isdn to v24 converter

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Descri tionConverter ISDN/V.24 3CR 31036 BAAA DEAFA 1/17

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Thales Rail Signalling Solutions GmbH

File: 3CR_31036_BAAA_DEAFA_01.doc

01 25.10.07 TS/AEE, R.Klemm TS/EH, K.Oldewurtel

Rev. Date MTNR STEK, VSB Checked



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Revisions and change reasons

Rev. Date VSB Change reason

01 25.10.07 Klemm Translation from 3CR 31036 BAAA DEAFC Rev. 01



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Contents

1 INTRODUCTION........................................................................................................................... 5

1.1 Scope .......................................................................................................................................5

1.2 General ....................................................................................................................................5

1.3 Abbreviations .......................................................................................................................... 5

2 MECHANICAL FEATURES ............................................................................................................ 6

2.1 Housing.....................................................................................................................................6

2.2 Position of clamps and LEDs..................................................................................................6

3 ELECTRICAL FEATURES ................................................................................................................ 7

3.1 Power supply ........................................................................................................................... 7

3.1.1 Connections .................................................................................................................... 7

3.1.2 LED displays...................................................................................................................... 7

3.2 Data transmission (ISDN)........................................................................................................8

3.2.1 Distance ........................................................................................................................... 8

3.2.2 Connections .................................................................................................................... 8

3.2.3 LED displays...................................................................................................................... 8

3.3 Interface (V.24) ....................................................................................................................... 9

3.3.1 Maximum cable length..................................................................................................9

3.3.2 Connections .................................................................................................................... 9

3.3.3 LED displays...................................................................................................................... 9

3.4 Remote power supply ..........................................................................................................10

3.4.1 Connections ..................................................................................................................10

3.4.2 LED displays....................................................................................................................10

3.5 Air and creeping distances, test voltage..........................................................................10

4 BLOCK DIAGRAM..................................................................................................................... 11

5 OPERATION............................................................................................................................... 11

5.1 Properties of ISDN .................................................................................................................11

5.2 Variants of the converter.....................................................................................................11

5.3 Sample applications of the converter ..............................................................................12

5.3.1 Connection of Detection Points to a transmission system......................................12

5.3.1.1 Converter with one Detection Point (locally fed) ............................................12

5.3.1.2 Converter with two Detection Point (DP 1 fed via data line).........................14

5.3.2 Connection of an ACE to a transmission system...................................................... 15



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5.3.3 Repeater ........................................................................................................................16

5.3.3.1 Repeater with local power supply ..................................................................... 16

5.3.3.2 Repeater fed via data line from ACE ................................................................17



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1 INTRODUCTION

1.1 Scope

This document describes the printed circuit boards Converter ISDN/V.24 with the followingpart numbers:

Part number Item variants

3CR 31036 BAAA Converter ISDN/V24, LT/LT

3CR 31036 BBAA Converter ISDN/V24, NT/LT

3CR 31036 BCAA Converter ISDN/V24, LT/NT

3CR 31036 BDAA Converter ISDN/V24, NT/NT

1.2 General

The converter changes the physical protocol from ISDN signals (2B1Q Coding) to V.24 andvice versa. Two independent ISDN channels are implemented which are configured in thefour different item variants in all combinations of the ISDN modes (LT or NT). Each ISDNchannel offers two V.24 channels B1 and B2.The converter can be supplied from an external power supply voltage or via one of thedata lines.The housing is created for top hat rail mounting.

1.3 Abbreviations

2B1Q Coding mode of ISDN

AC Alternating currentACE Axle Counter EvaluatorCCITT Comité Consultatif International Téléfonique e TélégraphiqueCTS Clear to sendDSR Data set readyDTR Data terminal readyEAK Elektronic-Junction-BoxGND GroundISDN Integrated Services Digital NetworkLED Light emitting diodeLT Line Termination mode of ISDN

NT Network Termination mode of ISDNRTS Request to sendRXD Receive dataTXD Transmit dataV.24 Physical protocol according to CCITT



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2 MECHANICAL FEATURES

2.1 Housing

Dimensions (HxWxD): 50 x 128 x 215 mm3

Weight: appr. 800 grMounting: at 35 mm top hat rail

2.2 Position of clamps and LEDs

Remark: The switches LT/NT are soldered in different positions at the four item variants andmust not be changed.

C h a

nn el 1

C h a n n

e l 2

+ + - -

+ -

+ -

T X 1

R X 1

T X 2

R X 2

a

b

E a r t h

2

a

b

E ar t h 1

T X 1 R X 1

T X 2 R X 2

POWER

N T L T

N T

L T

B 1

B 2

B 1

B 2

Earthingfor overvoltage protection

ISDN-Line

Remote power

supply

Earthingfor overvoltage protection

ISDN-Line

Remote power

supply

Data (Channel 1, B1)

TXD1RXD1GND


TXD2RXD2GND


TXD1RXD1GND


TXD2RXD2GND

Power supply(48 ... 120 VDC)

Power supply(48 ... 120 VDC)



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3 ELECTRICAL FEATURES

3.1 Power supply

An insulated switching power supply is integrated.Voltage range: 48 VDC ... 120 VDC –10%, +5%Fuse: T 1,6 APower consumption: max. 2,5 Watt

3.1.1 Connections

The connections for power supply are using clamp terminals (cross section: 0,08 mm2 to2,5 mm2).Two parallel double clamps are available:

Name at block with 2 clamps Signal

+ Positive supply voltage – Negative supply voltage

3.1.2 LED displays

In the center of the converter there is a green LED which shows the presence of the inputvoltage for power supply.



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3.2 Data transmission (ISDN)

Required wires: 2Data rate: max. 19,2 kBd (asynchronious)Coding: ISDN 2B1Q

Attenuation: max. 24 dB (at 40 kHz)

3.2.1 Distance

The maximum distance for data transmission depends from the attenuation of the com-munication path which must not exceed 24 dB (at 40 kHz) including all cables, clampsand transformers.

Typical attenuation (at 40kHz):

Copper diameter Attenuation Maximum distance (without transformers)

0,9 mm 2,6 dB/km 9,2 km

1,4 mm 2,0 dB/km 12 km

3.2.2 Connections

Clamp terminals (cross section: 0,08 mm2 to 2,5 mm2) are used.In each channel the following clamps are available:

Name at block with 4 clamps Signal

A ISDN line a

+ Positive remote power supply voltage

– Negative remote power supply voltageB ISDN line b

3.2.3 LED displays

The LEDs „Ltg1 OK“ and „Ltg2 OK“ are showing that the ISDN connection of the accordingISDN line is established. Only then data transmission is possible.



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3.3 Interface (V.24)

The bidirectional data of the ISDN line are converted to TxD and RxD signals according toCCITT V.24. The signals at the V.24 interface can be connected directly to a PC. They alsocan be connected crosswise to the other channel to realize a repeater.

Data rate: max. 19,2 kBit/s

3.3.1 Maximum cable length

The maximum cable length must not exceed 10 m.

3.3.2 Connections


Name at block B1(6 clamps) Signal

(not named) Ground (GND)(not named) Not used

TX1 TxD 1 (B1), input

RX1 RxD1 (B1), output

(not named) Not used

(not named) Ground (GND)

Name at block B2(6 clamps) Signal


(not named) Not used

TX2 TxD 2 (B2), input

RX2 RxD2 (B2), output(not named) Not used


Remark:The clamps which are not used may be used to connect additional wires in off the shelfcables. Especially hardware handshake connections may be realized (for example theloops between DTR-DSR and CTS-RTS).

3.3.3 LED displays

Behind the clamps TXx und RXx there are LEDs which are showing the logical state of the

interface.

RX-LED (green):LED Logical state Voltage at the clamp

„on“ High –3...-15 Volt

„off“ Low +3...+15 Volt

TX -LED (yellow):LED Logical state Voltage at the clamp

„on“ High –3...-15 Volt



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„off“ Low +3...+15 Volt

3.4 Remote power supply

Via the transformer at the converter a remote power supply voltage can be send (to sup-

ply a Detection Pont) or received (to supply the converter) via the ISDN line.

Max. voltage: 120 VDC +5%Integrated fuse: 315 mA, plugableMax. overvoltage (against earth): 250 V (peek current 4500 A, 8/20 µs)

3.4.1 Connections


Name at block with 4 clamps SignalA ISDN line a

+ Positive remote power supply voltage

– Negative remote power supply voltage

B ISDN line b

Name Signal

ERDE x Earth contact for overvoltage protection

ERDE x Earth contact for overvoltage protection

3.4.2 LED displays

Behind the clamps for remote power supply there are two red LEDs. Depending on thepolarity one of the LEDs is on if the fuse is broken.This function only works if the remote power supply voltage and the load are still con-nected.

3.5 Air and creeping distances, test voltage

Air andcreeping dis-

tances

Voltage ÛÛÛÛ 11,2/50 µµµµs

Test voltage50 Hz

Power supply – Electronic ≥ 3,6 mm 2,75 kV 1,5 kVeff Power supply – ISDN line ≥ 3,6 mm 2,75 kV 1,5 kVeff

Electronic – ISDN line ≥ 3,6 mm 2,75 kV 1,5 kVeff

ISDN line – ISDN line ≥ 4,0 mm 3,1 kV 1,7 kVeff

The earthing contacts (ERDE1 and ERDE2) for overvoltage protection are separated foreach ISDN line and belong to the ISDN line from the point of view of insulation coordina-tion.



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4 BLOCK DIAGRAM

5 OPERATION

5.1 Properties of ISDN

ISDN is a point to point connection. At both ends of the line one subscriber is connectedonly. The connection with more than one subscriber at one end of the line is not allowedand leads to a fault.After the switch on of the power the line becomes calibrated from both subscribers.

Therefore one subscriber has to be configured as “LT” (like a Detection Point) or “NT” (likean ACE).When the calibration is finished (3..5 seconds) the line is used for data communication.If the calibration is nit successful it is repeated every 15 seconds.

5.2 Variants of the converter

The four variants of the converter allow the universal use.

ISDN

Module

ISDNChannel 1

ISDNChannel 2

B1B1

B2B2

TTL

V.24

TTL

V.24TTL

V.24

TTL

V.24

DC (5V)

DC (48..120 V)

a

b

+-

Earth1

a

b

+-

Earth2

+-

+-

TX1

RX1

TX2

RX2

TX1

RX1

TX2

RX2

Insulation

LT/NT LT/NTGND GND



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In an application it is necessary to use the correct variant of the converter which is de-pendant from the mode of operation (LT or NT) in each ISDN channel. The mode of opera-tion can not be changed.

5.3 Sample applications of the converter5.3.1 Connection of Detection Points to a transmission system

With this application the data of a Detection Point can be connected via the V.24 inter-face to a transmission system and transmitted to an ACE. The converter is locally supplied.Optional the Detection Point can be fed via the data line.On AC electrified lines the maximum continuous induced voltage has to be regarded. Ifnecessary transformers have to be used.

5.3.1.1 Converter with one Detection Point (locally fed)

Variants:Part number Name



Channel 1

C h a n n e l 2

+

+

-

-

+ -

+ - T X 1 R X 1 T X 2 R X 2 a b E a r t h 2

abEarth 1 TX1 RX1 TX2 RX2

P O W E R

NTLTB1 B2

B 1 B 2 N T L T

to Detection Point 1

RXDTXDGND

to power supply(48 .. 120 Volt)

to transmission systemchannel 1 (V.24, 9600 Bd)



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5.3.1.2 Converter with two Detection Point (DP 1 fed via data line)

Variant:Part number Name


Channel 1

C h a n n e l 2

+

+

-

-

+ -



P O W E R

NTLTB1 B2

B 1 B 2 N T L T



RXDTXDGND




RXDTXDGND



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5.3.2 Connection of an ACE to a transmission system

With this application the ACE can be connected via the V.24 interface to a transmissionsystem to receive data from a Detection Point. The converter is locally supplied.On AC electrified lines the maximum continuous induced voltage has to be regarded. Ifnecessary transformers have to be used.


3CR 31036 BAAA Converter ISDN/V24, LT/LT

Channel 1

C h a n n e l 2

+

+

-

-

+ -



P O

W E R

NTLTB1 B2

B 1 B 2 N T L T

to ACE

to ACE

RXD

TXDGND




RXDTXDGND



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5.3.3 Repeater

With the repeater function the ISDN signals become refreshed to double the maximumtransmission distance (dependant from the attenuation of the cable).Auch hier kann zwischen einer direkten Speisung vor Ort und der Fernspeisung über dieISDN Leitung gewählt werden.

On AC electrified lines the maximum continuous induced voltage has to be regarded. Ifnecessary transformers have to be used.

5.3.3.1 Repeater with local power supply



Channel 1

C h a n n e l 2

+

+

-

-

+ -


abEarth 1 TX1 RX1 TX2RX2

P O

W E R

NTLTB1 B2

B 1 B 2 N T L T


to Detection Point

to ACE



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5.3.3.2 Repeater fed via data line from ACE



Channel 1

C h a n n e l 2

+

+

-

-

+ -


abEarth 1 TX1 RX1 TX2RX2

P O W E R

NTLTB1 B2

B 1 B 2 N T L T

to Detection Point

to ACE

isdn to v24 converter

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