DS command instructs themodem to dial a phone number ordial string previously stored usingthe &Z command. The syntax isDS=m, where m specifies thememory location where thenumber to be dialed will be stored.Up to ten numbers may be storedin memory locations 0-9. S=m maybe placed anywhere in the dialstring for example, AT D2345S=2will dial 2345 and the number

stored in memory location 2.H—TELEPHONE SWITCH

HOOK. The H command on-hook)is used to terminate a call. (On-hook corresponds to off-line.)H may also be used to alternatebetween voice and datatransmission during the same call(if your communication softwaresupports this capability).

The H1 command (off-hook)activates the telephone line relay,causing a dial tone to be sent (after a 2-second delay). For mostpurposes, this command is notnecessary, since the switch hook isautomatically activated when themodem originates or answers a call.

L—LINK. The L dial modifier isused to link one phone number toanother so that one may bedesignated as an alternate numberto be dialed if a connection cannotbe made to a primary number. TheL parameter must be used after aphone number, and prior to acarriage return or period. Anumber is used after L to specify;the memory address (0-9) thatcontains the number to be linkedto the first number:

AT D 555-1212 L5

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NOTEL may also be used in V.25bis mode with the CRNcommand (instead of AT D),in Dumb mode and in 208operation. In Dumb mode or208 operation, L is storedvia the PHONE screen. In allcases, L is used the sameway and has the samefunction as described here(except that AT D is notused.)

Two or more addresses may be linked in a cyclic fashion toalternate dialing until a connectionis established.

Contents of memory location 0:555-1212 L1



With the memory locationsloaded as shown above, if thecommand AT DS=0 is issued, theautodialer will go to location 0 anddial the number stored there. Ifunable to connect, the L1command stored in location 0 willdirect the autodialer to dial thenumber in location 1. In similarfashion, the L2 stored in memorylocation 1 directs the autodialer tolocation 2 (assuming a connectioncannot be made); and the L0command stored in location 2directs the autodialer back tolocation 0. The numbers will be

dialed in a loop until a connectioncan be established or until 10 callshave been attempted.

O—FORCED ON-LINE. Thiscommand applies to asynchronousoperation only. When the modemis on-line, you can return to thecommand state by entering theescape code (+++). After thedesired command has beenexecuted, use the O command to force the modem from thecommand state to the on-line state.

P—PULSE DIAL. The Pcommand instructs the modem topulse dial. It can be enteredanywhere in the dialing string:AT P5551212; or it can be enteredalone, followed by a carriagereturn, AT P, in which case allsubsequent telephone numbers will be pulse dialed. If the dialcommand does not specify whichdialing mode to use, the modemdefaults to the last mode specified.

S—MODIFY S REGISTER. This command is used to writeinformation to a specified Sregister. The syntax is Sr=n, where ris the number of the register to bemodified and n is the value to bewritten to it; for example:

AT S7=30

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MODEM 32144

This command would change thevalue of register S7 to 30. If youenter just =5, the autodialer willchange the value of the last registerused to 5. More information on Sregisters is included later in thischapter.

S?—READ S REGISTER. Thiscommand instructs the autodialerto read the contents of thespecified S register. The syntax isSr?, where r specifies the register tobe read. For example, S7? reads thevalue of register S7. The value isdisplayed on the computer orterminal monitor. If you enter ? byitself, the autodialer will display thevalue of the last register used; if = isentered by itself, the autodialer willdisplay the number of the lastregister used (e.g., S2). Forinformation on how to interpret Sregister values, see Table 5-3.

T—TONE DIALING. Thiscommand causes a telephonenumber in the dial commandstring to be dialed using tonesignals. (See the P command above for additional information.)

W—WAIT FOR DIAL TONE.The W command (or colon) isused in a dial string to instruct themodem to wait for a dial tonebefore proceeding. The wait time(30 seconds by default) can beadjusted by changing the value inregister S7. If no dial tone isdetected within the specified time,the modem will hang up and give aNO DIALTONE result code (if this

result code is enabled by the Xcommand).

Z—RECALL STORED USERPROFILE. The Z command resetsthe modem and recalls a profile ofthe modem configuration settingspreviously saved using the &Wcommand. The profile isdesignated as profile 0 or profile 1when it is saved using the &Wcommand.

,—PAUSE. A comma causes themodem to pause for 2 seconds (ortime specified in register S8)before processing the nextcharacter in a dial string orcommand. This command is usedto place an outside call through aPBX switchboard, where 9 has tobe dialed to gain outside access—the pause allows time for the dialtone to occur before the modemdials the number.

AT D9,3331234

Similarly, a comma may be usedto cause the modem to wait for asecond dial tone before beginningto dial a telephone number.Multiple commas may be used toincrease the pause time.

;—FORCED COMMAND STATE.A semicolon placed at the end of adial command causes the modemto return to the command stateafter dialing without disconnecting.

The following examples illustratehow the ; command is used:

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The first example is a bankingtransaction: The command ATD333-1234; dials the bank’s phonenumber and returns the modem tothe command state. After the OKprompt is displayed on the DTE,the command AT D T 0901# isentered. This transmits theidentification number 0901 to the bank, and again returns themodem to the command state. Anaccount number and other datamay be transmitted in the sameway.

The second example illustratesone method of autodialing: Entera dial string that ends with asemicolon, for example, AT DT9,3331234. During the ring signal orwhen the call is answered, pick upthe phone and enter AT H. Youmay then use a telephoneconnected to the modem for voicecommunication.

@—WSAIT FOR SILENCEBEFORE DIALING. The @command is used to gain access toa system that does not provide adial tone. It tells the modem to waitfor 30 seconds or the time specifiedby a register S7 for one or morerings followed by 5 seconds ofsilence before processing the nextsymbol in the dial string.

!—INITIATE FLASH HOOK.The ! command causes the modemto go on-hook for 1/2 second. Thishas the same effect as holding theswitch-hook button on yourtelephone down for 1/2 second.

You may be able to use thiscommand for transferring calls.

&F—RECALL FACTORYCONFIGURATION. The &Fcommand restores the modem toits original factory configuration,using data stored in ROM.However, this change is notpermanent. If the modem is turnedoff or reset, the recalledconfiguration will be replaced withthe default stored profile. (See the&Y command.)

&V—VIEW ACTIVECONFIGURATION, ETC. Thiscommand displays the activemodem configuration, user profilesstored using the &W command,and phone numbers stored usingthe &Z command. When &V isinvoked, the DTE displays theconfiguration commands lastissued, including parameters used,and the values currently stored inthe S registers. The &V commandshould be issued as the lastcommand on a line.

&W—WRITE PROFILE TOMEMORY. The &W commandsaves the storable parameters of themodem’s active configuration bywriting the configuration profile tonon-volatile memory. By selectingeither &W0 or &W1, two differentuser profiles can be saved (profile 0or 1). One of these profiles will beautomatically restored wheneverthe modem is powered on or whenthe Z command is issued. (See the&Y and Z commands.)

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MODEM 32144

The &W command cannot beused to write changes to the userprofiles if the modem front panelhas been disabled by the FrontPanel Control option.

The parameters listed belowcannot be stored—they are all setby changing S register values (asindicated in Table 5-3):

S1—Ring countS2—Escape-sequence character (ASCII 43)S3—Carriage-return character (ASCII 13)S4—Line-feed character (ASCII10)S5—Backspace character (ASCII08)S6—Wait time before blind dialingS7—Wait time for carrier/dial toneS8—Pause duration (effected by comma)S9—Carrier detect response timeS10—Delay: Lost carrier until hangup timeS11—DTMF tone durationS12—Escape-sequence guard timeS25—DTR detection

When the &W command is usedto save a configuration profile,stored phone numbers are notsaved as part of the profile.

&Z—STORE TELEPHONENUMBER. The &Z command isused to store a telephone numberthat can be subsequently dialed

using the DS (dial stored number)command. The syntax is &Zm=n,where m specifies the memorylocation where the phone numberor dial string will be stored and n isthe number or dial string to bestored. For example, AT &Z5=T1(301) 555-1212 will store thespecified number at memorylocation 5. Ten memory locationsare available: 0-9.

(The &Z command is also usedto store passwords, as explained inSection 4, Security Operation.)

For pulse dialing, digits 0through 9 can be stored; for tonedialing, 0 through 9, A through D,# and * can be stored. The dialcommand modifiers listed in theCommand Guidelines section canalso be stored.

Each memory location can hold amaximum of 24 digits, althoughlocations 1 through 9 willautomatically expand to the nextempty location if loaded with morethan 24 digits. Even if a storednumber is continued to anotherlocation, the maximum length is 36characters. (Attempting to dial adial string of more than 36characters will result in an ERRORmessage.) A memory locationcannot be used for storage unless itis empty. To delete an entry, enterAT&Zm=, where m is the memorylocation number. Only location 0can be accessed from the modem’sfront panel (via the PHONE LCDscreen).

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\S—VIEW STATUS OF V.42-RELATED CONFIGURATION.The \S command displays the activeV.42 error correctionconfiguration, stored V.42 profiles,and certain other data notdisplayed by the &V command.

5.5 RegistersThe modem includes 28 registers(S0-S27) that can be used tocontrol specific modem operationsin Hayes mode only. Each registerholds a value that serves as aspecific operating instruction forthe modem. Several of the Sregisters affect how the previouslydescribed commands will beexecuted.

The functions of the registersintended for user access areexplained below and summarizedin Table 5-3.

5.5.1 READING AND SETTING REGISTERS

Use the S command to read thevalue of a register or to change itsvalue.

To read the current value of aregister, use the command S?,where the number of the register isspecified between the S and the ?,as follows: S9?. The decimal valueof the register contents will then bedisplayed. Multiple registers may beread. For example, if you wish toread the current value in registersS0 and S7, enter

AT S0? S7?

A typical response might be001,030, OK, meaning that thevalues stored in registers S0 and S7are 1 and 30, respectively.

To set or change a parameter, usethe command S=, where thenumber of the register follows Sand a value between 0 and 255 (therange of values that can be assignedto the registers) follows the equalsign:

AT S0=5

This command will change thevalue stored in S0 to 5.

The S command can also be usedwithout ? or = to point to a registerthat will be subsequently read fromor written to without beingspecified. To illustrate this, if youenter

AT S7

a pointer is set to the address ofregister S7. As long as no other Scommand is entered, the registervalue can be requested at any timewithout specifying the number. Ifyou enter AT? the modem displaysthe current value in the S7 register.Similarly, if you enter AT=8 themodem will change the value in the S7 register to 8.

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MODEM 32144

5.5.2 S REGISTER FUNCTIONS

This section describes the functionof individual S registers. Table 5-3 lists the range of possibleparameters and the default valuefor each S register. Only S registersthat are intended for user accessare listed.

S0—RING TO ANSWER ON.The value in this registerdetermines on what ring (first,second, third, etc.) the modem willanswer on. Setting S0 to 0 disablesauto-answer.

S1—RING COUNT. Register S1counts the number of ring signalsfor each incoming call. If morethan 8 seconds have passed sincethe last ring, S1 is cleared to zero.

S2—ESCAPE CODECHARACTER. The escape code iseffective for asynchronousoperation only. Values greater than127 will completely disable escapecode detection and prevent youfrom issuing a hangup command.

S3—CARRIAGE RETURN.Register S3 is effective forasynchronous operation only.Normally, the ASCII carriagereturn value, 13, is used.

S4—LINE FEED. This register is effective for asynchronousoperation only. The line-feedcharacter follows the carriage

return only when word result codeshave been selected (command V1).Line feed can be changed to a nullbut cannot be totally disabled.

S5—BACKSPACE. This register is effective for asynchronousoperation only. The value in S5defines the backspace character.Do not use values between 33 and126.

S6—BLIND DIALING WAITTIME. The value in S6 determineshow long the modem will wait afterpicking up the telephone line(going off-hook) before it begins todial. If S6 is set for less than 2seconds, the modem still waits 2seconds before dialing. If the X2 toX4 command is in effect, dial tonedetection will be enabled and blinddialing will be disabled, meaningthat the value in S6 will have noeffect.

S7—CARRIER/DIAL TONEWAIT TIME. This register controlstwo wait times—wait time forcarrier and, if W is included in thedial string, wait time for dial tone(or wait time for silence if @ isused).

S8—PAUSE TIME. The pausetime effected by a comma in a dialstring or other command line iscontrolled by register S8.

S9—CARRIER DETECTRESPONSE TIME. Register S9determines how long a carrier tonemust be present for the modem to

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recognize the tone and indicate acarrier detect. (The time requiredfor the absence of a carrier tone tobe recognized is fixed at 0.5second.)

S10—LOSS OF CARRIERDELAY. The value in register S10determines how long the delay willbe from the occurrence of a loss ofcarrier until the modem hangs upthe telephone line. A value of 255disables the modem’s carrierdisconnect option (and linecurrent option), meaning that themodem will not hang up in theabsence of carrier or line current.

S11—TONES. This register setsthe spacing of tones used fordialing. The rate can be slowed byincreasing the value of S11 to themaximum value, 255. This registerhas no effect on pulse dialing,which is fixed at 10 pulses persecond.

S12—GUARD TIME. Thisregister is effective forasynchronous operation only. Theescape guard time delay is requiredimmediately before and afterentering the escape code;therefore, the three escape-codecharacters must be entered withinthe guard time delay of each other.The unit for this register is 1/50second (or 20 ms), meaning thatthe default value of 50 equals 1second.

If the guard time is zero, timingwill not be a factor at all. The threeescape characters can occur with

any timing relationship, but theymust be consecutive. Be cautiouswhen assigning small guard times,however. You may not be able toenter three characters fast enough,especially if the guard time is lessthan the time required to transmitone character at the currenttransmission rate.

S18—DIAGNOSTIC TIMER. Thevalue in register S18 determineshow long a diagnostic test will run.For example, if S18 is set to 120,the test (activated by one of the &Tcommands) will run for 120seconds. If S18 is set to zero, thedefault, the test timer will bedisabled and the test will runindefinitely. To terminate a testwhen the test timer is disabled, usethe command &T0 or reset themodem. Register S18 is set to zeroon powerup or by the commandAT Z or AT S18=0.

S25—DELAY TO DTR. Theeffect of the value stored in registerS25 is dependent on the operatingmode, as explained below.

Synchronous mode 1: A delayoccurs after a call is establishedbefore the modem examines thestate of DTR. The duration of thisdelay is the value specified in S25(in seconds). This allows theoperator time to disconnect themodem from an asynchronous dataterminal and attach it to asynchronous terminal withoutforcing the modem back into thecommand state.

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MODEM 32144

Synchronous modes 1, 2, and 3:

A change in DTR (ON or OFF)which lasts for less than the value in register S25 (in 1/100ths of asecond) is ignored by the modem.

S26—RTS TO CTS DELAYINTERVAL. This register affectssynchronous operation only. Withthe command &R0 in effect, CTS isturned on in response to an OFF-to-ON transition of RTS from thelocal DTE—after the delayspecified by the value in registerS26 (but only if the modem is on-line and ready to receivesynchronous data).

5.6 Saving Option SelectionsChanges made to option settingswill cease to be effective if power isremoved from the modem or if afactory reset has occurred—unlessthe modem configuration (alloption settings) is saved tononvolatile memory. The storableparameters of the modem’sconfiguration can be saved to userprofile 0 or 1 using the &Wcommand (&W0 or &W1). Uponpowerup, the modem will recalleither profile 0 or profile 1,depending on which has beendesignated as the default profile.(The modem is shipped from thefactory with profile 0 as the defaultprofile.)

As explained in the followingsections, the modem isprogrammed to treat profile 0 and

profile 1 differently. Use profile 0for your standard configurationand make it the default profile(&Y0). Profile 1 (optional) isintended to be used to store analternate configuration (e.g., foran alternate application).

To view the contents of the user profiles, use the &V and \Scommands.

User Profile 0

User profile 0 is linked to themodem’s front panel (i.e.,selections made using the front-panel LCD).

• If you make option changesusing the front panel, thechanges for options for whichthere are associated Hayescommands will be saved toprofile 0 when you exit theSETUP menu.

• If profile 0 is recalled as theactive configuration, the LCDscreens will reflect the profile 0configuration.

• If profile 0 is changed by meansof Hayes commands or via theSummary Setup feature andthen saved, the changes madewill be reflected on the LCDand will be effective for allmodes.

If you make option changes fromthe front panel but have not exitedthe SETUP menu, and then makeoption changes using Hayes

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commands and save them toprofile 0 using the &W command,the changes made using Hayescommands and saved to profile 0will override the front-panelselections.

A Quick Setup will overwritemost modem option settings.However, certain option settingsstored in user profile 0 are notaltered by Quick Setup—unless youchange the configuration from oneQuick Setup type to another. Thefollowing parameters in userprofile 0 are not affected by aQuick Setup of the same type:Option settings set by the Hayescompatible commands E, F, Q, V,X, &J, &L, &P, &M, &Q, &Z, and\V; and S register values in registersS18, S25, and S26. A factory resetwill reset these parameters—and allothers—to the factory-defaultsettings.

User Profile 1

User profile 1 is not linked to thefront panel.

• Option changes made from thefront panel are not saved toprofile 1. Profile 1 can bechanged only by using Hayescommands or the SummarySetup feature.

• If profile 1 is recalled as theactive configuration, the LCDscreens will not be affected.(This means that when profile1 is active, it is possible for the

LCD to display an optionsetting that does not reflect thesetting currently in effect.)

• If profile 1 is changed by meansof Hayes commands or via theSummary Setup feature, thechanges will not be reflected onthe LCD and will only affectHayes mode operation.

If profile 1 is being used as theactive configuration, the optionsmarked with an asterisk (*) inTable 5-1 should be controlled byusing the AT commands listed inTable 5-1 or by using the Summary Setupfeature described in Appendix B.When profile 1 is active, theseoptions can be changed via thefront panel LCD, but the changeswill not be effective for Hayes modeoperation. (However, if profile 0 issubsequently recalled as the activeconfiguration, the changes will beeffective at that time.)

5.7 Facsimile (Fax) TransmissionFax operation is available in Hayesmode only. The modem supportsfax classes 1 and 2. You can useyour modem with a fax program totransmit and receive facsimile data.

5.8 Hayes Mode Reference TablesTable 5-1 lists the Hayes compatiblecommands that can be used withthe modem.

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MODEM 32144

Table 5-1. Hayes Compatible Commands

Command Function/Explanation

A ANSWER No parameters.

A/ REPEAT PREVIOUS COMMAND. No

parameters.

B BELL/CCITT COMPATIBILITY MODE*

B0 Selects CCITT V.22 mode (2100 Hz).

B1 Selects Bell 212A mode (2225 Hz).

C1 Modem displays OK; command has no other

effect. (This response—instead of ERROR—

maintains a degree of compatibility with older

modems that support this command.)

D ORIGINATE MODE FOR DIALING. No

parameters.

DS DIAL STORED NUMBER. Parameters are

0-9 (available memory locations).

E ECHO

E0 No echo.

E1 Echoes all characters back to terminal screen

when using a full duplex terminal and in local

command mode.

F1 Modem displays OK. Command has no other

effect—unless V.22bis/V.22/V.21/V.23 fallback

operation has been enabled. (For details, see

Automatic Fallback in Chapter 4.)

H TELEPHONE SWITCH HOOK

H0 On-hook (hang up).

H1 or H2 Off-hook.

Default settings (where applicable) are in bold face.

*If user profile is active, option can be controlled (for Hayes mode operation)

only by given command or by using Summary Setup. Do not change via

front panel (except via Summary Setup).

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Table 5-1. Hayes Compatible Commands (continued)


I PRODUCT CODE OR CHECKSUM

I0 Requests product code.

I1 Requests checksum for the modem’s software.

(Only a portion of the checksum displayed via

the front panel will be displayed, in decimal

format.)

I2 Requests verification of software checksum.

I3 Requests the following for each EPROM

(programmable memory unit): chip, part and

revision number; checksum.

I4 Reserved.

L SPEAKER VOLUME*

L0 or L1 Low speaker volume.

L2 Medium volume.

L3 High volume.

M SPEAKER CONTROL*

M0 Speaker always OFF.

M1 Speaker ON until carrier is detected.

M2 Speaker always ON.

M3 Speaker OFF during dialing; otherwise ON

until carrier is detected.

O FORCED ON-LINE. Forces modem to on-line

state.

P PULSE DIAL. No parameters, but the default

is T (for tone dial).

Q SEND RESULT CODE

Q0 Send result codes.

Q1 Withhold result codes (quiet).

Q2 Withhold result codes for incoming calls only

(quiet answer).

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MODEM 32144



Sn=v MODIFY S REGISTER. n is the register to be

modified; v is the value to be written.

Sn? READ S REGISTER. n is the register to be

read.

T TONE DIAL. No parameters.

V WORD/DIGIT RESULT CODE

V0 Result codes are transmitted as digits.

V1 Result codes are transmitted as words.

W WAIT FOR DIAL TONE No parameters, but

default wait time (register S7) is 30 seconds.

X SELECT RESULT CODE

X0 Selects basic result codes, 0-4.

Modem will blind dial (without dial tone).

X1 No speed indication; no busy or dial tone detect.

X2 Selects result codes 0-6, 10, 11, 13, 14, 15, and

18.

X3 Same as X1 except busy signal detect is

enabled. Selects result codes 0-5, 7, 10, 11,

13, 14, 15, and 18.

X4 Same as X1 except busy signal detect is

enabled. Selects all result codes. Connection

speed (up to 14,400 bps) indicated; busy

signal and dial tone detect enabled.

Note: Result code 8 is independent of the X

command; it is displayed only when the @ dial

modifier is used.

Y LONG SPACE DISCONNECT*

Y0 Disables long space disconnect.

Y1 Enables long space disconnect.

Z RECALL STORED USER PROFILE

115




Z0 Resets modem and recalls stored user profile 0.

Z1 Resets modem and recalls stored user profile 1.

, (comma) PAUSE. No parameters, but default pause time

(in register S8) is 2 seconds.

; (semicolon) FORCED COMMAND STATE. No parameters.

@ WAIT FOR SILENCE BEFORE DIALING. No

parameters, but default wait time (register S7) is

30 seconds.

! (exclamation) INITIATE FLASH HOOK. No parameters.

&C DATA CARRIER DETECT CONTROL*

&C0 DCD always ON when DTR is present.

&C1 DCD ON only in the presence of suitable data.

&C2 DCD ON when DTR is present; then toggles off

for 500 ms upon disconnect.

&D DATA TERMINAL READY CONTROL*

&D0 Ignore DTR.

&D1 Go on-hook, assume command state and

disable auto-answer upon DTR loss.

&D2 Disconnect upon DTR loss.

&D3 Reinitialize upon DTR loss.

&F RECALL FACTORY CONFIGURATION

No parameters.

&G GUARD TONE CONTROL*

&G0 Guard tone disabled.

&G1 Enables 550-Hz guard tone.

&G2 Enables 1800-Hz guard tone.

&J Modem displays OK result code; command has

no other effect. (The modem is configured for

A/A1 control or MI/MIC control via jumpers JP2

and JP3, as detailed in Appendix C.)

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MODEM 32144



&L Modem displays OK result code; command has

no other effect. (The modem is configured for

leased line or dialup line operation via the

front-panel QUICK SETUP and/or LINE TYPE

screens.)

&M Can be substituted for &Q.

&P Modem displays OK result code; command has

no other effect. (The pulse dialing ratio is

factory-set, depending on whether the modem

is a US or international model.)

&Q ASYNCHRONOUS/SYNCHRONOUS MODE

&Q0 Asynchronous mode.

&Q1 Synchronous mode 1—

Synchronous/asynchronous mode.

&Q2 Synchronous mode 2—OFF-to-ON DTR

causes the modem to automatically dial a

stored number.

&Q3 Synchronous mode 3—Synchronous mode with

manual dial. (A manually dialed call will switch

immediately to synchronous mode.)

&R RTS AND CTS OPTIONS*

&R0 CTS follows RTS.

&R1 CTS follows DTR from the DTE.

&R2 CTS is on while the modem is on-line.

&S DATA SET READY CONTROL*

&S0 DSR always on.

&S1 DSR operates on according to RS-232

specification.

&S2 Options DSR operation for a crossover

connection.

117




&T TEST COMMANDS

&T0 Terminates a test in progress.

&T0 must be the last command in a command

line.

&T1 Initiates a local analog loopback test.

&T3 Initiates a local digital loopback test.

&T4 Allows the local modem to accept a request

from the remote modem for a remote digital

loopback test.

&T5 Prevents the modem from accepting a request

from the remote modem for a remote digital

loopback test self-test.

&T6 Initiates a remote digital loopback test.

&T7 Initiates a remote digital loopback test self-test.

&T8 Initiates a local analog loopback self-test.

&V VIEW ACTIVE CONFIGURATION, ETC.

&V0 Displays modem configuration, user profiles,

and phone numbers stored in memory

locations 0-5.

&V1 Displays all stored phone numbers (contents

of memory locations 0-9).

&W WRITE PROFILE TO MEMORY

&W0 Saves storable configuration parameters as

user profile 0.

&W1 Saves storable configuration parameters as

user profile 1.

&X TRANSMITTER CLOCKING*

&X0 Selects internal clocking.

&X1 Selects external clocking.

&X2 Selects receive-mode (slaved) clocking.

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MODEM 32144



&Y DEFAULT USER PROFILE

&Y0 Stored user profile 1 will be recalled on powerup.

&Y1 Stored user profile 1 will be recalled on powerup.

&Z STORE TELEPHONE NUMBER. Parameters

0-9 (available memory locations).

\A KEYBOARD ABORT (answer unit only)

\A0 Enables keyboard abort. When keyboard

abort is enabled, pressing any key on the

answer unit will abort handshaking (and

thereby prevent a connection from being

made).

\A1 Disables keyboard abort.

\B BUFFER MODE/SPEED CONVERSION*1

\B0 Disables speed conversion.

\B1 Enables speed conversion

\C MNP CLASS (LIMIT)*1

\C1 Limits operation to MNP class 1.

\C2 Limits operation to MNP classes 1 and 2.

\C3 Limits operation to MNP classes 1 through 3.



\D DIALING MESSAGE

\D0 Disables ”DIALING” message.

\D1 Enables “DIALING” message.

\F MNP FLYBACK BUFFER*1

\F0 Enables flyback buffer.

\F1 Disables flyback buffer.

\K V.42 BREAK HANDLING*1

\K0 Selects normal break handling.

\K1 Selects destructive/expedited break handling.

119


Table 5-1. Hayes-Compatible Commands (continued)


\K2 Selects non-destructive/expedited break

handling.

\K3 Selects non-destructive/non-expedited break

handling.

\M V.42 bis OPERATION*1

\M0 Enables V.42bis operation (error correction

with data compression).

\M1 Disables V.42bis operation.

\N V.42 MODE*1

\N0 Disables error correction.

\N1 Enables mandatory mode for error correction.

\N2 Disables error correction.

\N3 Enables automatic mode for error correction.

1Option can be changed only when the modem is disconnected from the

phone line.

\P V.42 PROTOCOL*1

\P0 Selects LAPM protocol only.

\P1 Selects MNP protocol only.

\P2 Selects LAPM/MNP protocol (MNP as alternate).

\Q V.42 FLOW CONTROL*1

Two parameters may be used (e.g., \Q0,1;

\Q3,2, etc.).

First parameter specifies DCE-DTE flow;

second (optional) specifies DTE-DCE flow

control.

0 None (no flow control).

120

MODEM 32144

Table 5-1. Hayes-Compatible Commands (continued)NOTE: DTE speed and parity are set automatically. Auto-answer is enabled or

disabled by S register S0.


1 CTS on/off or RTS on/off (CTS for DCE-DTE

flow control, RTS for DTE-DCE).

2 DC1/DC2 flow control.

3 DC1/DC3 flow control (default for DCE-DTE

and DTE-DCE).

%E0 Disables auto-retrain.

%E1 Enables auto-retrain.

-L0 Selects permissive transmit level.

-L1 Selects programmable transmit level.

\S VIEW STATUS OF V.42-RELATED

CONFIGURATION. No parameters.

\T LOAD INACTIVITY TIMER

\T0 Disables inactivity timer.

\Tn Sets inactivity timer to n minutes (where n=0

to 60).

\V V.42 RESULT CODES1

\V0 Activates regular V.42 result codes.

\V1 Activates extended V.42 result codes.

%V0 Switches from Hayes mode to V.25bis mode,

asynchronous.

%V1 Switches to V.25bis mode, sync bit oriented

(HDLC).

%V2 Switches to V.25bis mode, synchronous

character oriented.

\X V.42 PASS-THROUGH FLOW CONTROL*1

\X0 Enables pass-through flow control.

\X1 Disables pass-through flow control.

121


Table 5-2. Hayes Mode Result Codes

Digit code Word code Meaning

0 OK Command line executed without errors

1 CONNECT Carrier detected at 0-300, 1200, or

2400 bps (basic code set)

2 RING Ringing signal detected (in answer

mode). (When the modem detects

a ring, it sends a RING result code

unless it is in the process of accepting

a command. However, the modem

will answer the call only if it is set for

automatic answer or is given an A

command.)

3 NO CARRIER Carrier lost or never detected.

4 ERROR Error in command line, invalid

command, command line exceeds 40

characters, or invalid character format.

5 CONNECT 1200 Carrier detected at 1200 bps.

6 NO DIALTONE No dial tone detected.

7 BUSY Busy signal detected.

8 NO ANSWER No period of silence detected. This

code will appear only if @ (“wait for

silence before dialing”) has been

included in the dial string.

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MODEM 32144

Table 5-2. Hayes Mode Result Codes (continued)

Digit code Word code Meaning



11 CONNECT 1275 Modem is on-line in V.23 mode

(1200/75 bps).


13 CONNECT 12.0 Carrier detected at 12,000 bps.

14 CONNECT 14.4 Carrier detected at 14,400 bps.



20 LINKING Modem is dialing numbers that’ve been

linked using the L (link) dial modifier.

21 CONNECT 16.8 Carrier detected at 16.8 Kbps.


72 DIALING Modem is dialing.





NOTE: Four additional word codes are “BUFFER,” “MNP,” “V42” and “V42bis”

followed by the DTE interface speed. These codes indicate if the modem is in

buffer, MNP, or LAPM (V.42/V.42 bis) mode. The corresponding digit codes and

speeds they indicate are listed on the next page (with all speeds in bits per

second).

123


Table 5-2. Hayes Mode Result Codes (continued)

BUFFER MNP V42 V42bis

28-19200 36-19200 44-19200 55-38400

29-9600 37-9600 45-9600 56-19200

30-4800 38-4800 46-4800 57-9600

31-2400 39-2400 47-2400 58-4800

32-1200 40-1200 48-1200 59-2400

33-600 41-600 49-600 60-1200

34-300 42-300 50-300 61-600

35-110 43-100 51-110 62-300

53-38400 54-38400 52-38400 63-110

64-57600 65-57600 66-57600 67-57600

68-1800 69-1800 70-1800 71-1800

77-115200 78-115200 79-115200 80-115200

82-230400 83-230400 84-230400 85-230400

124

MODEM 32144

Table 5-3. S Register Functions (only registers intended for useraccess are listed)

Register Range Units Default Description

S0 0-255 rings 1 Ring to answer on

S1 0-255 rings 0 Counts the number of

rings

S2 0-127 ASCII 43 Escape code character

S3 0-127 ASCII 13 Carriage return character

S4 0-127 ASCII 10 Line feed character

S5 0-127 ASCII 8 Backspace character

125



S6 2-255 sec 2 Wait time before blind

dialing

S7 1-60 sec 30 Wait time for carrier or

dial tone

S8 0-255 sec 2 Pause time for comma

S9 1-255 sec 6 Carrier detect response

time

S10 1-255 1/10 sec 14 Delay time between

loss of carrier and

“hang-up”

126

MODEM 32144


Register Range Units Default Description

S11 70-255 ms 70 Tone spacing

S12 0-255 1/50 sec 50 Escape code guard time

S18 0-255 sec 0 Test timer

S25 0-255 sec or 5 Delay to DTR

1/100 sec1

S26 0-255 1/100 sec 0 RTS-to-CTS delay

(half duplex)

S43 Speed limit, maximum

S44 Speed limit, minimum

S46 CD level

S53 0-15 -dBm 0 Leased line transmit level

S61 DTE speed

1Depends on mode; see previous section, S25—Delay to DTR.

75

CHAPTER 4: General Operation and Special Features

The number stored via thePHONE screen is stored in phonecell 0 (zero). To autodial the front-panel phone number in Hayes orV.25bis mode, specify phone cell 0.

4.2.2 HOW TO STORE A PHONENUMBER

To store a phone number using themodem’s front panel controls,select PHONE from MODEMSETUPS screen 5. The followingscreen will be displayed:

• Use the right and left arrowpushbuttons to go to theposition on the LCD where youwant to enter or change anumber or character. Thenumber or character at thecurrent cursor location flasheson and off.

• Use pushbutton 1 to decrease anumber at the current cursorlocation or pushbutton 3 toincrease a number.

• Use pushbutton 2 (CTRL) tocycle through the dialingcontrol characters. The dialingcontrol characters are listed inTable 4-1, in the order in whichthey appear on the LCD if youcycle through them. Dialingcontrol characters can be savedwith a phone number toperform the functions listed inTable 4-1 when the number isdialed.

The phone number is savedwhen you return to the MAINMENU.

- - - - - - - - - - - - - - - - - - - - - - - - - - - -DEC CTRL INC

If a number has been previouslystored, the number will bedisplayed on the top line of theLCD (instead of dashes, as shownabove). Only one phone number—24 characters maximum—can bestored via the front panel.

Enter the number to be stored byusing the front-panel pushbuttonsas follows:

76

MODEM 32144

Table 4-1. Dialing Control Characters(for use with front-panel PHONE screen)

Character Function

(space) Used only for clarity.

(comma) Effects 2-second pause.

W (or colon) Wait 30 seconds for dial tone before

proceeding.

P Sets pulse dialing mode.

T Sets tone dialing mode.

* Dial * (tone dialing only).

# Dial # (tone dialing only).

/ (diagonal) Prefix required for use with R (/R).

A-D Used in some PBX applications (tone dialing

only).

R Configures modem for Dial Line Auto-

Recovery. Requires / prefix. See Dial Line

Auto-Recovery section later in this chapter.

. (period) Marks end of phone number.

L Links a phone number to another number to

be dialed as an alternate. See L—LINK in

Section 5.4.

: (colon, or W) Wait 30 seconds for dial tone before

proceeding.

- (dash) Used only for clarity (no function).

NOTES: A, B, C, and D are used in some private branch exchange (PBX)

applications. The * and # symbols are sometimes used for access to remote

computer systems.

77


4.3 Automatic FallbackThe modem incorporates threeautomatic fallback features that canbe controlled by the user:

• Operating-Mode Fallback—Provides compatibility withmodes that use any of severaldifferent operating modes.

• Two options for automatic datarate adjustment: RateRenegotiation Procedure(RRP) and Speed Fallback—These features allow themodem to automatically selectthe highest possible data rate,depending on the signalquality.

4.3.1 OPERATING-MODE FALLBACK

This section applies to dial-lineoperation only.

When the modem originates oranswers a call, it determines fromthe “handshake” routine with theother modem the most efficientoperating mode that is supportedby the other modem andautomatically “falls back” to thatmode. The modem supports twoalternatives for operating-modefallback: V.22 bis/Bell 212A/Bell103 fallback operation (defaultsetting) and V.22bis/V.22/V.21/V.23 fallbackoperation. Operating-modefallback functions when themodem is in either manual orautomatic originate mode ormanual or automatic answer mode.

For communication within theUnited States, use the defaultsetting for Operating-ModeFallback—V.22bis/Bell 212A/Bell103.

V.22 bis/V.22/V.21/V.23 FallbackOperation

To configure the modem for V.22bis/V.22/V.21/V.23 fallbackoperation, refer to Appendix B,Fig. B-7. Change the OperatingMode Fallback parameter shown inthe diagram from 0 (the factorysetting) to 1. (This is the only waythe Operating Mode Fallbacksetting can be changed.)

Changing the Operating ModeFallback parameter to 1 has thefollowing effects:

• The modem will be configuredfor V.22 bis 2400-bps/V.221200- and 600-bps/V.21 300-bps/V.23 1200/75 bps fallbackoperation. As a result, 600 and1200/75 bps will appear asadditional selections on theSPEED LIMIT LCD screens.

• Fallback to V.22 bis Bell 212Aand Bell 103 compatibility isdisabled.

• An AT command is available (inHayes mode only) that allowscontrol over operating mode asfollows: F0—Multi-modeoperation (default); F1—V.21,300 bps; F2—V.22, 600 bps;F3—V.23, 1200/75 bps; F4—

78

MODEM 32144

V.22, 1200 bps; F5—V.22bis,2400 bps; F6—V.32 (highestcommon speed). Except formulti-mode operation, themode and speed are limited tothe mode and speed specified.Multi-mode operation allowsthe modem to automatically fallback to the most efficient modethat can be used by bothmodems.

Available Fallback Modes

The preferred mode is V.32/V.32bis (4800 bps or higher,asynchronous/synchronous, fullduplex); however, if the othermodem does not support V.32 orV.32 bis, the modem will fall backto one of the modes listed below.The fallback modes are listed in theorder in which they are attemptedby the modem in normaloperation:

Table 4-2. V.22 bis/Bell 212A/Bell 103 Fallback (Default)

Mode Description

V.22 bis 2400 bps asynchronous/synchronous

Bell 212A 1200 bps asynchronous/synchronous

Bell 103 0-300 bps asynchronous

All modes are full duplex.

If V.22 bis/V.22/V.21/V.23fallback operation is enabled, thefollowing fallback modes areavailable. As in the previous list, themodes are listed in the order inwhich they are attempted by themodem.

79


Table 4-3. V.22 bis/V.22/V.21/V.23 Fallback

Mode Description

V.22 bis 2400 bps asynchronous/synchronous

V.22 1200 and 600 bps asynchronous/synchronous

V.21 300 bps asynchronous

V.23 1200/75 bps asynchronous

All modes are full duplex.

the minimum and maximum ratesettings of the Speed Limit option.If satisfactory performance cannotbe attained at any of the availabledata rates, the modem will initiate aGSTN cleardown (line disconnect).If the originate modem attempts tonegotiate a rate that is lower thanthe minimum rate setting of theanswer modem, the answer modemwill initiate a GSTN cleardown.

RRP will function only if SpeedFallback is enabled (factorydefault) and if the V.32 Modeoption is set to V.32 bis (factorydefault). (Both are Summary Setupoptions.)

The factory default setting forRRP is enabled. To change the RRPoption, refer to Appendix B, Fig. B-7. Change the Rate RegenerationProcedure (RRP) parameter shownin the diagram to 0 (disable) or 1(enable). (This is the only way theRRP option can be changed.)

The operating mode can becontrolled by the user through theSPEED LIMIT screens on the LCDin all modes except Hayes mode.See Chapter 3 for details.

NOTEIf you want to select 1200/75bps for both the maximumand minimum rate, V.22bis/V.22/V.21/V.23 fallbackmust also be selected.

4.3.2 AUTOMATIC RATE ADJUSTMENT

Both sections below apply to bothdial line and leased line operation.

Rate Renegotiation Procedure (RRP)

If Rate Renegotiation Procedure(RRP) is enabled, the modem willautomatically fall back or fallforward to a lower or higher datarate at any time during datatransmission (without retraining)in response to changes in signalquality. Data rate adjustments arelimited to the range of 4800 to14,400 bps and are also limited by

80

MODEM 32144

4.4 Dumb Mode and Bell 208OperationTable 4-3 lists dialing parametersthat may be used to modify Dumbmode or Bell 208 dialingoperations.

4.4.1 MANUAL ORIGINATE/ANSWEROPERATION

When the modem is operating inDumb mode or configured for Bell208 operation, data calls may bemanually originated from a phoneset. (Plug the phone into themodem jack marked “PHONE.”)

For manual-originate operation,the remote modem may beconfigured for either automatic ormanual answer. For manual-originate/answer operation, onemodem must be set to ANSWERand one must be set toORIGINATE via the ANS/ORGDEFAULT screen. For either typeof operation, use the Quick Setupto configure the modem. (TheDumb mode Quick Setup defaultsto asynchronous operation; the Bell208 and V.32/208 Quick Setupsdefault to synchronous operation.)

Any of these three Quick Setupswill set the modem to originatemode. If you want to set yourmodem to answer mode, use thefront panel controls to access theANS/ORG DEFAULT screen(MODEM SETUPS screen 4). Thenselect ANSWER (answer mode).

Originating a Data Call Manually

To manually originate a data call,select TALK from MAIN MENUscreen 1. The MANUAL-DIALscreen will now be displayed. SelectTALK again. This puts the modemin talk mode. Lift the handset andlisten for the dial tone. Dial thephone number of the remotemodem.

When you hear a high-pitchedanswer tone, select DATA from theMANUAL-DIAL screen, and placethe handset back on the cradle.The LCD will display the status ofthe communication. Typically it willappear as follows:

D TR MR RS CS9600 CD

The data link between the twomodems is now established, anddata transfer can begin.

81


Answering a Data Call Manually

An incoming call may be answeredmanually or automatically,although to answer a data callmanually, the Auto-Answer optionmust be disabled. Before the call isreceived, the modem must be set toTALK, as explained in the previoussection. The unit that will beswitched to DATA mode first mustbe set for answer mode (using theanswer/originate option). Theother unit must be set for originatemode.

NOTEIf you set the modem to talkmode, the phone will ring,but the modem will notanswer, even if the Auto-Answer option is enabled.

After the phone has rung, andyou have answered it, the modemmust be set for data mode: Withthe MANUAL-DIAL screen stilldisplayed, select DATA. This putsthe modem in data mode.

The first person to go to datamode will hear his telephonedisconnect as his modem connects.The other person must wait untilhe hears an answer tone, and thenswitch to data mode (select DATA).When both modems are in datamode, the data communication willbegin. The LCD will display thestatus of the connection.

Terminating a Data Call

There are several ways a data callcan be terminated. One way isthrough communicationsoftware—by following the softwaremanufacturer’s instructions. Analternate method is to switch to theTALK option (talk mode) on theMANUAL-DIAL screen, asdescribed in the previous section.Another method is to drop theDTR signal from the DTE (bysoftware control or by turning theDTE off).

4.5 V.32/208 Auto-Detect ModeWhen V.32/208 auto-detect modeis enabled, the modem willautomatically select either V.32(V.32/V.32 bis) or Bell 208operation. These two types ofoperation are described below.

4.5.1 V.32/V.32 BIS OPERATION

In V.32/208 auto-detect mode, ananswering modem will, upondetection of a V.32 handshake,operate with the following optionsset as shown:

• Data format—synchronous

• V.13 operation—TX and RX

• Carrier type—constant

• CTS to EIA—RTS (CTS followsRTS)

82

MODEM 32144

4.5.2 BELL 208 OPERATION

In V.32/208 auto-detect mode, ananswering modem will, upondetection of an originating Bell208B modem, operate with thefollowing options set as shown:

• Data format—synchronous

• V.13 operation—off

• Carrier type—switched

The originating Bell 208 modemmust be configured to detect theBell 208 answer tone before it goesto data mode. (Some 208 modemsmay not have this option.)

4.5.3 AUTOMATIC FALLBACK

When the modem is configured forV.32/208 auto-select mode and inanswer mode, it will not handshakein V.22 bis, Bell 212/103 orV.21/V.22, V.23 mode.

4.6 V.13 OperationThe modem can be configured forCCITT V.13 operation (whichemulates half duplex operation)for either point-to-point ormultidrop applications. (Thecorrect options for theseapplications are identified inChapter 3.) The modem normallyoperates in full duplex; however,some applications (such as certainnetwork environments) mayrequire control of a remote CDsignal by a local Request to Send(RTS) signal. V.13 operation allows

local RTS control of a remote CDsignal without actual ON-OFFswitching of the modem carrier.

The following explains how themodem will respond to RTS signalswhen it is configured for V.13operation:

When RTS is raised high by theterminal, the V.13 ON PATTERNwill be sent. The modem will thenraise CTS (and data can be sent).When RTS is brought low, the V.13IDLE PATTERN will be sent, andthe modem will drop CTS. (If V.13TX is enabled but the modem datapump is not ready to send, forexample, if it is training orretraining, raising RTS will causeCTS to be raised, but the V.13 ONPATTERN will not be sent.) WhenV.13 RX is enabled, CD will turnON if the V.13 ON PATTERN isdetected; CD will turn OFF if theV.13 IDLE PATTERN is detected orif the modem retrains, loses carrier,or is reset.

4.7 DTR Dialing

NOTETo use DTR dialing in V.25bis or Penril mode, you mustuse the Summary Setupfeature, as explained inChapters 6 (V.25 bis) and 7(Penril).

83


4.7.1 DIALING A STORED NUMBER

DTR dialing allows you to set upthe modem to automatically dial astored number even when theautodialer has not been enabled.

To enable DTR dialing, selectDTR from the DIALER optionscreen.

When DTR dialing is enabled, anOFF-to-ON transition of DTR willcause the modem to automaticallydial the number previously storedusing the front panel LCD. DTRmust remain on for at least 50 msto effect automatic dialing. A 50-msdrop of DTR will abort the processor disconnect the call. When DTRgoes high again for at least 50 ms,the automatic dialing process willbegin again.

4.7.2 ANSWER MODE OPERATION

If the modem is set for DTRdialing, it will automatically answerwithout DTR. However, it will notbe able to transfer data until DTRgoes high. The call may beterminated by dropping DTR.

4.8 Dial Line Auto-RecoveryThe Dial Line Auto-Recoveryfeature allows you to setup themodem for a dial-up application soit will automatically redial torestore a broken connection if themodem goes on-hook. In this way,the Dial Line Auto-Recoveryfeature emulates the reliability of aleased line connection.

4.8.1 SETTING UP THE MODEM FORDIAL LINE AUTO-RECOVERY

Two steps are required to set up themodem for Dial Line Auto-Recovery: You must first enter orstore the number to be dialedtogether with the /R command;then you must enable Dial LineAuto-Recovery.

Entering the /R Command

To configure the modem for DialLine Auto-Recovery from the frontpanel, enter the phone number tobe dialed followed by /R (the DialLine Auto-Recovery command) onthe PHONE screen:

T555-4545/RDEC CTRL INC

If you need assistance, seeSection 4.2, Storing PhoneNumbers.

An alternate way to configure themodem for Dial Line Auto-Recovery (in Hayes mode only) isto use the Hayes AT &Z commandto store the phone number to beredialed and the /R command inmemory location 0, by entering

AT &Z0=T555=4545/R

84

MODEM 32144

Enabling Dial Line Auto-Recovery

Dial Line Auto-Recovery will not beactive until you select DIAL fromthe front panel AUTO-DIAL screen(or, in Hayes mode, use thecommand AT DS=0—or, in V.25 bismode, use the command CRS 0). Ifpower is removed from themodem, you will have to re-enableDial Line Auto-Recovery. To disableDial Line Auto-Recovery, selectRESET from MAIN MENU screen3.

4.8.2 RECOVERY PROCEDURE

If Dial Line Auto-Recovery isenabled and the modem goes on-hook, it will redial the storedphone number up to 10 times. Itwill redial 5 times at 30-secondintervals, wait 2 hours, and thenredial 5 additional times at 30-second intervals. The modem stopsredialing after 10 attempts.

If a connection has been brokenand re-established and is thenbroken again, the full sequence of10 redial attempts will not occurunless the modem has been on-linefor more than 1 hour. The modemwill redial, but it is programmednot to exceed more than 10 redialattempts in 1 hour.

4.9 Leased Line Auto-RecoveryThe Leased Line Auto-Recoveryfeature allows the modem toautomatically restore operation fora leased line application by usingdial lines as a backup whenconditions on the leased linesdeteriorate. The modem usessignal quality and loss of carrierdetect to determine if lineconditions are unsatisfactory.Leased Line Auto-Recovery isaccessed via the AUTO-RECOVERYscreen on the front-panel LCD.

The following conditions arerequired for Leased Line Auto-Recovery operation:

• Leased Line Auto-Recoverymust be enabled (using theLeased Line Auto-RecoverySelect option) on bothcommunicating modems.

• The Leased Line Auto-RecoverySelect, Return, and Test optionsmust be set correctly on bothcommunicating modems, asexplained in the followingsections.

• A dial backup line (or lines)must be installed.

• The phone number to be dialed(the backup line) must bestored in the originate modem,as explained in the previoussection.

• Auto-answer must be enabledon the answer modem.

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4.9.1 AUTODIAL BACKUP

The modem will automatically dialthe stored number to connect overthe backup line if it detects poorsignal quality (ER) or a loss ofcarrier detect (CD) on the leasedline. The criteria used by themodem in assessing the conditionof the leased line depend upon thesettings of the Signal Qualityoption (one error in 103 or 105 bits)and the Carrier Detect Leveloption (-43, 33, or -26 dBm).

Dial Backup Message

When dial backup occurs (eitherautomatically or by operatorintervention), the followingmessage will flash on the frontpanel LCD of both modems:

4.9.2 EXIT FROM LEASED LINE AUTO-RECOVERY

If the Leased Line Auto-RecoveryReturn option is enabled (seebelow, the modem willautomatically exit the Auto-Recovery mode when the leasedline conditions are satisfactory. Anynormal disconnects (such as loss ofcarrier or line current) may alsodisconnect the dial connectionsand return communication to theleased line.

To ensure the proper disconnectcapabilities for Leased Line AutoRecovery mode, both of thefollowing disconnect options mustbe enabled on both modems: linecurrent disconnect (CURRENTDISC’T screen) and carrierdisconnect (CARRIER DISC’T).

To manually exit the Leased LineAuto-Recovery mode and return toleased-line operation, select DIALfrom MAIN MENU screen 1, andthen select HANGUP for theAUTO-DIAL screen.

ATTENTION:DIAL BACKUP

This message will clear when themodem returns to the leased line.If you want to clear the messagewhile the modem is still in dial-backup mode, press the ENTpushbutton.

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MODEM 32144

Manual Recovery

If both modems are set forMANUAL RECOVERY, theoriginate unit can be used toautodial the number stored via thePHONE screen without having tochange the LINE TYPE setting oneither unit. To autodial, access theAUTO-DIAL screen and selectDIAL. To return to the leased line,select HANGUP from the AUTO-DIAL screen.

Return from Leased Line Auto-Recovery(RETN)

This option determines the criteriafor exiting Leased Line Auto-Recovery mode.

“RETURN IF GOOD>(10, 40, 60,or 120)s” means the modem willautomatically exit the Leased LineAuto-Recovery mode when it testsand finds the leased line in goodcondition for more than the timeperiod specified (10, 40, 60, or 120s). If the Return option is set toOFF, the modem will stay in theAuto-Recovery mode indefinitely,unless you select HANGUP fromthe AUTO-DIAL screen or unless aloss of line current or other normaldisconnect occurs. Either event willreturn communication to theleased line.

NOTEThe Return option settingmust be the same on bothcommunicating units.

4.9.3 LEASED LINE AUTO-RECOVERYOPTIONS

Three options allow you to specifythe criteria the modem will use indetermining when to enter andexit the Leased Line Auto-Recoverymode:

Leased Line Auto-Recovery Select(Select)

This option determines the type ofLeased Line Auto-Recoverydesired. “DIAL IF BAD>(1, 2, 3, or4) min” or “DIAL IF BAD>30 s(seconds)” means dial backup willoccur if bad line conditions arepresent for the specified (selected)time period. To disable the LeasedLine Auto Recovery, select NOAUTO RECOVERY. A sixth option,Manual Recovery, is discussedbelow.

NOTEIf “DIAL IF BAD>(1, 2, 3, or 44) min (or 30 s)” is selected,the Select option settings ofthe answer and originateunits must be the same.

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• Manual-response passwordprotection (MPP). Remoteusers attempting to connect tothe modem are required toenter a password. Incomingcalls are accepted only if theuser enters a valid password.

4.11 Automatic Password Protection(APP)The modem can be configured fortwo types of APP:

• APP without callback—Themodem can be configured sothat each time it receives aconnect request from anothermodem, it automaticallyemploys a security handshakethat includes a user-assignedpassword. Connect requests willbe accepted only from modemsthat have been programmedwith the same password. APPwithout callback functions inany operating mode that usestrellis coding (normally 72, 090bps and above).

• APP with callback—This type ofpassword protection is the sameas described above, except thatthe answer modem connectswith the originating modem bycalling it back. The connectioncan only be made if bothmodems are preprogrammedwith the same password and ifthe answer modem ispreprogrammed with thenumber of the originatingmodem (the callback phonenumber). APP with callback isfor dialup applications only(synchronous orasynchronous).

Test Interval (Test)

If the Return option has beenenabled (10, 40, 60, or 120 s), theTest Interval selections control howfrequently the modem will test theleased line conditions to determineif exit from the Leased Line Auto-Recovery mode is desirable (basedon the criteria selected for returnfrom Auto-Recovery). The modemcan be set to test every 10, 20, 40,or 60 minutes.

NOTEThe Test option setting mustbe the same on both units.

4.10 Modem Security Operation

NOTESecurity features describedin this manual provide adeterrent to unauthorizedaccess. No communicationssystem can be madeperfectly secure.

Two types of security operationare available to screen incomingcalls:

• Automatic password protection(APP). Users do not have toenter a password, but bothmodems must be correctlyconfigured to exchange thesame password (as part of asecurity handshake), or theywill not be able to connect.

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MODEM 32144

With either type of APP, eachincoming call is password-protected, yet there is no need foruser to enter a password. Passwordsare preprogrammed, sent over themodems’ auxiliary channel, andautomatically compared by themodem. The only time manualintervention is required is when thepassword (and callback number, ifused) is established or changed.

If desired, the password can bedisabled. This allows the modem toaccept calls from modems that havenot been programmed to send thecorrect password—includingmodems that do not support themodem security handshake.

The automatically invokedpassword (and callback number, ifused) is established or changed.

If desired, the password can bedisabled. This allows the modem toaccept calls from modems that havenot been programmed to send thecorrect password—includingmodems that do not support themodem security handshake.

The automatically invokedpassword (and callback phonenumber, if used) is stored innonvolatile memory, so it will bemaintained if the unit loses poweror upon a quick (soft) reset.However, a factory reset will clearthe automatic password (andcallback number, if used) frommemory.

NOTEWhen APP is used, themodem will not fall back tospeeds lower than 7200 bps.

After a connection has beenestablished using the securityhandshake and automatic password(and callback phone number, ifused), a flashing “S” will bedisplayed in the top left corner ofthe EIA status screen to indicatethat a secure connection has beenmade. (If the modem is in a dialmode, “S”—and “D” for dial lineoccupied—will flash alternately.)

The APP process is summarizedbelow. Answer modem refers to thelocal modem; originating modemrefers to a remote modem; when itcalls or attempts to call the answermodem.

• An originating modem calls theanswer modem.

• The originating modemautomatically sends thepreprogrammed password viathe security handshake.

• If the answer modem isconfigured for APP withoutcallback, it confirms thepassword and connects.

For APP without callback, this isthe end of the process. For APPwith callback, the processcontinues:

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• Both modems go on-hook.

• The answer modem calls theoriginating modem back.

• Modems exchange securityhandshake (again) andconnect.

4.12 Configuring Modems for APPThe procedures for configuring theoriginating and answer modems forboth types of APP are summarizedbelow and then explained in detailin the subsequent sections.

4.12.1 APP WITHOUT CALLBACK

• Enter the same password in thefront panel password screen(on the LCD) of theoriginating modem and answermodem.

4.12.2 APP WITH CALLBACK

• Enter a password in the frontpanel password screen of theoriginating modem (the userpassword).

• A password must be entered inthe front-panel password screenof the answer modem (the mas-ter password). Any passwordwill do (even a single charac-ter), except that it should notbe the same as the user pass-word, and it should not be the

same as any other passwordstored in the answer modem’smemory (for APP or MPP).APP with callback will not func-tion if the master password isremoved.

• Use the Hayes AT &Z commandto store the user password andcallback phone number in theanswer modem’s memory.

4.12.3 PASSWORD SCREENS

For either type of APP, a passwordmust be preprogrammed throughthe PASSWORD screen of both theanswer and originating modems, asexplained below.

For APP without callback, use thesame password on both modems.For APP with callback, do not usethe same password—see Section4.12.2.

Establishing or Changing theAutomatic Password

The automatic password can bechanged (or initially established)using the front panel passwordscreens shown below. These screensare accessed via the PASSWORDscreen.

Change-Password Screen:

DEC SKIP INC

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MODEM 32144

4.12.4 VALID PASSWORD CHARACTERS

Valid password characters are Athrough Z (upper case or lowercase), 0 through 9 and thefollowing symbols: ! " # $ % & ' ( )* + , - . / Spaces function as validpassword characters; therefore, apassword that includes spaces willonly match another password withspaces in the same positions. Note,however, that a space in the firstcharacter position will disable thepassword. When the LCD cursor is in the same position as a space,the space is shown on the LCD as a flashing black box; otherwise,spaces appear as void spaces.

The following paragraph appliesonly to the user password enteredin the originating modem whenconfiguring modems for APP withcallback:

The only valid passwordcharacters are capital A through Z.If any characters outside this rangeare used, callback operation willnot function. No spaces betweenthe letters are allowed, except thatthe user password (as entered onthe front panel) must end with aspace.

Clear-Password ConfirmationScreen:

CONFIRM

NOTEThe change-password andclear password confir-

mation screens will not bedisplayed if the front panelis disabled.

To change or establish theautomatic password, selectCHANGE from the PASSWORDscreen. The change-passwordscreen will be displayed. If apassword has been previouslyprogrammed, it will be displayed.

Use the right and left arrowpushbuttons to move from onecharacter position to the next. The character at the current cursorlocation will flash on and off. Usepushbutton 1 to change thecharacter at the current cursorlocation to the next descendingcharacter or pushbutton 3 tochange it to the next ascendingcharacter. Use pushbutton 2 toskip through groups of characters(ascending). Use the arrowpushbuttons to move on to thenext character to be changed.

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Entering the Selected Password

When the new password is correctlydisplayed on the LCD, press theENT pushbutton. This will causethe new password to take effect.

The modems are configured for APP without callback whenmatching passwords are entered in the front panel password screensof both modems.4.12.5 APP WITH CALLBACK: STORINGTHE PASSWORD WITH CALLBACKNUMBER

If you have followed these instruc-tions to this point, the userpassword will be stored in the front-panel password screen of theoriginating modem, and a differentpassword (the master password)will be stored in the front-panelpassword screen of the originatingmodem, and a different password(the master password) will bestored in the front panel passwordscreen of the answer modem. (Themaster password should bedifferent from the user password,because it can be used to access theanswer modem directly, withoutcallback. The master passwordallows access for troubleshootingfrom a remote site.)

The final step in configuring themodems for APP with callback is to store the user password in theanswer modem’s memory, alongwith the callback phone number, as explained below.

From the DTE, use the Hayes AT&Z command and /S (a specialcommand) to store the userpassword (capital A through Z, nospaces) and callback number in aspecific memory location. Memorylocations 0 through 9 may be used.The following example shows howto store a user password andcallback number in memorylocation 3:

Enter AT &Z3=T5551212/SGRAPE

The callback number (phonenumber of the originating modem)in this example is 555-1212 (with Tused to specify tone dialing). Theuser password is GRAPE. (Whenthe user password is entered on thefront panel password screen of theoriginating modem, a space isrequired at the end. Do not use aspace at the end when storing thepassword with the AT &Zcommand.)

A remote user can now call fromthe specified callback number, 555-1212. The originating modem willsend the preprogrammed passwordGRAPE as part of the securityhandshake. The answer modemwill confirm the password andconnect by calling the originatingmodem back.

4.13 Disabling APP4.13.1 TEMPORARILY DISABLING APPTo temporarily disable either typeof APP, select CHANGE from the

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MODEM 32144

4.14 Manual-Response PasswordProtection (MPP)The modem can be configured for two types of MPP:

• MPP without callback—Themodem will pass a connectionon to the DTE interface onlyafter it receives a validpassword.

• MPP with callback—The answer modem will call backan authorized user after he or she enters a valid password.

Both types of security operationprovide security on incoming callsby requiring remote user tomanually enter a valid password.In addition, access to Hayes-compatible commands for viewingand storing phone numbers ispassword protected.

The MPP process is summarizedbelow.

• A remote (originating) modemcalls the local (answer) modem.

• Local modem answers.

• Remote user sends carriagereturn [CR].

• Answer modem confirmspassword and grants access (ifprogrammed for MPP withoutcallback) or initiates securitycallback (if programmed forMPP with callback).

PASSWORD screen. The change-password screen will be displayed.With the cursor in the firstcharacter position, presspushbutton 2 (SKIP) until a spaceappears (flashing ■ ). Then pressENT. The password will bedisabled.

With the password disabled, theanswer modem can connect toanother modem that is notequipped to use or is notconfigured to use APP (forexample, one where a password hasnot been entered in the front-panelchange-password screen). However,it will not be able to connect to amodem that is programmed with apassword for APP without callback.To restore the password, replacethe space with the first character of the password and press ENT.

4.13.2 CLEARING THE PASSWORD

To clear the front-panel passwordfrom memory, select CLEAR fromthe PASSWORD screen. The clear-password confirmation screen willbe displayed. Press pushbutton 2 toconfirm that you want to clear thepassword.

If no password is stored, themodem will be able to connect to other modems that are notequipped to use or are notconfigured to use an automaticpassword (APP). To temporarilydisable the automatic password, see the previous section.

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4.15 Commands for Enabling MPPModem configuration for MPP iscontrolled from the DTE by aspecial set of password commands.These commands are implementedby using the Hayes AT &Zcommand to store them inmemory. If an administrativepassword has been implemented,the front panel will be disabled andthe AT &Z command will notfunction until it (the AT &Zcommand) is unlocked. (Theprocedure for unlocking the AT&Z command is explained inSection 41.6, How to Use PasswordCommands.

The modem incorporates 10memory locations for storingtelephone numbers, passwords,and/or the MPP passwordcommands listed in Table 4-4. Toimplement a security command,use the Hayes AT &Z command tostore the command in a specificmemory location. The passwordcommands are listed in Table 4-4and explained in detail in thesections that follow.

Table 4-4. Password Commands for MPP.

Command Function Example Mem. loc.

/A Set/change administrative password; /ASECURITY 1

password-protects use of certain

Hayes commands.

/P Set password for— /PYELLOW 2-9

MPP without callback or

MPP with callback 4443535/PRED

/U User-defined text string. Used to /UHELLP 0

send a response to the remote

terminal user after a valid password

is received.

1Command string stored using AT &Z command.2Each command will function only in the listed memory locations.

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MODEM 32144

Rules for Using Passwords andPassword Commands (MPP)

• Memory locations 0 and 2-9 may be used for storing phonenumbers; locations 2-9 may be used to store passwords.

• The entire command string,including the AT &Zcommand, cannot exceed40 characters.

Passwords

• Passwords and commands may be entered in capitals orlowercase letters. (However,they will be stored andsubsequently displayed ascapitals.) Do not includenumber or spaces.

• For MPP without callback, /must be the first character in astorage location; for MPP withcallback operation, a phonenumber must be listed first in astorage location.

• Special characters (! @ ?, etc.)may be used for passwordsentered via the DTE interface,but these characters cannot beentered via the modem’s frontpanel.

• A phone number cannot bestored after /.

Commands

• Only one command (/A, /P, or /U) can be stored in eachmemory location.

• Do not leave a space after acommand.

• When using the /U command,do not include spaces orcontrol characters in thespecified text string.

4.16 How to Use PasswordCommandsTo Establish or Change theAdministrative Password:

For greatest security, anadministrative password should be used. If implemented, theadministrative password controlsaccess to the Hayes-compatible &Vand &Z commands. Thesecommands are required to view or modify the modem’s securityconfiguration (as explained in the following sections).

To establish or change anadministrative password:

Enter AT &Z1=/ASECURITY

but replace SECURITY with the password of your choice.

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NOTEThe administrative pass-word may only be stored inmemory location 1. Thecommand line, including AT&Z1=, cannot exceed 40characters.

To Unlock the &V and &ZCommands:

If an administrative password hasbeen implemented, the Hayes-compatible &V and &Z commandscannot be accessed unless they arefirst unlocked using the currentadministrative password. (&V isused to view the active modemconfiguration, stored phonenumbers, password commands and passwords; &Z is used to store phone numbers, passwordcommands, and passwords). Tounlock the &V and &Z commands,enter

AT &Z=/ASECURITY

or substitute other currentpassword in place of SECURITY.

The &V and &Z commands willnow be accessible.

To re-lock the &V and &Zcommands, enter AT Z. The DTEwill respond with OK, and the &Vor &Z commands will not functionuntil they are unlocked.

To Program MPP without CallbackOperation

Use the commands AT &Z and /Pto specify the password to be usedfor MPP without callbackoperation. The following exampleprograms memory location 5 forMPP without callback:

Enter AT &Z5=/PYELLOW

The password is YELLOW. Afterthe modems connect, the remoteuser presses the DTE Enter keyonce. The DTE will then promptthe user to enter the assignedpassword by displaying thePASSWORD? query. If the userenters the correct password,YELLOW, the call will beconnected.

NOTEMPP Passwords may only bestored in memory locations2 through 9.

To Program MPP with CallbackOperation:

Use the commands AT &Z and /Pto specify the callback phonenumber and password to be used.The following example programsmemory location 3 for callbackoperation:

Enter AT&Z3=T5551212/PCANARY

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MODEM 32144

To Program a Response to a CorrectPassword:

Enter AT &Z0=/UCONNECTED

but replace CONNECTED withthe message of your choice.

The DTE will respond with the specified message when the modem receives a correctpassword.

NOTEThe /U command andmessage can only be storedin memory location 0.

The callback number in thisexample is 555-1212 (with Tused to specify tone dialing); thepassword is CANARY. A remoteuser can now call from thespecified callback number, 555-1212. After the modems connect,the remote user presses the DTEEnter key once. The DTE will thenprompt the user to enter theassigned password by displaying thePASSWORD? query. Upon receiptof the correct password, CANARY,the local modem will call back theremote user at 555-1212. Once thisconnection is established, data maypass freely.

NOTEMPP passwords and callback numbers may only bestored in memory locations2 through 9.

39

CHAPTER 3: Options: Customizing the Modem Setup

Fig. 3-1. Summary of Pushbutton Control Functions.

If a menu has more than onescreen, each screen is numbered.The screen number is shown in theupper right corner of a screen (seethe sample screen below.) If amenu has no screen number, it hasonly one screen. Additional menuscreens (where present) showadditional option selections.

DISPLAYS PREVIOUSMENU SCREEN

DISPLAYS NEXTMENU SCREEN

EXITS FROMDISPLAYED

SCREEN

1 2 3 ENT

USED TO SELECT CHOICE 1, 2 OR 3 FROM THE LCD

(Each of the possible selections on the bottom lineof the LCD is identified as 1, 2 or 3 below the LCD.)

Arrow Pushbuttons

The left arrow (<--) and right arrow(-->) pushbuttons are used todisplay additional or previousscreens that are part of the samemenu. The right arrow pushbuttondisplays an additional menu screen(if there is one); the left arrowpushbutton displays the previousmenu screen. With respect to howthe LCD flow chart is set up, thearrow pushbuttons “move you”either right or left within the chart.

MAIN MENU <2>SETUP TEST RMT

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MODEM 32144

Numbered Pushbuttons

Pushbuttons 1, 2, and 3 correspondto segments 1, 2, and 3 of the LCDscreen. These segments (left,middle and right positions of theLCD screen) are numbered on themodem’s front panel. To make aselection from a menu screen,simply push the button with thesame number as the selection you want.

With respect to how the LCDflow chart is organized,pushbuttons 1, 2, and 3 will eithertake you to a lower level—or, wherethere is no route to a lower level,they will select an option.

ENT Pushbutton

To exit from a displayed screen,press the ENT (enter) pushbutton.With respect to how the LCD flowchart is set up, pushing the ENTbutton will move you upwardthrough the chart (toward theMAIN MENU). If you become lost, pressing the ENT buttonrepeatedly will return you to screen1 of the MAIN MENU. PressingENT repeatedly after you havearrived at MAIN MENU screen 1will cause the LCD to alternatebetween the EIA status screen andthe MAIN MENU. (In the case ofmost tests, the ENT button cannotbe used to exit the test screen oncethe test has been activated; youmust first press the ENT buttonand then select OFF to end the test.)

3.3 Selecting Options from the FrontPanel This section applies to all optionscreens on the front panel LCDexcept the Summary Setup screens,which are explained in Appendix B.

Options are accessed from theSETUP menu. As shown in theLCD flow chart, the SETUP menuconsists of six screens and isaccessed from screen 2 of theMAIN MENU. (With screen 2 of the MAIN MENU displayed,push button 1 to select SETUP.)

Once you have located the screenthat displays the option you want toaccess or change, select your choiceby pushing the button with thesame number as the selection youwant. Each selection on the bottomline of the LCD is numbered either1, 2, or 3 on the modem’s frontpanel (not on the LCD), as shownin Fig. 3-2.

41


Fig. 3-2. The Front Panel.

• The option choices you selectare automatically saved by themodem when you leave theSETUP menu.

3.3.1 DEC/INC(DECREASE/INCREASE) SCREENS

Several option screens show theabbreviations DEC and INC on the bottom line of the LCD display.This means that the numericalvalue shown on the top line (e.g.,a stored phone number) can be changed. Selecting DEC(pushbutton 1) will decrease thevalue; selecting INC (pushbutton3) will increase it.

SETUPQUICK LINE SPEED

< 1 >

1 2 3

LCD

Front panel

When an option is first selected,it will flash on and off on the LCD.However, it will not take effect untilyou leave the SETUP menu. Simplyaccessing an option screen will notchange the option, so do not beafraid to experiment with the LCDand pushbuttons.

Note the following importantpoints—

• Selected options do not becomeactive until you leave theSETUP menu.

• Changing some options willcause the modem toautomatically reset.

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MODEM 32144

3.3.2 EXAMPLE OF HOW TO SELECT ANOPTION

The example that follows illustrateshow options are selected. As youfollow the steps below, refer to theLCD flow chart (SETUP OPTIONSside). When you are done, you caneasily restore default settings forthe type of application you will beusing by selecting the appropriateQuick Setup (Table 3-1).

The example shows how tochange the volume of the modem’sspeaker from LOW or HIGH (thedefault setting) to MEDIUM. Tomakes this adjustment, you mustlocate the SPEAKER VOLUMEscreen on the LCD. To reach thisscreen, you must first access MAINMENU screen 2, then SETUPscreen 4 and then MODEMSETUPS screen 5, as explainedbelow:

After powering on the modem,press ENT to get the first screen ofthe MAIN MENU. Press the rightarrow pushbutton (—>) to go toscreen 2 of the MAIN MENU (sothe SETUP menu can be selected):

Press pushbutton 1 to access thefirst page of the SETUP menu:

MAIN MENU <2>SETUP TEST RMT

SETUP <1>QUICK LINE SPEED

Now press the right arrowpushbutton three times; this will cause SETUP screen 4 tobe displayed:

SETUP <4>TEST EIA MODEM

Press pushbutton 3 to selectMODEM (for MODEM SETUPS).The first MODEM SETUPS screenwill be displayed:

MODEM SETUPS <1>CDLVL TXLVL

Press the right arrow pushbuttonfour times to reach MODEMSETUPS screen 5:

MODEM SETUPS <5>FP SPK SPKVOL

43


Press pushbutton 3 to selectSPKVOL (speaker volume). TheSPEAKER VOLUME screen will be displayed:

3.3.4 AUTOMATIC CONFIGURATIONSAVE FEATURE

When you exit the SETUP menu,the modem automatically saves itscurrent configuration (i.e., optionsetups, including any changes youhave selected) to its internalmemory. The saved configurationwill remain in effect until it ischanged—even if the modem losespower.

3.3.5 HOW TO RETURN TO DEFAULTSETTINGS

The factory default settings aredifferent for each of the QuickSetup configurations available tothe modem [2-wire dial Hayes, 2-wire dial V.25 bis, etc.]. To returnto the factory-default settings forany of these configurations (except2-wire dial Hayes), go to theQUICK SETUP menu and selectthe desired configuration.

The 2-wire dial Hayes QuickSetup does not recall the factory-default setting, it recalls the storeduser profile 0 or 1, depending onwhich has been designated as thedefault; see &Y command.

To entirely reconfigure themodem to the state it was in whenshipped from the factory, hold inthe right arrow pushbutton as youpower up the modem until thewords “FACTORY DEFAULT”appear on the LCD.

SPEAKER VOLUMELOW MEDIUM HIGH

The currently selected setting will be flashing on and off. Presspushbutton 2 to switch the volumesetting to MEDIUM. “MEDIUM”will begin to flash on and off,indicating that this setting has been selected (although the newselection will not become activeuntil you exit the SETUP menu).To return to the first screen of the MAIN MENU, press the ENTbutton several times.

3.3.3 HOW TO RETURN TO THE EIASTATUS SCREEN

Once your selection is complete,you will most likely want to returnto the EIA status screen. Do this by pressing the ENT pushbuttonseveral times—exactly how manytimes will depend on which screenyou are exiting from. (If the modemis in a test mode, you must in mostcases press ENT and then selectOFF, which will end the test, beforethe ENT button can be used to exitthe test screen.)

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MODEM 32144

3.4 OptionsThe rest of this chapter describesthe options available from themodem front panel. The optionsare presented in the same order inwhich they appear in the LCD flowchart (which is shipped with themodem). For each option, allpossible choices (availableselections) are explained.

The line below each optionheading indicates the applicabilityof the option: A mode (like QuickSetup mode) is listed only if theoption is effective in that mode andif it can be of practical use in thatmode.

For a concise summary of themodem options and optionchoices, see the LCD flow chart.The default settings for eachoption are listed in Appendixes Aand B.

Quick Setups

All modes

The Quick Setups (one for eachoperating mode) are unique inthat they affect the entire modemconfiguration. See Chapter 2 andAppendix A.

Line Type

All modes

2W-D. This selection (2-wire dialline) is used for dialupapplications.

2W-LL. This selection (2-wireleased line) is used for leased lineapplications that use 2-wire lines.

4W-LL. This selection (4-wireleased line) is for leased lineapplications that use 4-wire lines.

3.5 Speed (Data Rate) OptionsSpeed Limit

All modes

The Speed Limit option allowsyou to set a minimum and/ormaximum data rate. The modemwill automatically operate at thehighest possible data rate withinthe limits selected, as indicated inTable 3-1. (In Hayes mode, themaximum rate of the originatemodem is determined by theoriginate modem’s DTE autobaudrate. See Table 3-1.)

EIA-23. This choice is available forsetting the maximum rate only. IfEIA-23 is selected, the rate will beset at either 9600 or 4800 bps,depending on the condition of pin23 on the EIA interface: Pin 23high (greater than or equal to +3volts) = 9600 bps; pin 23 low (lessthan or equal to –3 volts) = 4800bps.

45


Table 3-1. Effect of Speed Limit Settings on Data Rate.

Max rate Dialer Resultant data rate, bpssetting, bps option

Leased line modes

14,4001 xx 14,4001

19,200 xx 19,200

12,0001 xx 12,0001

9600 xx 9600

72002 xx 72002

4800 xx 4800

300 to 2400 xx 2400

EIA-CTRL xx 9600 or 48003

Dial modes—Answering

300 to 19,200 xx Negotiated between min.

and max. setting

EIA-CTRL xx 9600 or 48003

Dial modes—Originating

300 to 19,200 OFF or DTR Negotiated between min.

and max. setting

EIA-CTRL OFF or DTR 9600 or 48003

xx HAYES4 Negotiated between autobaud

speed and minimum setting

on originate modem4

xx Does not matter—setting does not affect data rate.1Both 14,000 and 12,000 bps rates are available for the modem.27200 bps is available only if V.32bis mode is enabled (via Summary Setup,

V.32 Mode option).39600 bps if EIA pin 23 is high, 4800 bps if pin 23 is low.4If SYNC AFTER DIAL is enabled (using the &Q1 command), the rate will be

negotiated between the autobaud speed and 1200 bps.

46

MODEM 32144

Speed Matching

If speed conversion is not desired,the DTE interface rate should beset to follow the rate at which themodem connected (i.e., DTE rate =DCE rate, or speed matching).Change the Speed matchingparameter shown in the diagramto 1 (enable).

NOTESpeed matching is onlyeffective for dial applicationsand will only function if errorcorrection or buffer mode isenabled.

Speed Type

All modes

The V.32 master handshakenormally used by the modem isincompatible with the CCITT V.33and Bell 208 handshakes. However,the modem (only) can beconfigured for either V.33 or Bell208 compatibility, and for Bell 208operation. (To determine if amodem supports Bell 208operation, see Section 2.7.)

V.33 or Bell 208 speed types can be set independently of otheroptions via the SPEED TYPEscreen; however, to ensure properoperation, it is recommended that you use the V.33, Bell 208, or V.32/208 Quick Setupconfiguration, as explained inChapter 2.

The available speed-typeselections are listed below. Usepushbuttons 1 (DEC) and 3 (INC)to cycle through the speed-typeselections. The currently selectedspeed type is displayed in theSPEED TYPE screen (upper rightcorner), as shown in Fig. 3-3.

47


Fig. 3-3. Current Speed Type Selection.

Both connected modems must be set for 208A/B operation. For 2-wire applications, the carrieroption must be set for switchedcarrier operation (SWITCH) viathe CARRIER screen, and CTSmust be set to follow RTS (CTSto EIA option).

V.29. This selection is availableonly on models that include theV.29/V.27/V.26 option. Itconfigures the modem for V.29operation (for data rates of 9600,7200, or 4800 bps). To select aspecific data rate, use the SpeedLimit option to select 9600, 7200,or 4800 bps (only) as the minimumand/or maximum data rate (DCERATE). In V.29 mode, the modemdoes not support automatic rateadjustment (fallback) or errorcorrection.

V.32. The modem normally usesthe V.32 handshake. (The modemalso uses this handshake forV.32/14.4 Kbps operation.)

V.33 operation is available on the modem for 4-wire leased-linesynchronous operation only. Theavailable data rates are 14.4 and12.0 Kbps. Either of these rates may be set as the maximum orminimum by using the Speed LimitMAXIMUM RATE and MINIMUMRATE screens.

Both connected modems must beset for V.33 leased line operation.

208. This selection (available onlyon models that support Bell 208operation) provides Bell 208Acompatibility for 2-wire or 4-wireleased line operation and Bell 208Bcompatibility for 2-wire dialoperation. Operation is full duplexin 4-wire leased line mode only. InBell 208B mode, synchronous V.25bis autodialing is available, butHayes operation is not. Calls maybe originated from the front panel.The data rate is fixed at 4800 bpsfor 208A/B operation, and the dataformat is synchronous only.

SPEED TYPE V.32DEC INC

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MODEM 32144

AUTO. This selection configuresthe modem for V.32/208 auto-detectmode. This mode allows the modemto automatically select V.32 or Bell208 operation, depending on themode of the originating modem.

Note—• To enable V.32/208 auto-detect

mode, the Speed Type optionmust be set to AUTO and theV.32/208 auto-detect SummarySetup option must be set to 1for enable. This option isshown in Appendix B, Fig. B-6.

• Selecting the V.32/208 QuickSetup automatically sets thespeed type to AUTO—andenables the Summary Setupauto-detect option (sets it to 1).

• When the speed type is set toAUTO, the ALX will nothandshake in V.22 bis, Bell212/103 or V.21/V.22,V.23mode.

• All information in the 208section above applies toV.32/208 auto-detect mode.

Three options intended only for208A/B and V.33 operation areaccessible through MODEMSETUPS screen 7. These optionsallow you to select constant orswitched carrier, set CTS to followRTS or set CTS to be always on,or specify an RTS-CTS delay time.For further information, see theCarrier, CTS, and RTS-CTS Delayheadings later in this chapter.

For further information on Bell208 mode, see chapter (sectiontitled Dumb Mode and Bell 208Operation).

3.6 V.42 Error Correction OptionsThe modem supports both CCITT V.42 error correction andMicrocom Networking Protocol(MNP) error correction (classes 1through 5). V.42 and MNP bothprovide end-to-end errorcorrection through an automaticrepeat-transmission requestalgorithm. Both types of errorcorrection enable the modem todetect data-transmission errors and automatically requestretransmission of adversely affecteddata until it is received correctly.

Either error-correction standard(V.42 or MNP) may be enabled foreither dial or leased-line operation.However, error correction canfunction only if all of the followingconditions are present:

• The modem that the modem is communicating with must beequipped with the same type oferror correction (V.42/V.42 bisor MNP).

• The same type of errorcorrection (V.42/V.42 bis orMNP) must be enabled at bothends of the communicationlink.

• Both communicating modemsmust be configured forasynchronous data format.

49


• The connected systems mustsupport data flow control (have buffering capabilities).

Note—• The V.42 and MNP error-

correction options (listed anddescribed below) are effectiveonly when all of the conditionslisted above are present.

• Error-correction options cannotbe changed when the modem ison-line.

• For valid test results, disableerror correction beforerunning diagnostic tests.

User-selectable options let youconfigure the modem for V.42(LAPM) error correction only,MNP error correction only, or V.42error correction with MNP as thefallback (alternate) errorcorrection protocol. Datacompression may also be enabledby selecting either V.42 bis or MNPclass 5 error correction. Othererror-correction options are alsoavailable.

The available error-correctionoptions are V.42 Mode, MNP Class(class limit), Break Handling, V.42Selection, Buffer Mode/SpeedConversion, DTE Speed, DTE-DCEand DCE-DTE Flow Controloptions, and Pass-through FlowControl. All of these options affectthe type of error correctionselected via the V42 SELECTIONscreen (discussed below), exceptthat the MNP Class option is

applicable only to MNP operation.The error correction options can

be selected in any order, but thefollowing sequence is suggested:First select the type of errorcorrection desired from the V.42SELECTION screen. Next make aselection from the V.42 MODEscreen. Then select other errorcorrection options as appropriatefor your application.

Two additional error-correctionoptions are described near the endof this chapter, in Section 3.16,Options Accessible Only viaSummary Setup. These additionaloptions are SelectiveRetransmission and DCE Pass-through Flow Control.

V.42 Mode

Hayes, V.25 bis, Dumb, Leased-linemodes (except V.33)

The V.42 Mode settings describedbelow apply to the type of errorcorrection selected via the V42SELECTION screen. For example,if LAPM ONLY has been selectedas the error correction protocol,and MANDATORY is selected fromthe V42 MODE screen, V.42 or V.42bis error correction will beactivated—or if it cannot be, themodem will hang up.

50

MODEM 32144

OFF. Error correction will bedisabled.

MANDATORY. Error correctionwill be activated. If the modemcannot establish a connection using the type of error correctionselected via the V.42 Selectionoption, it will hang up.

TIGHT FIT = AUTO. The modemwill fall back to buffer or non-buffermode if conditions do not allow itto establish a connection using thetype of error correction selected viathe V42 SELECTION screen.

MNP Class (Limit)

Hayes, V.25bis, Dumb, Leased Linemodes (except V.33)

This option is effective only whenMNP error correction is active. Itlimits MNP operation to theselected MNP class or lower. (MNP classes 1-5 are available.) In general, the higher MNP classesprovide greater throughput. Class5, the default, can provide as muchas 2-to-1 data compression over thetransmission link.

V.42 Selection Options

The following two options areavailable through the V.42SELECTION screen:

Protocol

Hayes, V.25 bis, Dumb, Leased line modes (except V.33)

LAPM/MNP. The modem willattempt to establish a connectionusing the V.42 link access protocolfor modems (LAPM). This is theprimary error correction protocolunder the CCITT V.42 standard.If such a connection cannot beestablished (because the othermodem does not support LAPM oris not configured for LAPM), themodem attempts to establish aconnection using MNP class 5as the fallback (alternate) error-correction protocol.

NOTEWhen operating in LAPMmode, the modem uses V.42error correction unless V.42bis is enabled via the V.42bis option. (V.42 and V.42biserror correction both useLAPM.)

LAPM ONLY. The modem willonly attempt to establish an LAPMconnection (will use only V.42 orV.42 bis error correction).

MNP ONLY. The modem willonly attempt to establish an MNPconnection.

51


NOTEIf a connection cannot beestablished using theselected protocol LAPM/MNP,LAPM ONLY or MNP ONLY),the action the modem willtake depends on the V.42mode setting. See V.42MODE.

V.42 bis Operation

Hayes, V.25 bis, Dumb, Leased linemodes (except V.33)

V.42 bis operation provides errorcorrection with data compression.Like V.42 error correction, V.42 bisuses the link access protocol formodems (LAPM). V.42 bisoperation may be enabled ordisabled.

Break Handling

Hayes, V.25 bis (Async only),Dumb, Leased line modes (exceptV.33)

When error correction is active, a break signal is relayed with an“attention” packet. The breakhandling option determines howthe attention packet is sent.

NONE. No attention packet is sent.

DESTRUCTIVE/EXPEDITED(DESTR/EXP). All data in thebuffer is deleted; the attentionpacket is then passed through thechannel.

NON-DESTRUCTIVE/EXPEDITED (NDT/EXP). Theattention packet is passed throughimmediately, but data in the bufferis not deleted.

NON-DESTRUCTIVE/NON-EXPEDITED (NDT/NEXP). Theattention packet is passed throughthe channel in sequence, and anydata is buffered; this preserves thesequence of data and breaksreceived.

Buffer Mode/Speed Conversion


This option enables or disablesspeed conversion (forasynchronous operation only)between the DTE and modemwhen error correction is not used.

ENABLE. When error correctionis not active, the V.42 circuit willfunction as a buffer between theDTE and the modem and willprovide transmission-speedconversion.

DISABLE. Speed conversion isnot allowed.

DTE Speed


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MODEM 32144

Flow Control

The flow control options controlthe data flow according to theavailability of memory in thebuffer. Flow control can be setindependently for the terminal to the modem (DTE-DCE) and forthe modem to the terminal (DCE-DTE). The flow control optionsinclude DTE-DCE, DCE-DTE andPass-through Flow Control.

Note the following:

• Flow control only applies toasynchronous connections withV.42 error correction or buffermode enabled.

• When flow control is disabled,the DTE data rate must beequal to or less than themodem data rate, and the localand remote DTE data ratesmust be equal. (This precludesthe need for flow control—which some DTE devicescannot handle—and avoidsbuffer overflow.)

• For DTE-DCE and DCE-DTEFlow Control options: WhenRTS on/off or CTS on/off flowcontrol is used and a bufferconnection has beenestablished, conditions that will stop the data flow (e.g.,dropped RTS) should not bepermitted for long periods, if possible, to reduce thepossibility of buffer overflow.

This option controls the DTEspeed; however, it is effective onlywhen the modem is operating inV.42 mode, MNP mode or buffermode. (If the modem is not in oneof these modes, the DTE speed willbe the same as the connect rate.)

The DTE speed can be set for38.4, 19.2, or 115.2 Kbps or 9600,4800, 2400, 1800, 1200, 600, 300, or 110 bps (except that 1800 bpsis not available if the modem isin Hayes mode). The default DTE speed is 38.4 Kbps.

DTE speed refers to the speed ofdata transfer between the DTE andthe local modem—it is notnecessarily the same as the datatransmission speed between theconnected modems. If flow controlis disabled, the DTE speed must beequal to or less than the modemspeed, and the local and remoteDTE speeds must be equal.

For Hayes mode operation, thisoption sets the default DTE speedthat will be effective after powerupor after a full modem reset.However, the default DTE speed isautomatically overridden when themodem is autobauded (when an“AT” attention code is sent to themodem).

53


Fig. 3-4 illustrates the available flow-control options.

RTS on/off. The Request to Sendsignal controls data flow from themodem to the DTE. (RTS on/off isalso called hardware, physical orout-band flow control.) Thisselection enables flow control forthe local modem only.

DTE DTE

DTEpass-throughflow control

Tx linkflow control

DCEpass-throughflow control

Rx linkflow control


Tx linkflow control


Rx linkflow control

Rx linkflow control


Tx linkflow control


TD

RD

RD

TD

Modem Modem

Fig. 3-4. Flow-Control Options.

DTE-DCE Flow Control


NONE. This setting disables flowcontrol. All flow-control charactersare passed through thecommunication channel.

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MODEM 32144

DTE Pass-through Flow Control


Pass-through Flow Control affectsDTE-DCE flow control only. Thisoption determines whether flow-control characters received fromthe local DTE will be passed to theremote modem (if controlcharacters are used for flowcontrol).

ENABLE. Flow control charactersare passed to the remote end of thecommunication connection afterthe modem acts upon them.

DISABLE. Flow controlcharacters are not passed.

3.7 Address

All modes

The address screen allows you toset the address of the modem atyour location. An address may beuseful if the modem will be used in a rack enclosure or in a networkenvironment.

The available address numbersare 000,000 through 999,999. Onthe ADDRESS screen, the threedigits to the right of the comma arethe unit address number. The threedigits to the left are the groupaddress number. To change theaddress, use the right and leftarrow pushbuttons to go to the

DC1/DC2. This option insertsthe control characters ^R and ^Qinto the data stream to stop andstart/restart the flow of data froma device. (DC1/DC2 is also calledsoftware, logical, or in-band flowcontrol.)

DC1/DC3 (X-ON/X-OFF). Thisis the most common method offlow control. It inserts the controlcharacters ^S and ^Q into the datastream to stop (^S) and start/restart (^Q) the flow of data.(DC1/DC3 is also called software,logical, or in-band flow control.)

NOTEWhen using the modem forbinary file transfer, in-bandflow control (flow controlusing control characters)must be disabled. In thiscase, use hardware flowcontrol or, as an alternative,lower the DTE speed toreduce the possibility ofoverflow.

DCE-DTE Flow Control


All information given aboveunder DTE-DCE Flow Control alsoapplies to the DCE-DTE (modemto terminal) flow control option,except that the CTS, Clear to Sendsignal, is used to control DTE-DCEdata flow.

55


NOTEDTR dialing for V.25 bismode or Penril autodialermode cannot be enabledthrough the DIALER screen.To select DTR dialing forV.25bis or Penril mode, youmust use the Penril/V.25bisDTR Dialing option.

V.25 bis Dialer Modes

V.25 bis mode

Any of the selections from theDIAL V25 bis screen will enable the V.25 bis autodialer.

The three selections on the DIALV25bis screen allow you to select adata protocol that is appropriatefor the DTE the modem isconnected to. The choices are—ASYNCHRONOUS (Asyn)SYNCHRONOUS, CHARACTERORIENTED (Syn_c), andSYNCHRONOUS, BIT ORIENTED(Syn_b)

3.9 Auto-Answer OptionAuto-Answer

Hayes, V.25 bis, Dumb, 208,V.32/208 modes

This option determines whetheror not a call is automaticallyanswered when the phone rings.

digit you want to change. Then usepushbutton 1 to decrease (DEC) a number and pushbutton 3 toincrease (INC) it. The defaultaddress is 999,999.

3.8 Dialer ModeSeveral dialer mode options can be selected from the DIALER and DIAL V25bis screens.

Dialer

All modes

See also V.25 bis Dialer Modesbelow.

OFF. The autodialer is off,meaning the modem will operatein Dumb mode only. Calls must bemade using the front panel AUTO-DIAL function or they must bemanually originated.

HAYES. The autodialer willautomatically dial previously storedphone numbers, and the modemwill respond to Hayes commands.

DTR. This selection enables DTRdialing, an option that allows youto set up the modem toautomatically dial a stored numbereven when the autodialer has notbeen enabled.

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MODEM 32144

Setting the Auto-Answer optionto ENABLE resets Hayes moderegister S0 to 1 (meaning that callswill be answered on the first ring).

3.10 Data Format OptionsData Format (Sync or Async)

V.25 bis, Dumb, Leased line modesThe data-format setting for thelocal modem and for the remotemodem must be the same.

ASYNCHRONOUS. Data istransmitted and received in thecharacter asynchronous format.The character length (next option)must be the same for bothcommunicating modems.

SYNCHRONOUS. If this settingis selected, data must betransmitted and received in thesynchronous format. Theappropriate transmitter clockingsetting must be selected—seeTRANSMITTER CLOCKING laterin this chapter. The synchronousdata format is not available for datarates of 300, 19.2, or 38.4 Kbps.

Character Length

All modes (asynchronousoperation only)

This option selects a characterlength of 9, 10, or 11 bits forcharacter asynchronous operation.The same character length must be

selected for both the local and theremote modems. Use pushbuttons1 and 3 to select the desiredcharacter length. The most widelyused character-length setting is 10 bits.

9 BITS: 1 start bit, 7 data bits,and 1 or more stop bits.

10 BITS: 1 start bit, 8 data bits,including parity, and 1 or morestop bits.

11 BITS: 1 start bit, 9 data bits,including parity, and 1 or morestop bits.

Parity

All modes

Parity selections will be effectiveonly if error correction or buffermode has been enabled or if themodem is in 2-wire dial Hayesmode. For most applications, parityshould be set to NONE.

The following parity options areavailable: NONE (no parity),ODD, EVEN, MARK (parity isalways 1) and SPACE (parity isalways 0). All parity settings exceptNONE automatically enable parityconversion (except in Hayesmode), meaning that the parity ofreceived data will be converted tomatch the selected parity option.

57


NOTEFor Hayes mode operation,the RX Space Disconnectand TX Space Disconnectoptions must both beenabled or must both bedisabled.

TX (Transmit) Space Disconnect

Hayes, V.25 bis, Dumb modes

When TX Space Disconnect isenabled, the modem will transmit 4 seconds of space prior todisconnecting from the line. Thisensures a clean disconnect if RXspace disconnect is enabled on theremote modem.

NOTEFor Hayes mode operation,the TX Space Disconnectand RX Space Disconnectoptions must both beenabled or must both bedisabled.

Carrier Disconnect

V.25 bis, Dumb modes

If enabled, a 400-ms loss ofcarrier signal will cause the line to be disconnected.

(To set this option for Hayesmode, use S register S10.)

In Hayes mode, autobaudoverrides the front panel paritysetting; this occurs when themodem receives the AT attentioncode.

3.11 Disconnect OptionsWhen the modem is operating inV.25 bis or Dumb mode, it isnecessary to disconnect the modemfrom the telephone circuit oncecommunications is completed. Themost common form ofdisconnection is by dropping theData Terminal Ready (DTR) signalfrom the DTE. However, someapplications may require one of thefive available automatic disconnectmethods listed below.

For all five disconnect options,“disabled” means the modem willnot disconnect in the presence ofthe conditions specified below

RX (Receive) Space Disconnect


If this option is enabled, a 1.6-second continuous space will causethe modem to disconnect.

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MODEM 32144

Line Current Disconnect


If enabled, a 400-ms loss ofcurrent will cause the line to bedisconnected.

(To set this option for Hayesmode, use S register S10.)

RTS Disconnect


When RTS Disconnect isenabled, if RTS is off for a selectedperiod of time (20 to 140 seconds,user-selectable), the line will bedisconnected. Use pushbuttons 1and 3 to set the RTS-OFF periodrequired for a disconnect.

3.12 Test OptionsThe test options affect certain tests(as explained below) but do notactivate tests.

DSR During Analog Loopback

All modes

When ON is selected, the DataSet Ready signal is forced on whenthe modem is in the analogloopback test mode. In general,this option should be left ON (thedefault selection).

Remote Test

All modes

The Remote Test option allowsyou to prevent remote digitalloopback or remote digitalloopback self tests from beinginitiated on the local modem froma remote modem. If DISABLE isselected from the REMOTE TESTscreen, the local will ignore test-initiation signals from a remotemodem. If ENABLE is selected,tests can be initiated from a remotemodem.

Note that there are two REMOTETEST screens. One is for theoption just described; the other isused for selecting remote digitalloopback tests. The Remote Testoption screen (for preventing orallowing remote testing) looks likethis:

REMOTE TEST ENABLE DISABLE

3.13 EIA OptionsThe seven options described nextallow control over specific EIAinterface signals.

59


CTS to EIA


Regardless of the setting selectedfor this option, Clear to Send(CTS) goes low. When DCD goeshigh during a V.42 error correctionhandshake or when DCE-DTE flowcontrol is set to CTS on/off and aconnection has been establishedwith error correction or buffermode enabled.

NORMAL. The Clear to Sendsignal is on while the modem is on-line.

RTS. The CTS signal immediatelyfollows the RTS signal with nodelay.

TRUE. The CTS signal followsDTR.

CTS can also be set to be ON atall times regardless of DTR by usingthe Summary Setup feature.(However, if CTS on/off has beenselected from DCE-DTE screen 1,V.42 flow control, while active, willoverride the CTS ON selection.)

To set CTS ON, refer toAppendix B, Fig. B-4 , EIAINTERFACE OPTIONS diagram.Note that if you set CTS to ONusing Summary Setup and thenmake a selection from the CTS toEIA screen, the selection from theCTS to EIA screen will cancel theSummary Setup (CTS ON)selection.

NOTEThe modem also supports aCTS option intended onlyfor V.33 and Bell 208A/Boperation, which isdescribed later in thischapter under V.33 and Bell208A/B Options.

CD to EIA

All modes

NORMAL. Carrier Detect (CD) is on while the modem is on-line.

TRUE. CD follows DTR suppliedfrom the DTE.

TOGGLE. CD turns on wheneverDTR is present and then toggles offfor 500 ms upon DTR disconnect,allowing the attached DTE torecognize that the call has endedand the connection has beendropped.

DSR to EIA

All modes

NORMAL. Data Set Ready (DSR)is on while the modem is on-line.

TRUE. DSR follows DTRsupplied from the DTE.

CROSSOVER (XOVER). DSR isON without DTR and toggles for500 ms upon local or remotedisconnect.

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MODEM 32144

DTR from EIA

All modes

This option allows the user toforce the Data Terminal Ready(DTR) signal on (TRUE), whichmay be needed if your computer orcommunication software does notsupply a DTR signal.

NORMAL. DTR is supplied bythe DTE. When DTR goes low, themodem sends a space disconnect(if TX Space Disconnect isenabled) and goes on-hook.

TRUE. The DTR signal isinternally forced ON regardless of the DTR status at the interface.

DTE Control of ALB (ALB- DTECtrl’ed)

All modes

Analog loopback (ALB) testingcan be initiated from the DTE viapin 18. Positive voltage activates the test, whereas negative voltageresults in normal operation.Disabling this option keeps themodem from responding to pin 18.

DTE Control of RDL (RDL- DTECtrl’ed)

All modes

Remote digital loopback (RDL)testing can be initiated from theDTE via pin 21. Positive voltageactivates the test, whereas negative

voltage results in normal operation.Disabling this option keeps themodem from responding to pin 21.

Test Mode (TM to EIA)

All modes

This option controls pin 25, thetest mode (TM) indicator, on theRS-232 interface connector.NORMAL. TM output is high(active) only during test modes.TRUE. TM output is high all ofthe time.

3.14 Modem SetupsThe options listed below, throughRTS-CTS Delay, are available viathe MODEM SETUPS screens.

Carrier Detect

All modes

This option selects the carrierdetect level. To make a selection,first select either LEASED or DIALfrom the CARRIER DET. LVLscreen, depending on yourapplication. The appropriatecarrier detect level screen will then be displayed.

Leased-Line Applications

For leased-line use, the carrierdetect level can be set for –43, –33or –26 dBm. The default setting is–26 dBm.

61


Dialup Applications

For dial line use, the carrier detectlevel can be set for –51, –41 or –34dBm. The default setting is –51dBm.

Transmit Level

All modes

This option controls the modem’stransmission level. To make aselection, first select eitherLEASED or DIAL from theTRANSMIT LEVEL screen.

Leased Line Applications

For leased lines, the transmissionlevel can be set between 0 and –15dBm, in 1-dBm steps. The standardsetting is 0 dBm. (Use pushbuttons1 and 3 to select the desiredtransmission level.)

Dialup Applications

The transmission level for dial linescan be set as either programmable,if you are using RJ-45S connectors,or permissive, fixed at –10 dBm+/–1 dBm, which is the mostcommon setting.

Signal Quality

All modes

This option sets the threshold forthe ER (error) indication duringnormal operation. You can chooseeither 10^3, one error in 1000 bits,or 10^5, one error in 100,000 bits.The settings of the Signal Qualityand Carrier Detect Level optionsdetermine the threshold values themodem uses as criteria for enteringLeased Line Auto-Recovery mode.

Compromise Equalizers


NOTEThe compromise equalizersonly affect V.32 operation(4800 bps to 14.4 Kbps,asynchronous/synchronous,full duplex).

For most applications, theautomatic adaptive equalizersetting will provide all the equaliza-tion necessary to compensate forline impairments, meaning thatequalizer adjustments generally willnot be necessary. However, in theevent that equalizer adjustment isneeded, any of four types ofcompromise equalization can beselected: Type I (T-I on the LCD),Type II (T-II), Type III (T-III) andType IV (T-IV). The equalizer canalso be turned OFF.

62

MODEM 32144

Where line conditions areatypical, it may be necessary toadjust the equalizers to optimizethe signal quality. If adjustment isnecessary, refer to the qualityscreen for guidance; this screenshows a relative indication of thesignal quality, in both numericand graphic form.

Trellis Code


Trellis coding providesperformance advantages for allmodulation patterns. The modem’sCCITT compliant trellis coder isnormally enabled at speeds of 7200 bps and above, but may benegotiated off by a modem that isnot equipped with a trellis coder at9600 bps. The trellis code optionallows the user to enable or disablethe trellis coder.

Transmitter Clocking

All modes

This option selects one of threepossible sources for the transmittertiming signal:

INTERNAL. The timing of themodem and data terminaltransmitting circuits is provided by an internal clock within themodem.

RECEIVED (RX-CLK). Thetiming of the data received fromthe remote modem is used tocontrol the timing of the trans-mitted data. This timing mode isused if the modem’s transmittiming must be controlled by aremote source.

EXTERNAL. The timing of the modem and data-terminaltransmitting circuits is synchro-nized to an external clock fromwithin the data terminal and isprovided to the modem via theDTE connector pin 24. This mode of clocking is used if theDTE must be in control of themodem’s transmit timing. Themodem’s minimum and maximumspeed must be set to approximatelythe same speed as the DTE clock.(To set the maximum speed, usethe Speed Limit option.)

T1 Timer


The T1 Timer option is onlyeffective if the Summary SetupMultimode Handshake option is set to 0 (T1 timer).

The T1 Timer option determineshow long the ALX modem willattempt to handshake with a callingV.32 modem before falling back toa lower speed. The available T1Timer settings are 0, 0.3, 0.8, 1.6and 3.0 seconds.

63


Normally, as part of the V.32handshake, the calling modembegins sending a sequence to theanswer modem while the answermodem is still sending answertone—in this case, there is no T1timer. However, the V.32Recommendation allows for a T1time of up to 3 seconds, meaningthat the answer modem may be setto wait (before falling back) for upto 3 seconds.

Auto-Retrain


If the modem makes aconnection at one of the V.32 rates(4800 bps to 14.4 Kbps) or V.22 bisrate (2400 bps), it can request thatthe remote modem send a retrainsequence.

ENABLE. The modem willrequest a retrain sequence.

DISABLE. The modem will notrequest a retrain sequence.

Answer/Originate Default

Leased line modes (and manualoriginate/answer dial operation)

This option sets the modem todefault to either answer ororiginate status when it makes aconnection at one of the V.32 rates(4800 to 14.4 Kbps). It also appliesto the V.22 bis rate (2400 bps), fordial operation only.

ANSWER. The modem is set toanswer mode.

ORIGINATE. The modem is setto originate mode.

Answer Tone


The answer tone frequency isselectable only if the maximumdata rate has been set to 1200 bps(via the SPEED LIMIT menu), inwhich case the answer tone can beset to either 2225 or 2100 Hz.Otherwise, the answer tonefrequency will be 2100 Hz (thestandard for V.32 operation). Ingeneral, this setting should not be changed (even for fallback withBell standard modems, which use a2225 Hz answer tone).

Front-Panel Control

All modes

For security purposes, this optionmay be used to make it difficult forunauthorized users to modify themodem’s configuration. If Front-Panel Control is disabled, themodem will not respond to QuickSetup selections or to changesmade through option screensaccessed via the SETUP menus. In addition, Hayes configurationcommands (and the &W and &ZHayes commands) will have noeffect, and stored user profiles (forHayes mode) cannot be altered.Note that even if Front-Panel

64

MODEM 32144

Control is disabled, front-panelscreens that do not affect themodem configuration (such asAUTO-DIAL and test modes) will function.

Speaker

Two speaker options are available:Speaker Control and SpeakerVolume.

Speaker Control

All modes

ON. Speaker is on during the fullmodem handshake process andwhile the unit remains on-line.

OFF. The speaker is off; the callcannot be audibly monitored.

ON TILL CD. Speaker remains on until a carrier signal (CD) isdetected.

Speaker Volume

All modes

The speaker volume can be set to LOW, MEDIUM, or HIGH.

Guard Tones

Hayes, V.25 bis, Dumb modesGuard tones are used—in V.22 and V.22 bis modes only—to assureproper band separation on systemsthat use international telephonecircuits. Unless you will be usinginternational circuits in one of

these modes, you should turn theguard-tone option OFF. If guardtones are required, their frequencycan be set to 550 Hz or 1800 Hz(the most commonly used guard-tone frequency).

V.13 Operation

V.25 bis, Dumb, Leased-line modes(synchronous operation only)

OFF. V.13 operation is off. Thissetting allows normal full-duplexoperation. (All other selections arefor enabling V.13 operation.)

TX ONLY. Status of RTS will besent to remote modem.

RX ONLY. Carrier Detect (CD)will be controlled by V.13 signalsfrom the remote modem.

TX AND RX. Status of RTS willbe sent to remote modem, and CDwill be controlled by V.13 signalsfrom the remote modem.To select one of the four V.13options, press pushbutton 1 or 3—with the V13 screen displayed—until the selection you want isdisplayed. For half-duplex point-to-point applications, select TX ANDRX. For multidrop-typeapplications, select RX ONLY forall modems at the host site and TXONLY for all modems at theremote site.

65


NOTEIf V.13 operation is enabled(TX ONLY, RX ONLY or TXAND RX), the data format isautomatically changed tosynchronous. However, ifyou enable V.13 operationand later disable it, the dataformat does notautomatically revert toasynchronous. To restorethe asynchronous dataformat, you must use theData Format option.

3.15 V.33 and Bell 208A/B OptionsThe following three options areavailable on the modem and areintended only for V.33 or Bell208A/B operation. (For Bell 208operation, see also Satellite Delay,Turnaround Delay, 208 PhaseDetection, Answer Tone Detectionand V.32/208 Auto-Detect Modelater in this chapter.)

Carrier Type

V.33, 208, V.32/208 modes

SWITCHED (SWITCH). For 2-wire applications, the carrier typeoption must be set for switchedcarrier operation.

CONSTANT. Constant, orcontinuous carrier can be usedonly for 4-wire leased lineapplications (although suchapplications may also use switchedcarrier).

CTS

V.33 mode

This option applies only to V.33leased-line applications that useconstant carrier.

RTS. The CTS signal follows RTS.

ON. CTS is always ON.

NOTEThe modem also supports aCTS to EIA option, which isdescribed in Section 3.11.

RTS-CTS Delay (CTS Delay)

V.33, 208, V.32/208 modes

The available RTS-to-CTS delaysettings are 0, 15, 50, or 150 ms.However, the only available choicesfor 208A/B operation are 50 and150 ms. If you select 0 or 15 ms, theactual delay in 208A/B mode willbe 50 ms.

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MODEM 32144

NOTERTS-to-CTS delay is noteffective if the CTS option isset to ON (always ON). ForV.33 operation, RTS-to-CTSdelay is only effective for 4-wire leased line applicationsthat use constant carrier.

RTS-CTS Delay with V.13 Operation

If the V.13 Operation option is setto TX ONLY or TX AND RX, theactual RTS/CTS delay time maydiffer from the selected RTS/CTSDelay setting. The actual RTS/CTSdelay depends on the data rate, asshown in Table 3-2.

Table 3-2. RTS/CTS Delay with V.13 Operation.

Data Rate Delay Setting, msbps

0 15 50 150

Actual Delay, ms

14,400 9 15 50 106

12,000 9 15 50 106

9600 8 15 50 106

7200 6 15 50 106

4800 10 15 50 106

2400 16 16 50 150

1200 29 29 50 150

600 65 65 65 150

67


3.16.1 DIAL LINE OPTIONS

(The numbers used to selectdifferent settings for each optionon the Summary Setup LCD screenare arranged according to optiongroups—dial line options, V.42error-correction options, etc. Fordetails, see Appendix B.)

Wait for Carrier


The time the modem will wait for acarrier signal when originating acall can be set for 30, 45, 60, or 75seconds. (Note: In Hayes mode,the wait-for-carrier time isdetermined by the value in register S7.)

3.16.2 V.42 ERROR-CORRECTIONOPTIONS

Selective Retransmission


This option allows the modem tocommunicate with certain modemsthat are not able to respond to theMNP selective retransmissioncommand.

ENABLE. This setting allows themodem to request retransmissionof a single information frame (inthe event of a transmission error).

DISABLE. Data can beretransmitted only in a series of information frames.

LCD Intensity

All modes

This option allows you to usepushbutton 3 (for INC or increase)to darken characters on the LCDor pushbutton 1 (for DEC ordecrease) to lighten them.

3.16 Options Accessible Only viaSummary SetupThe options described in thissection can only be changedthrough the modem’s SummarySetup feature, which is explainedin Appendix B. For mostapplications, it is not necessary tochange these options—they areintended primarily for specializedapplications. For an explanation ofhow to change these options,available option settings and thedefault setting for each option, seeAppendix B.

Three additional optionsaccessible only via Summary Setupinclude Operating Mode Fallback,Rate Renegotiation Procedure, andSpeed Fallback.

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MODEM 32144

DCE Pass-through Flow Control


This option affects DCE-DTEflow control only. It is effective onlyif error correction or buffer-mode/speed conversion is enabled.

ENABLE. The modem will passflow-control characters receivedfrom the remote modem to thelocal DTE.

DISABLE. The modem will notpass flow control characters fromthe remote modem to the localDTE.

Link Flow Control


This option is effective only ifbuffer-mode/speed conversion isenabled and a buffer link withouterror correction is established. Donot enable Link Flow Control ifbinary data will be transmitted orreceived.

ENABLE. The modem will checkfor X-ON/X-OFF (DC1/DC3) flow-control characters received fromthe remote modem to determinewhether to stop or start/restartdata transmission to the remotemodem. A DC3 control characterwill cause the modem to stop datatransmission and hold data in itsbuffer until it receives a DC1

control character (which instructsthe modem to resumetransmission).

If Link Flow Control is enabledwith DTE-DCE flow control set toRTS on/off and DCE-DTE flowcontrol set to CTS on/off on boththe originating and answeringmodems, and both modemsestablish a buffer-modeconnection, the modems willexchange flow control signalsacross the link in the form of DC1and DC3 characters. If the databeing exchanged contains a DC3character (e.g., binary orexecutable files), this will signal theremote modem to halt and bufferall data from the remote DTE untilthe local DTE sends a DC1character.

DISABLE. The modem willignore XON/XOFF (DC1/DC3)flow -control characters receivedfrom the remote modem.

SLAVED. Link flow control iscontrolled by the DCE-DTE FlowControl option. If DCE-DTE FlowControl is set to NONE or CTS,Link Flow Control is disabled.Otherwise it is enabled.

69


3.16.3 DATA PUMP OPTIONS

Phase Reversal in Answer Tone

All modes

When enabled, the Phase Reversalin Answer Tone option signals thetelephone network to turn off itsecho cancelers. For virtually allapplications, phase reversal shouldbe enabled (the default setting).

Satellite Delay

208, V.32/208 modes

This option facilitatestransmission over satellite links(but does not permit fast-turn-around operation). When theSatellite Delay option is on, RTSis inhibited for 275 ms after theanswer tone stops and after theDSR signal comes on. This delayoccurs at both the originating andanswering modems, allowing theecho suppressors on the telephonelink to be enabled.

Turnaround Delay

208, V.32/208 modes

This option is intended for circuitswhere echo is a problem. It pre-vents the modem from receiving an echo of its own transmitted data.When the Turnaround Delayoption is on, CD (pin 8) is held lowfor 150 ms after RTS is turned off.If the modem detects an energyloss during the delay, it turns CDon 52 ms after detecting the loss. If

the modem does not detect anenergy loss, it turns CD on 52 msafter the end of the delay. Themodem ignores any energy lossduring the first 8.5 ms.

V.32 Mode


This option is used to selectCCITT V.32 bis operation or V.32extended operation.

V.32bis. When V.32bis mode isselected (factory-default setting),the following are available: RateRenegotiation Procedure (RRP), a data rate of 7200 bps, and a RATE screen that allows the user to manually initiate RRP.

RRP enables the modem toautomatically fall back or fallforward to a lower or higher datarate during data transmission inresponse to changes in signalquality. Selecting V.32 bis modemakes RRP available as an option;however, RRP will not functionunless it is enabled. (Enabled is thefactory-default setting.) RRP isdescribed fully in Section 4.3.2.

When V.32 bis mode is selected,a RATE screen is available fromMAIN MENU screen 3. The RATEscreen can be used to manuallyinitiate RRP for diagnosticpurposes. For additionalinformation, see RATE CHANGESCREEN in Section 8.7.

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MODEM 32144

When V.32bis mode is selected,7200 bps can be selected as themaximum or minimum data rate(using the Speed Limit option).When V.32bis is not selected, 7200-bps operation is not available.

NOTEBy definition, V.32 bisoperation includes theability to operate at 12,000and 14,400 bps. However,RRP, the 7200-bps data rate,and the RATE screen areavailable on the modemwhen V.32 bis is selected.

V.32 EXTENDED. V.32 extendedmode disables the V.32 bis features.In V.32 extended mode, themodem’s functionality is identicalto that of modems prior toincorporation of the CCITT V.32bis recommendation.

208 Phase Detection

208, v.32/208 modes

NORMAL. Conditions themodem’s 208 receiver forcompensated modulation detectionfor improved performance witholder 208 modems.

V.22 bis S1 Duration


This option affects the durationof the S1 signal during a V.22 bishandshake. To allow the modem toconnect properly with certain

manufacturers’ V.22 bis modemsthat do not conform fully with theV.22 bis standard, the modem’s S1signal duration may have to bechanged from the default setting,100 ms, to 150 ms. The CCITT V.22bis specification specifies an S1duration of 100 ms.

V.32/208 Auto-Detect Mode

208, V.32/208 modes

To enable V.32/208 auto-detectmode, the V.32/208 auto-detectSummary Setup option must be setto 1 for enable and the front panelSpeed Type option must be set toAUTO. (If you select the V.32/208auto-detect Quick Setup, themodem automatically sets both ofthese options to enable V.32/208auto-detect mode.)

When V.32/208 auto-detectmode is enabled, the modemautomatically selects V.32 or Bell208 mode, depending on the mode of the originating modem.

3.16.4 MISCELLANEOUS OPTIONS

V.25bis DTR Dialing

V.25 bis mode

This option enables or disablesDTR dialing for V.25 bis mode only.If this option is enabled, DTRdialing will function in V.25 bismode—depending on which ofthese modes (i.e., whichautodialer) is enabled.

71


ENABLE. Enables DTR dialing forV.25 bis mode.

DISABLE. Disables DTR dialing forV.25 bis mode.

Analog Loopback Make Busy

All modes

If the Analog Loopback Make Busyoption is enabled, the modem willprovide a busy indication to thedial-line interface when themodem is in analog loopback testmode.

Answer Tone Detection

208, V.32/208 modes

ENABLE. Conditions theoriginating modem’s receiver to wait for answer tone detectionbefore going on-line.

DISABLE. Conditions theoriginating modem to go on-linewithout requiring answer tonedetection. This setting accom-modates operation with automaticcalling units that connect themodem to the line at the end ofanswer tone.

Multimode Handshake


This option determines how longthe modem will attempt to hand-shake with a V.32 modem beforefalling back to a lower speed.

T1 TIMER. If the T1 timersetting is selected, the modem willattempt to handshake with a callingV.32 modem for the time specifiedby the T1 Timer option.

V.32 bis ANNEX A. If the V.32 bisAnnex A setting is selected, themodem will handshake accordingto the conventions established inAnnex A of the CCITT V.32 bisrecommendation. Handshakingusing the Annex A selection willgenerally be faster thanhandshaking based on the T1timer.

Remote RTS Signaling

Leased line modes (except V.33)

This option provides remote RTSsignaling in asynchronous mode.When the Remote RTS Signalingoption is on, the state of the Readyto Send (RTS) signal is transferredacross the modem link (fordiagnostic purposes) withoutaffecting normal operation. TheRemote RTS Signaling optionallows control over the remoteCarrier Detect (CD) signal asdescribed below.

Note the following restrictionsfor Remote RTS Signaling: The twomodems must be connected at adata rate of 7200 bps or higher.The V.13 Operation option must be off. The DTE-DCE and DCE-DTE Flow Control options shouldnot be set to RTS on/off.

72

MODEM 32144

Wait for MNP Link Request

Hayes, V.25 bis (Async only),Dumb, Leased-line modes (except V.33)

When a remote originatingmodem attempts to establish anMNP connection with a modem,the answer modem will wait up to3 seconds, by default, to receivethe MNP link request. This optionallows the user to configure themodem to wait longer (7 seconds)for an MNP link request. Thelonger wait time allows the modemto establish MNP connectionsunder conditions that requiremultiple link requests.

CFI AB Response on Disconnect

V.25 bis

In V.25bis mode, the originatemodem sends a CFI AB result codewhen a call is aborted because theuser has selected HANGUP fromthe front panel or because of DTRloss. If the CFI AB Response onDisconnect option is enabled, theoriginate modem will also send aCFI AB result code upon calldisconnect.

ON. The state of RTS input (EIA pin 4) will be signaled to theremote modem’s CD output, andCD (pin 8) on the local modemwill follow the state of the remotemodem’s RTS input. (The typicalpropagation delay is less than 800ms.)

OFF. This setting allows fornormal operation: The state ofRTS at the local modem will not be signaled to the remote modem.

Leased Line Interrupt

Leased-line modes (except V.33)

The Leased Line Interruptoption controls a modemdesignated as the answer modemand configured for Leased LineAuto-Recovery (Section 4.9) asstated below.

ON. The answer modem willanswer incoming calls, regardless of the state of the leased line (CDON or OFF).

OFF. This setting allows fornormal operation: If CarrierDetect (CD) is ON, this means theleased line is trained and working,and the answer modem will ignoreany incoming calls on the dial line.

73


Low-Profile DIAG LED Function

All modes

This option may be used tochange the function of the DIAGLED on low-profile modems(Appendix D), as explained below.

CONNECT STATUS. DIAG LEDon indicates the modem’sdiagnostic port is activelyconnected. DIAG LED off indicatesthe diagnostic port is notconnected.

DTR STATUS. DIAG LED onindicates DTR is high. DIAG LEDoff indicates DTR is low.

14

MODEM 32144

2.1.2 CONNECTIONS

Fig. 2-1 shows how the modem isconnected to the computer orterminal, power, phone lines, andhandset (optional). Do not installthe modem more than 50 feet (15.2 m) from the DTE. This is the EIA recommended maximumlength for interface cable.For all applications—

• Connect the modem connectormarked “DTE” to the computeror other DTE. Use an EIA RS-232 interface cable (notsupplied with the modem)to make this connection.

• Attach the power transformercable (supplied with themodem) to the modemreceptacle marked “POWER,”and plug the other end into a115-VAC power outlet.

For dialup applications—• Connect the modem to the

telephone line modular walljack, as follows: Use the cable(supplied) that has an eight-pinmodular connector on one endand a six-pin modularconnector on the other. Plugthe eight-pin connector end ofthe cable into the modem jacklabeled “TX DIAL.” Then plugthe six-pin connector end intothe telephone line modularwall jack. Do not bundle thetelephone and EIA interfacecables together.

• Optional: If you want to usethe telephone line for voicetransmissions (when themodem is not operating in data mode) or for manual dial operation, plug a standardtelephone set into the jack inthe rear of the modem labeled“PHONE.”

For leased line applications—• Attach the six-pin modular-

connector end of the four-conductor cable (supplied) tothe modem connector labeled“LEASED LINE.” Attach thespade-lug end of the cable intothe line terminal block.

The same cable is used whetherthe leased line is a 4-wire or 2-wire line. In a 4-wireapplication, the green and redwires are the TRANSMIT pairof wires, and the yellow andblack wires are the RECEIVEpair. When the cable isconnected to a 2-wire line, onlyits green and red wires are used(and the yellow and black wiresshould be cut off).

15


Fig. 2-1. Installation of the Modem.

DTEREAR PANEL LEASED LINE

POWERPHONE

DIAGNOSTICCONNECTOR*

EIA RS-232CINTERFACE CABLE

WITH DB-25CONNECTOR

DATA TERMINALEQUIPMENT

(DTE)

POWERTRANSFORMER

DIALLINE*

LEASEDLINE*

TELEPHONE*(HANDSET)

* NOT REQUIRED FOR ALL APPLICATIONS

2.1.3 JUMPERS

For most applications, you don’tneed to reset internal jumperswitches. However, jumper switchesmust be reset if you need toconnect frame ground to signalground, switch from A/A1 controlto MI/MIC control, or use themodem in a DC rack enclosure.For detailed jumper information,see Appendix C.

16

MODEM 32144

2.2 Front-Panel LCD and ControlsTo select a Quick Setupconfiguration (as explained in thenext section), you will need to usethe pushbuttons and liquid crystaldisplay (LCD) on the modem’sfront panel. These features areshown in Fig. 2-2.

LIQUID CRYSTAL DISPLAY (LCD)

1

PUSHBUTTONS

FRONT PANEL

2 3 ENT1 2 3

Fig. 2-2. Pushbuttons and LCD on the Modem’s Front Panel.

For a detailed explanation of thefront-panel controls, see Chapter 3.

V.32 bis/19.2MVersion 3.02

17


2.2.1 POWER-ON SCREEN

When the modem is powered on,the unit momentarily displays thepower-on screen, which typicallylooks like this:

D=Dial line occupied

R=Ringing (R appears in sameposition as D.)

S=Connection secured by securityhandshake (S appears in the sameposition as D. S and D may flashalternately.)

TR=Data Terminal Ready

MR=Data Set Ready

RS=Request to Send

CS=Clear to Send

TD=Transmit Data

14,400, 9600, 4800, etc.=Data speedin bits per second (“idle” or H-01,H-14, etc. may also be displayed inthe data speed position; see below.)

TM=Test mode

ER=Error (poor signal quality)

CD=Carrier Detect

RD=Receive Data

Codes beginning with “H” (suchas H-01) in the lower left corner ofthe status screen indicate that themodem is handshaking withanother modem (attempting toestablish a connection). When themodem is off-line, the word “idle”is displayed in the same position.

V.32 bis/19.2MVersion 3.02

The numbers displayed in thelower right corner are the revisionlevels of the software used in themodem. The software revisionlevels displayed by your unit may be different than those shownabove. If you need to call TechnicalSupport, please be prepared to givethe support group the softwarerevision levels of your unit.

The modem spends about twoseconds checking the ROMchecksum and doing self-tests andthen displays the EIA status screen.

2.2.2 EIA STATUS SCREEN

The EIA status screen indicates theoperational status of the modem aswell as the condition of certain EIARS-232 leads. The abbreviationsthat may appear are identifiedbelow; however, typically only a few of these abbreviations will bedisplayed during actual operation.

D TR MR RS CD TD9600 TM ER CD RD

18

MODEM 32144

2.3 Quick SetupTo quickly set up the modem for immediate use (or to quicklychange the modem’s configu-ration for an alternate mode of operation), select one of thefactory-preset Quick Setupconfigurations. Select the QuickSetup (Table 1-1) that correspondsto the application you will use.

When you select a Quick Setup,the modem automatically sets all of its options to the settings that are typically most suitable for yourapplication. Selecting a QuickSetup overwrites previously storedoption settings but does not affecttelephone numbers which may bestored in the modem’s memory.

Whether you use a Quick Setupconfiguration “as is” or customize itby changing specific option settings(Chapter 3), you should begin byselecting the Quick Setup thatcorresponds to your application.

2.3.1 HOW TO SELECT A QUICK SETUP

To select (activate) a Quick Setupconfiguration, follow the stepsbelow. As you do, you may find ithelpful to refer to the LCD flowchart that is shipped with themodem.

1. Press the ENT (enter)pushbutton on the modem’sfront panel. Screen 1 of theMAIN MENU will be displayed:

You will only need to press theENT button once if the modem hasjust been powered up. Otherwise,you may have to press the ENTbutton two or more times untilscreen 1 of the MAIN MENU isdisplayed.

[There are two ways to access theQUICK SETUP menu: QUICK maybe selected from the MAIN MENU,as described above, or from screen1 of the SETUP menu. See MAINMENU screen 1 and SETUP menuscreen 1 on the LCD flow chart.]

2. Press pushbutton 2. Screen 1 of the QUICK SETUP menuwill be displayed:

MAIN MENU <1>TALK QUICK DIAL

QUICK SETUP <1>2-W DIAL (HAYES)

3. Move to the QUICK SETUPscreen that shows theconfiguration you want. Usethe right arrow button to movefrom QUICK SETUP screen 1to the QUICK SETUP screenfor the configuration you want.You may also use the left arrowbutton to move “backward”through the QUICK SETUPmenu.

19


There are 15 QUICK SETUPscreens, one for each QuickSetup configuration. For a briefdescription of each QuickSetup configuration, see Table2-1.

4. When the LCD shows theQuick Setup configuration youwant, press pushbutton 2. Thiswill cause the bottom line ofthe display to flash on and off.

5. Press the ENT button twice. Asyou do this, you will see SETUPscreen 1; then—after you pressthe ENT button a second time—the modem will reset. (It is at this point that the selectedQuick Setup actually takeseffect.)

The modem is now set up for the Quick Setup configuration you have selected. All options willbe set as shown in Appendix A. Ifyou want to customize the QuickSetup configuration by changingindividual options, see Chapter 3.For Hayes mode options, see alsoChapter 5.

20

MODEM 32144

Table 2-1. Available Quick Setup Configurations.

Quick Setup as Identified on LCD Description

QUICK SETUP <1> 2-Wire Dial Hayes Emulation Mode—

2-W DIAL (HAYES) This Quick Setup (for communication

over ordinary phone lines) allows the

modem to automatically dial (autodial) a

previously stored phone number and

respond to Hayes commands. This

mode is compatible with communication

software packages that use Hayes™

style “AT” commands. The Hayes

mode Quick Setup is the factory-

default configuration for the modem.

QUICK SETUP <2> 2-Wire Dial V.25 bis Mode,

V25 DIAL (Async) Asynchronous—In V.25 bis mode,

the modem operates in conformance

with CCITT recommendation V.25 bis,

allowing you to store and direct

dial or autodial phone numbers

from the DTE. Use Quick Setup

2 if the DTE connected to the

modem is asynchronous.


V25 DIAL (Syn_c) Synchronous, Character-

Oriented—Same as Quick Setup

2 except for data protocol. Use

Quick Setup 3 if the DTE is

synchronous, character-oriented.

21


Table 2-1. Available Quick Setup Configurations (continued).



V25 DIAL (Syn-b) Synchronous, Bit-Oriented—Same

as Quick Setup 2 except for data

protocol. Use Quick Setup 4 if the

DTE is synchronous, bit-oriented.

QUICK SETUP <5> 2-Wire Dial Dumb Mode—When the

2-W DIAL (DUMB) modem is in Dumb mode, you can use

the modem for dial answer-only

applications, dial a previously stored

telephone number from the front panel,

or dial phone numbers via an external

source (telephone).

QUICK SETUP <6> 2-Wire Leased Line Originate Mode—

2-W LEASED (ORG) In Leased Line mode, the modem

connects to the leased line and stands

ready to send and receive data. Use

Quick Setup 6 if the leased line is a

2-wire line and you want to configure

the modem as the originate modem.

QUICK SETUP <7> 2-Wire Leased Line Answer Mode—

2-W LEASED (ANS) Same as Quick Setup 6 except for

modem answer/originate status. Use

Quick Setup 7 if the leased line is a

2-wire line and you want to configure

the modem as the answer modem.

22

MODEM 32144



QUICK SETUP <8> 4-Wire Leased Line Originate Mode—

4-W LEASED (ORG) Same as Quick Setup 6 except for

line type. Use Quick Setup 8 if the

leased line is a 4-wire line and you want

to configure the modem as the originate

modem.

QUICK SETUP <9> 4-Wire Leased Line Answer Mode—

4-W LEASED (ANS) Same as Quick Setup 6 except for

line type and modem answer/originate

status. Use Quick Setup 9 if the

leased line is a 4-wire line and you

want to configure the modem as the

answer modem.

QUICK SETUP <10> V.33 Leased Line Operation—This

4-WLL V.33 Quick Setup configures the modem

for V.33 operation.

QUICK SETUP <11> 2-Wire Dial Bell 208 Operation—

2-W DIAL (208) This Quick Setup configures the

modem for 2-wire dial operation

compatible with Bell standard 208B.

QUICK SETUP <12> 2-Wire Dial V.32/208 Auto-Detect

2-W DIAL V32/208 Mode—This Quick Setup configures

the modem to automatically select

V.32 or Bell 208 operation, depending

on the mode of the originating modem.

23




QUICK SETUP <13> 4-Wire Leased Line V.29 Mode—

4-WLL V.29 This Quick Setup configures the

modem for V.29 operation, for

compatibility with V.29 modems.

QUICK SETUP <14> V.29 Fast Master Mode—

V.29 FAST MASTER This Quick Setup configures the

modem for V.29 fast train master

operation, for use in a multidrop

network where multiple remote

(slave) modems share the master

modem as the host modem.

QUICK SETUP <15> V.29 Fast Slave Mode—

V.29 FAST SLAVE This Quick Setup configures the

modem for V.29 fast train slave

operation, for use in a multidrop

network where multiple remote (slave)

modems share the same host

(master) modem.

24

MODEM 32144

Table 2-2. Quick Setup Modes Supported.

Quick Setup V.32/19.2M

Hayes (01) Y Y

V.25bis (02-04)

Dumb (05)

Leased (06-09)

V.33 (10) N Y

Bell 208 (11-12) N Y

V.29 (13-15) N Opt.

Y Yes; supported. N No; not supported.

Opt. Optional;

25


2.4 Basic OperationTo assist you in getting the modemup and running, the followingsections provide basic informationfor each of the modem’s primaryoperating modes. For additionaloperating information, refer to theremaining chapters in this manual.

If you encounter difficulty, referto Section 2.4 at the end of thischapter.

2.4.1 2-WIRE DIAL HAYES MODE(QUICK SETUP 1)Two-wire dial Hayes emulationmode is the factory defaultconfiguration for the modem.Hayes mode operation is explainedin detail in Chapter 5.

To dial a telephone number in Hayes mode, type the Hayescommand AT D on your computeror terminal keyboard followed bythe number you want to call. Forexample:

AT D 5551212 [CR]

Dashes or spaces may beincluded for clarity, but they arenot necessary. (The modem willignore them.) A carriage return[CR] or period is required at the end of each command line. (On most keyboards, the carriage-return [CR] key is labeled “Enter”or “Return.”) In response to thecommand line shown above, the modem will dial the number555-1212.

If you have to dial an access code such as 9 to dial out of yourbuilding, insert the access code and a comma in the dial string.

AT D 9,5551212 [CR]

The comma causes the modem to pause for 2 seconds. This allowsthe modem to detect a second dialtone (after the access code) beforedialing the number.

The default dialing mode is pulsedialing. To change to tone dialing,insert a T after AT D: AT DT. Tochange from tone dialing to pulsedialing, insert a P: AT DP. Thespecified dialing mode will remainactive until the alternate mode isspecified or the modem is reset.

When a phone number issuccessfully dialed, a “CONNECT”message will appear on thecomputer screen, and the LCDon the modem will display a statusscreen that typically look like this:

D TR MR RS CS TD9600 CD RDTD and RD will be flashing (to

26

MODEM 32144

indicate that the modem is tran-smitting and receiving data). (Thespeed may be other than 9600 bps;the modem will automaticallyadjust to the speed of the remotemodem, provided the remote unitis a compatible modem.)

To terminate a call, first enter the escape sequence +++. When theOK response appears on the DTEscreen, enter the command AT H.An alternate method is to drop theDTR signal from the DTE. If youare using a computer with acommunication software program,follow the program’s instructionsfor initiating and terminating calls.

2.4.2 2-WIRE DIAL V.25 BIS MODE(QUICK SETUP 2–4)The modem supports three types ofV.25 bis operation—asynchronous;synchronous, character-oriented; orsynchronous, bit oriented. There isa Quick Setup for each V.25 bistype, as shown in Table 2-1. ForV.25 bis operation, the modemmust be configured to use thesame data protocol (asynchronous;synchronous, character-oriented; or synchronous, bit-oriented) asthe attached DTE. If you haveselected the correct V.25 bis QuickSetup, the data protocol will be setautomatically to the correct setting.V.25 bis mode operation andcommands are explained in detail in Chapter 6.

Asynchronous V.25 bis Operation

In asynchronous applications,V.25bis commands (listed inChapter 6) may be entered fromthe DTE keyboard. As an example,the simplest command sequence isCRN 3331234. In response to thiscommand, the modem sends a VALresult code (indicating that thecommand has been accepted),dials the telephone number, 333-1234, and then waits for an answertone from a remote modem. If nocarrier is detected within a giventime (45 seconds by default), themodem automatically releases theline and sends a CFI NT result code.

Spaces entered in the commandline for readability are ignored;therefore, CRN 555 1212 will havethe same effect as CRN5551212.

The data format of the DTEshould be set to 7 data bits witheven parity and one stop bit. (Notethat the default DTE interface rateis 38,400 bps in asynchronousmode.)

When a phone number issuccessfully dialed, the EIA statusscreen on the modem will typicallylook like this:

D TR MR RS CS9600 CD

27


Originating a Call from the FrontPanel

Before you can originate a callfrom the front panel, you muststore the number to be dialed inthe modem.

Storing a Number

From the EIA status screen, accessthe PHONE screen by pressing thefollowing pushbuttons in sequence:

ENTRight arrowPushbutton 1Left arrow 2 timesPushbutton 1

The abbreviations DEC, CTRL,and INC will be displayed on thebottom line of the LCD, indicatingthat you have located the PHONEscreen.

Store the phone number asfollows: Use the right and leftarrow pushbuttons to go to thedigit you want to change. Thecursor will cause the character at that digit location to blink,indicating that the digit orcharacter can be changed. Usepushbutton 1 to decrease numbersand pushbutton 3 to increase them.Use pushbutton 2 (CTRL) tosequence through the dialingcontrol characters (which areexplained in Chapter 4). Use thearrow pushbuttons to move on tothe next digit or character to bechanged. (The characters that can

Synchronous V.25 bis Operation

In synchronous applications, theV.25 bis commands can be used to facilitate computer-controlledoperations. Synchronous bit-oriented operation uses High-Level Data Link Control (HDLC)formatting. In synchronouscharacter-oriented operation,messages are framed by synchro-nous start-of-text and end-of-textcharacters, with the start-of-textcharacter preceded by twosynchronous (SY) characters.

2.4.3 2-WIRE DIAL DUMB MODE(QUICK SETUP 5)Dumb mode is used primarily for manual call origination, andanswer-only applications, and inconjunction with certain dial backsecurity systems that use MI/MICsignals to place the modem on-line.(If you need to configure themodem for MI/MIC use, refer to Appendix C.) For additionalinformation on Dumb mode, refer to Chapter 4.

Answering a Call Automatically

After the Quick Setup for 2-wiredial Dumb mode has been selected,the modem is configured toautomatically answer incomingcalls. The only other requirement isthat the DTE must provide theDTR signal (TR on the EIA statusscreen) to the modem or DTRmust be set to TRUE (using themodem’s DTR from EIA optionscreen).

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MODEM 32144

be stored are listed in Chapter 4.)The phone number is saved whenyou return to the Main Menu. Toreturn to the EIA status screen,press ENT three times.

Autodialing the Stored Number

To autodial the stored numberfrom the EIA status screen, pressthe following pushbuttons insequence:

ENTPushbutton 3 (to select DIALfrom MAIN MENU screen 1)Pushbutton 1 (to select DIALfrom the AUTO-DIAL screen)

When the local modem hassuccessfully established aconnection with the remote unit,the EIA status screen should bepresent. Typically this screen willlook like this:

D TR MR RS CS TD9600 CD RD

If the modem’s LCD displays anAUTO-DIAL FAILURE message,refer to the explanations listedbelow.

Table 2-3. Failure Message and Explanations.

Failure Message Explanation

LINE OCCUPIED The data line is already in use.

DIAL NOT ALLOWED Modem is not configured for dial

backup.

NO DTR DTR is not present.

NO LINE CURR Line current has been lost.

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Terminating a Data Call

Normal termination of a data call isprocessed through communicationsoftware. An alternate method is toswitch to the HANGUP option onthe AUTO-DIAL screen. Anothermethod is to drop the DTR signalfrom the DTE (by software controlor by turning the DTE off).

For manual originate/answeroperation, see Chapter 4.

2.5 Leased Line (2- or 4-Wire) Mode(Quick Setup 6–9)This section does not apply to V.33leased-line operation. For V.33leased-line operation, see the nextsection.

The following informationapplies to both 2-wire and 4-wireleased line operation:

• The modem must beconfigured for the correct linetype—2-wire or 4-wire. If youhave selected the correctLeased Line Quick Setup, the line type will be setautomatically to the correct setting.

• One modem must be set tooriginate mode and the otherto answer mode. If you haveselected the correct LeasedLine Quick Setup, theanswer/originate status will beset automatically to the correctsetting.

• Leased line operation isrestricted to data rates of 4800 bps or higher.

• Lines can be conditioned or unconditioned.

Four different leased-line QuickSetups are available (not countingV.33 leased line operation), asshown in Table 2-1. After you selectthe appropriate leased-line QuickSetup, the answer unit immediatelygenerates an answer tone thatsignals the originate modem tobegin the training sequence,meaning it is ready to “handshake”with the originate modem.

When the local modem hasestablished a connection with theremote unit, the EIA status screenshould be present. Typically thisscreen will look like this:

TR MR RS CS TD9600 CD RD

2.6 V.33 Leased Line Operation (QuickSetup 10)V.33 operation is available on themodem and is restricted to speedsof 12,000 and 14,400 bps.

V.33 leased line operationprovides compatibility with V.33modems (synchronous operationonly).

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MODEM 32144

A 4-wire line must be used(conditioned or unconditioned),and both connected modems mustbe set for V.33 operation.

After the V.33 Leased Line Quick Setup has been selected, the modem immediately begins the training sequence, meaning itis ready to communicate with theother modem. The second modemto come online will automaticallyestablish the data link (regardlessof whether it is the local or remoteunit).

When the local modem hassuccessfully established aconnection with the remote unit,the EIA status screen should bepresent. Typically the screen willlook like this:

2.7 2-Wire Dial Bell 208 Operation(Quick Setup 11–12)The modem supports Bell 208operation. To confirm this, selectSETUP from MAIN MENU screen2. Then select QUICK from SETUPscreen 1. Press the right arrowpushbutton repeatedly to cyclethrough the Quick Setup screens. Ifyou can access the two Quick Setupscreens shown below, the unitsupports Bell 208 operation.

TR MR RS CS TD14.4 CD RD

Three options are intended forV.33 (and Bell 208A/B) operationexclusively. These options are listedin Chapter 3 under the headingV.33 and Bell 208A/B Options.

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2.8 Two Types of Bell 208 OperationTwo Bell 208 Quick Setups areavailable, as shown in Table 2-1.One configures the modem forBell 208 operation, exclusively; the other configures the modemfor V.32/208 auto-detect mode.

2.8.1 BELL 208 OPERATION(EXCLUSIVE)The Quick Setup identified on theLCD as 2-W DIAL (208) configuresthe modem for 2-wire dialsynchronous operation compatiblewith Bell standard 208B. The datarate is fixed at 4800 bps, and thedata format is set to synchronous.Both connected modems must beset for 208B operation.

Beginning with the section titled“Answering a Call Automatically,”all information in Section 2.4.3 alsoapplies to Bell 208 operation.

Fig. 2-3. Quick Setup.

QUICK SETUP <10>2-W DIAL (208)

QUICK SETUP <11>2-W DIAL V32/208

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MODEM 32144

2.8.2 V.32/208 AUTO-SELECT MODE

The Quick Setup identified on theLCD as 2-W DIAL V32/208 (shownabove) configures the modem forV.32/208 auto-detect mode. Thismeans the modem will automati-cally select V.32 or Bell 208 mode,depending on the mode of theoriginating modem. Note that themodem will not handshake in V.22bis, Bell 212/103, or V.21/V.22/V.23 mode when it is configuredfor V.32/208 auto-detect mode.

2.9 4-Wire Leased Line V.29 Mode(Quick Setup 13)The following information appliesto 4-wire leased line V.29 operation:

• The modem must beconfigured for use with a 4-wireline. If you have selected the 4-Wire Leased Line V.29 QuickSetup, the line type will be setautomatically to the correctsetting.

• Operation is restricted to datarates of 4800, 7200, and 9600bps.

• Lines can be conditioned or unconditioned.

After you select the 4-WireLeased Line V.29 Quick Setup, the modem will send a trainingsequence and wait for a trainingresponse from the remote modem.

The modem will repeat the train-ing sequence every 1.2 secondsuntil the remote modem responds.

When the local modem hasestablished a connection with theremote unit, the TIA/EIA statusscreen will be present. Typically,this screen will look like this:


NOTEFor point-to-point 4-wireleased line V.29 operation,the Auto-Retrain optionshould be enabled on bothmodems. (Auto-Retrain isenabled by default if youselect the 4-Wire LeasedLine V.29 Quick Setup.) Ifthe Auto-Retrain option isdisabled, the modem will nottransmit a training sequenceand will instead train on thedata stream from the remotemodem. Disabling Auto-Retrain in 4-wire leased lineV.29 mode is recommendedfor test purposes only. IfAuto-Retrain is disabled, itshould be disabled on bothmodems.

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2.9.1 V.32 DIAL BACKUP

NOTEDial backup can only be usedin point-to-point applications.

To prevent service interruptionin case of poor leased lineconditions, the modem can beconfigured for V.29 leased lineoperation with V.32 dial backup.This means that the modem willuse dial lines to automaticallyrestore operation when conditionson the leased lines deteriorate.(The modem will use V.32modulation for dial backup.) Toset up the modem for V.29 leasedline operation with dial backup,follow these steps:

1. Select the 4-wire leased lineV.29 (4-WLL V.29) Quick Setupon both the local and remotemodem.

2. One modem must be set tooriginate mode and the otherto answer mode. To make thisselection, use the ANS/ORGDEFAULT screen on the frontpanel LCD.

3. Configure the modems forleased line auto-recovery, asexplained in Chapter 4.

2.10 V.29 Fast Master and SlaveModes (Quick Setups 14–15)

NOTEModems used in a V.29 FastMaster and Slave (multidrop)configuration must be modemsthat support V.29 operation.

In multidrop operation (Figure 2-4), the master modem transmits to all of the slave (remote) modems.When the DTE at a slave siterecognizes its own address in thepolling protocol, it raises RTS tothe slave transmitter. The slaveresponds by transmitting a specialtraining sequence, then raisingCTS and transmitting the datafrom the DTE. When the DTE hascompleted transmission, it lowersRTS and the modem will dropcarrier to let the next modem onthe poll list use the channel.

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MODEM 32144

Fig. 2-4. A Typical Multidrop Configuration.

SLAVE-TO-MASTER (INBOUND)TRANSMISSION

When the remote modems comeon-line, they automatically synch-ronize to the incoming carrier andtrain on the data stream from themaster modem. Slave-to-mastertransmission is always switchedcarrier operation under control of the RTS signal from the DTE. An anti-streaming timer built intothe modem will (if enabled) halttransmission if the DTE holds RTSon for more than 30 seconds. Theassumption is that if RTS is held onfor more than 30 seconds, there isa fault in the DTE.

NOTESee page 176 (pump 3)to enable anti-streaming.

The V.29 Fast Master and FastSlave modes support sync data ratesof 4800, 7200, and 9600 bps and anasync data rate of 9600 bps only.The leased lines can be conditionedor unconditioned. The mastermodem must be set to originatemode, and the slave modem must be set to answer mode. (The Answer/Originate option isautomatically set to these settingswhen the V.29 Fast Master and FastSlave Quick Setups are used.)

NOTEIf you’re using V.29master/slave async in anunmanned location, callBlack Box Tech Support at724-746-5500.

35


If you access the TIA/EIA statusscreen on the LCD display when aslave modem is transmitting to themaster modem, the status screenwill typically look like this:


Typically, TD, CD, and RD willflash on the master modem, andRS, CS, TD, and RD will flash onthe slave modem.

2.11 If You Have ProblemsIf you encounter difficulties insetting up or using the modem, trythe remedies described below. Ifyou suspect a system malfunction,follow the diagnostic proceduresdescribed in Chapter 7. If youcannot resolve the problem, callTechnical Support.

2.11.1 ALL MODES

Make sure all cables are properlyconnected to the back of themodem.

2.11.2 ALL DIAL MODES (HAYES, V.25BIS, DUMB, BELL 208, AND V.32/208)DTR (Data Terminal Ready) mustbe ON (received from DTE, orDTR from EIA option set to TRUE)if you want to use the modem’sautodial or auto-answer features. (If DTR is ON, the TR indicatorwill be present on the EIA statusscreen.

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MODEM 32144

2.11.4 HAYES MODE

In Hayes mode, with defaultsettings in effect, the modemtransmits result codes (messages)to the DTE. In some installations,this may cause undesirableinteraction with the attached DTE.If such interaction occurs, resultcodes for incoming calls should besuppressed (using the commandAT Q2).

2.11.3 ALL ASYNCHRONOUS MODES

The modem’s default DTE speed is38,400 bps in asynchronous mode.If the local DTE does not supportthis speed, change the modem’sDTE Speed option setting. InHayes mode, the default DTEspeed is automatically overriddenwhen the modem is autobauded(when the Hayes mode “AT”attention code is sent to themodem).

37


2.11.5 ALL LEASED-LINE MODES(2-WIRE, 4-WIRE, V.33, AND V.29)DTR (Data Terminal Ready) mustbe ON for the units to train on theleased line. (If DTR is ON, the TRindicator will be present on the EIAstatus screen.)

If the signal quality appears to be inadequate (see Section 7.6.2)or if the modems are frequentlyretraining, try changing theequalization option.

2.11.6 LEASED LINE (EXCLUDING V.33AND V.29 OPERATION)Make sure one modem has beenset to originate mode and that theother has been set to answer mode.(If the correct Quick Setup hasbeen selected, and not incorrectlymodified, the answer/originatestatus should be correct.)

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CHAPTER 1: Specifications

Table 1-1. Pin Assignments—EIA Interface Connector

Pin Designation Function LCD Indicator Source

1 AA Frame ground—not connected

2 BA Transmit (send) data (TD) TD DTE

3 BB Received data (RD) RD Modem

4 CA Request to send (RTS) RS DTE

5 CB Clear to send (CTS) CS Modem

6 CC Data set (modem) ready (DSR) MR Modem

7 AB Signal ground (SG) Ground

8 CF Carrier detect (CD) CD Modem

9 +P Testing voltage, +10V Modem

10 -P Testing voltage, -10V Modem

15 DB Transmit clock (TC) Modem

17 DD Receive clock (RC) Modem

18 CN Analog loopback control (ALBT) DTE

20 CD Data terminal ready (DTR) TR DTE

21 CN Remote digital loopback control DTE

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MODEM 32144

Table 1-1. Pin Assignments—EIA Interface Connector (continued)

Pin Designation Function LCD Indicator Source

22 CE Ring indicator (RI) R Modem

23 CH Speed select DTE

24 DA External transmit clock DTE

25 CN Test mode indicator (TM) TM Modem

2

INSTRUCCIONES DE SEGURIDAD

NORMAS OFICIALES MEXICANAS (NOM)

ELECTRICAL SAFETY STATEMENT


1. Todas las instrucciones de seguridad y operación deberán ser leídasantes de que el aparato eléctrico sea operado.

2. Las instrucciones de seguridad y operación deberán ser guardadaspara referencia futura.

3. Todas las advertencias en el aparato eléctrico y en sus instrucciones de operación deben ser respetadas.

4. Todas las instrucciones de operación y uso deben ser seguidas.

5. El aparato eléctrico no deberá ser usado cerca del agua—por ejemplo,cerca de la tina de baño, lavabo, sótano mojado o cerca de unaalberca, etc.

6. El aparato eléctrico debe ser usado únicamente con carritos opedestales que sean recomendados por el fabricante.

7. El aparato eléctrico debe ser montado a la pared o al techo sólo como sea recomendado por el fabricante.

8. Servicio—El usuario no debe intentar dar servicio al equipo eléctricomás allá a lo descrito en las instrucciones de operación. Todo otroservicio deberá ser referido a personal de servicio calificado.

9. El aparato eléctrico debe ser situado de tal manera que su posición nointerfiera su uso. La colocación del aparato eléctrico sobre una cama,sofá, alfombra o superficie similar puede bloquea la ventilación, no sedebe colocar en libreros o gabinetes que impidan el flujo de aire porlos orificios de ventilación.

10. El equipo eléctrico deber ser situado fuera del alcance de fuentes de calor como radiadores, registros de calor, estufas u otros aparatos(incluyendo amplificadores) que producen calor.

3


11. El aparato eléctrico deberá ser connectado a una fuente de poder sólodel tipo descrito en el instructivo de operación, o como se indique enel aparato.

12. Precaución debe ser tomada de tal manera que la tierra fisica y lapolarización del equipo no sea eliminada.

13. Los cables de la fuente de poder deben ser guiados de tal manera queno sean pisados ni pellizcados por objetos colocados sobre o contraellos, poniendo particular atención a los contactos y receptáculosdonde salen del aparato.

14. El equipo eléctrico debe ser limpiado únicamente de acuerdo a las recomendaciones del fabricante.

15. En caso de existir, una antena externa deberá ser localizada lejos de las lineas de energia.

16. El cable de corriente deberá ser desconectado del cuando el equipono sea usado por un largo periodo de tiempo.

17. Cuidado debe ser tomado de tal manera que objectos liquidos no sean derramados sobre la cubierta u orificios de ventilación.

18. Servicio por personal calificado deberá ser provisto cuando:

A: El cable de poder o el contacto ha sido dañado; u

B: Objectos han caído o líquido ha sido derramado dentro del aparato; o

C: El aparato ha sido expuesto a la lluvia; o

D: El aparato parece no operar normalmente o muestra un cambio en su desempeño; o

E: El aparato ha sido tirado o su cubierta ha sido dañada.

4

TRADEMARKS

TRADEMARKS

All applied-for and registered trademarks are the property of theirrespective owners.

CUSTOMERSUPPORT

INFORMATION

Order toll-free in the U.S. 24 hours, 7 A.M. Monday to midnight Friday: 877-877-BBOXFREE technical support, 24 hours a day, 7 days a week: Call 724-746-5500 or fax 724-746-0746Mail order: Black Box Corporation, 1000 Park Drive, Lawrence, PA 15055-1018Web site: www.blackbox.com • E-mail: [email protected]

DECEMBER 1999MD833A-R5

MD833AE-R5MD833C-R5

MD833A-D12MD833A-D24MD833A-D48

Modem 32144Modem 32144 Card

MODEM 32144

➝

➝1

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ENT

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