7 - geh-6370 mk v time synchronization

8/10/2019 7 - GEH-6370 MK v Time Synchronization

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GEH-6370

SPEEDTRONIC

Mark V

Turbine Control

Time Synchronization


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SPEEDTRONIC

Mark V

Turbine Control

Time Synchronization

GEH-6370

Issue Date: June 1996

These instructions do not purpor t to cover all detail s or vari ations in equipment, nor to provide for every possibl e

contingency to be met duri ng installati on, operation, and maintenance. If fu rther inf ormation is desir ed or if parti cular

probl ems ari se that are not covered suf f icientl y for the purchaser s purpose, the matter shoul d be referred to GE

Industri al Systems.

This document contains propri etary information of General El ectri c Company, USA and i s furn ished to its customer

solely to assist that customer in the install ation, testing, operati on, and/or maintenance of the equipment described. This

document shall not be reproduced in whole or i n part nor shall its contents be disclosed to any thi rd party without the

wri tten approval of GE Industri al Systems.


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1996 by General Electric Company, USA.

All rights reserved.

Printed in the United States of America.

ARCNET is a registered trademark of Datapoint Corporation.

Ethernet is a registered trademark of Xerox Corporation.

SpeedTronic is a registered trademark of General Electric Company, USA.


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GEH-6370 Mark V Time Synchronization

a

SAFETY SYMBOL LEGEND

Indicates a procedure, practice, condition, or statement that, if not strictly observed, could result in

personal injury or death.

Indicates a procedure, practice, condition, or statement which, if not strictly observed, could result in

damage to or destruction of equipment.

NOTE

Indicates an essential operation or important procedure, practice, condition, or statement.

CAUTION

WARNING


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b

This equipment contains a potential hazard of electric shock or burn. Only personnel who are adequately

trained and thoroughly familiar with the equipment and the instructions should install, operate, or maintain

this equipment.

Isolation of test equipment from the equipment under test presents potential electrical hazards. If the test

equipment cannot be grounded to the equipment under test, the test equipments case must be shielded to

prevent contact by personnel.

To minimize hazard of electrical shock or burn, approved grounding practices and procedures must be

strictly followed.

To prevent personal injury or equipment damage caused by equipment malfunction, only adequately trained

personnel should modify any programmable machine.

WARNING

WARNING


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Mark V Time Synchronization GEH-6370

i

TABLE OF CONTENTS

Section/Subject Page

CHAPTER 1. OVERVIEW

1-1.

Introduction.................................................................................................................................................................... 1

1-2. Time Synchronization Features......................................................................................................................................

1

1-2.1. Time Signal Sources....................................................................................................................................................

1

1-2.2. General

Architecture.................................................................................................................................................... 1

1-2.3. Backup Synchronization..............................................................................................................................................

21-3. Manual

Organization...................................................................................................................................................... 2

1-4. Related Documents.........................................................................................................................................................

3

CHAPTER 2. TIME SYNCHRONIZATION THEORY

2-1.

Introduction..................................................................................................................................................................... 5

2-2. Timesync Protocol..........................................................................................................................................................

5

2-3. SupportedGTSs.............................................................................................................................................................. 5

CHAPTER 3. HARDWARE SETUP

3-1.

Introduction.................................................................................................................................................................... 7

3-2. Board Installation...........................................................................................................................................................

7

3-3. Setting Base I/O Address................................................................................................................................................

7

3-4. Setting the

IRQ............................................................................................................................................................... 83-5. Connecting the GTS to the Board...................................................................................................................................

8

3-6. Connecting the 's or 's........................................................................................................................................

9

CHAPTER 4. SOFTWARE SETUP

4-1.

Introduction..................................................................................................................................................................... 11

4-2. Timesync

Datafile........................................................................................................................................................... 11


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ii

4-3. File

Configuration........................................................................................................................................................... 11

CHAPTER 5. LOCAL TIME VS. UTC CONSIDERATIONS

5-1.

Introduction..................................................................................................................................................................... 15

5-2. Internal Time

Reference.................................................................................................................................................. 15

5-3. GTS is UTC (non-changing standard time)

.................................................................................................................... 15

5-4. GTS is Local (changes twice per year) ...........................................................................................................................

15

CHAPTER 6. TIMESYNC OPERATIONS

6-1.

Introduction..................................................................................................................................................................... 17

6-2. GeneralOperations.......................................................................................................................................................... 17

6-3. Using the TIMEUTIL

Program......... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . 18

6-3.1. Turning the TIMESYNC Function Off.........................................................................................................................

18


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iii

Section/Subject Page

6-3.2. Turning the TIMESYNC Function Back On ...............................................................................................................

18

6-3.3. Loading MAJORTIME into the bc620AT Board.........................................................................................................

18

CHAPTER 7. DIAGNOSTICS AND TROUBLESHOOTING

7-1.

Introduction..................................................................................................................................................................... 19

7-2. Obtaining General Information About the Mark V Timesync Function.........................................................................

19

7-3. Other Timesync Diagnostic Capabilities.........................................................................................................................

21

CHAPTER 8. EXAMPLE TIMESYNC CONFIGURATIONS

8-1. Example 1 Using a Single as the Global Time Source..........................................................................................23

8-2. Example 2 Using IRIG-B Timecode as the GTS with Multiple Stagelink........ ...... ...... ....... ...... ...... ....... ...... ...... ..

24

Time Masters and Multiple / Stagelinks

8-3. Example 3 Using Pulse Inputs as the GTS with Multiple Stagelink......................................................................

26

Time Masters and Multiple / Stagelinks

APPENDIX A. GLOSSARY OF TERMS

APPENDIX B. IRIG NOMENCLATURE

LIST OF FIGURES

Figure Page

Figure 1-1. Typical Time Synchronization Architecture........................................................................................................

2

Figure 3-1. bc620AT Time and Frequency Module...............................................................................................................

7

Figure 3-2. SW1 Base I/O Address switch selections.............................................................................................................

8

Figure 3-3. IRQ selection on bc620AT board.... ...................................................................................................................

8

Figure 3-4. 15 Pin D to BNC Adapter....................................................................................................................................

9

Figure 4-1. Timesync Configuration lines in F:\TIMESYNC.DAT.......................................................................................

11

Figure 4-2. Sample

F:\TIMESYNC.DAT............................................................................................................................... 12

Figure 7-1. Sample output from TIMEUTILSTATUS..........................................................................................................

20


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iv

Figure 7-2. Sample output from TS_DUMP...........................................................................................................................

22

Figure 8-1. Typical Layout forFLYWHEELING Timesync Mode........................................................................................

24

Figure 8-2. Typical Layout for External IRIG-B GTS, using redundancy and multiple Stagelink Networks........ ...... ...... ....

25

Figure 8-3. Typical Layout for External 1PPM or 1PPH GTS, with Redundant......... ....... ...... ...... ...... ...... ...... ...... ...... ...... ....27

Stagelink Time Masters and Multiple Stagelink Networks


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Chapter 1, Overview 1

CHAPTER 1

OVERVIEW

1-1. INTRODUCTION

The Time Synchronization option for SpeedTronic Mark V control systems synchronizes all Mark V control panels on

the stagelink to a Global Time Source (GTS) with a limited loss of accuracy. In addition, this option sets all and/or

interface computer timeclocks to the GTS. It is recommended that the remaining plant equipment, including DCSs

(Distributed Control Systems), synchronize to this common GTS.

If assistance is needed, contact:

GE Motors & Industrial Systems

Product Service Engineering, Rm. 191

1501 Roanoke Blvd.

Salem, VA 24153 - 6492 USAPhone 001-540-387-7595

Fax 001-540-387-8606

1-2. TIME SYNCHRONIZATION FEATURES

1-2.1. Time Signal Sources

Mark V Time Synchronization supports several GTSs.

Timecode signals supported (see section 2-3 for details):

IRIG-A IRIG-B

NASA-36

2137

Supported GTSs that use periodic pulses (see section 2-3 for details):

1 PPS

1 PPM

1 PPH

Typical GTSs are GPS (Global Positioning Satellite) receivers such as the StarTime GPS Clock, or other time processing

hardware. The preferred time sources are UTC (Universal Time Coordinated) or GPS. However, the Time Synchronizationoption also supports a GTS using local time as its base time reference. See chapter 5,Local Time vs. UTC Considerations,

for more details.

Chapter 4, Software Setup,discusses the setup for specifying local or global.

1-2.2. General Architecture

The GTS supplies a time link network to one or more or interface computers. Special time/frequency processor

boards such as the bc620AT board are placed in these computers. These boards acquire time from the GTS with a high

degree of accuracy. When the computers receive the time signal, it is sent to the Mark V control panels using a special


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Chapter 1, Overview2

purpose Stagelink Timesync protocol. This protocol minimizes time losses. Figure 1-1 shows a general plant-wide time

synchronization setup.

MK V MK V MK V MK V

TODCS EQUIPMENT

* * *

STAGE LINK

COMMON TIME REFERENCE BUS

TIME LINK

*O tional

TERMINATION

RESISTOR

GLOBAL

TIME SOURCE

TERMINATION

RESISTOR

Figure 1-1. Typical Time Synchronization Architecture

1-2.3. Backup Synchronization

Redundancyprovides backup time synchronization. Supplying time/frequency processor boards to two or more or

computers is redundant. Not all s and s require these boards. Those 's or 's that do not contain

time/frequency processor boards do not attempt to send time to the Mark V. Instead, they become time slaves to the selectedStagelink Time Master in the same way that all Mark V panels are time slaves. The Stagelink Time Master is the common

or selected by all other equipment on the stagelink as the official time source. Failure of this source results in all

time slaves selecting another (but common) or as the new Stagelink Time Master.

1-3. MANUAL ORGANIZATION

This manual is organized as follows:

Chapter 1 Overview

This chapter describes Mark V Time Synchronization and its function. An overview of this manual, as well as related

publications are also presented in this chapter.

Chapter 2 Basic Theory of Mark V Time Synchronization

This chapter describes how Mark V Time Synchronization works and the logic that runs the system. An overview of

supported GTSs is given in this chapter.

Chapter 3 Hardware Setup

This chapter describes how to set up the Mark V Time Synchronization hardware.


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Chapter 1, Overview 3

Chapter 4 Software Setup and Configuration

This chapter describes how to configure the software to run Mark V Time Synchronization.

Chapter 5 Local vs. UTC Considerations

The significance of local and UTC designations are discussed in this chapter.

Chapter 6 General Timesync OperationsThis chapter explains some general operations of Mark V Time Synchronization. Use of the TIMEUTILprogram is

described here.

Chapter 7 Diagnostics and Troubleshooting

This chapter discusses how to get general information from Mark V Time Synchronization. Other ways to diagnose

problems with the Mark V Time Synchronization are explained here.

Chapter 8 Example Timesync Configurations

Three examples of possible Mark V Time Synchronization setups are discussed in this chapter.

Appendix A Glossary of Terms

Defines acronyms and terms used in this manual.

Appendix B IRIG Nomenclature

Defines the nomenclature for standard IRIG Time Codes.

Refer to the Table of Contents for the organization of these chapters.

1-4. RELATED DOCUMENTS

GE Industrial Systems provides the applicable documents to customers as needed to support equipment it supplies. For

documentation that covers equipment from other companies, contact the applicable manufacturer.

GE Publications:

GEH-5979 SPEEDTRONIC Mark V Turbine Control Users Manual

GEH-5980 SPEEDTRONIC Mark V Turbine Control Maintenance Manual

GEH-6195 SPEEDTRONIC Mark V Turbine Control Applications Manual

GEH-6123 SPEEDTRONIC Mark V Turbine Control Historian Maintenance Guide and Users Manual

Handbook of Time Code Formats, 1987, Datum Inc.

bc620AT Time and Frequency Module, Operation and Technical Manual,1994, Datum Inc. Bancomm Div.


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Chapter 1, Overview4

Notes:


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Chapter 2, Time Synchronization Theory 5

CHAPTER 2

TIME SYNCHRONIZATION THEORY

2-1. INTRODUCTION

This chapter explains the basic theory of synchronizing Mark V time to the GTS. Selection of the Stagelink Time Master is

discussed in this chapter, as well as supported GTSs.

2-2. TIMESYNC PROTOCOL

The bc620AT Time and Frequency Module gets time for one or more or interface computers with a high degree of

accuracy. Time is then sent to each Mark V and or time slave using an internal Stagelink Timesync protocol.

This protocol is specifically designed to minimize the loss of accuracy in the time slaves.

Each or with a bc620AT board is an available Stagelink Time Master. Each available Stagelink Time Master

periodically broadcasts an identification message to all time slaves. Each time slave collects the list of available Stagelink

Time Masters and selects the same node for its time reference. Periodically, each time slave asks for the current global

time, noting at the same instant, what local time it has. The Stagelink Time Master notes the global time at the instant the

request for time is received. Next, the Stagelink Time Master returns the recorded global time. The time slave computes the

difference between the returned time and the recorded time of request and adjusts its internal time accordingly.

Local Time is used for display of real-time data. This is done by adding a local time correction to UTC. A node's internal

time clock is normally Global rather than Local. This is done because global time steadily increases at a constant rate, while

corrections are allowed to local time. Historical data is stored with Global time to minimize discontinuities. See Chapter 5,

Local Time vs. UTC Considerationsfor more information concerning this topic.

Backup is provided if either the GTS or Stagelink Time Master becomes inoperative. If the GTS becomes inoperative, thebc620AT goes to flywheel mode with a drift of 2 ms per hour. In most cases, this allows sufficient time to repair the GTS

without severe disruption of the plant's system time.

If the primary Stagelink Time Master becomes inoperative, then each of the time slaves picks another, but the same,

secondary Stagelink Time Master. This means that all nodes on the Stagelink lock onto the identical reference for their

own time, even if the primary and secondary Stagelink Time Masters had different time bases for their reference.

Mark V selects the best Stagelink Time Master if multiple / Stagelinks exist and Stagelink Time Masters exist on

each network. This means that if two 's on the same stagelink are available Stagelink Time Masters and one of them

has lost contact with the GTS time signals, each time slave selects the other available Stagelink Time Master as its time

reference of choice.

If multiple available Stagelink Time Masters exist, each time slave selects the current Time Master based on the following:

whether or not the time master is tracking the GTS, and which time master has the lowest Stagelink (ARCNET) address.

2-3. SUPPORTED GTSs

The bc620AT board supports the use of several different time sources. However, the Time Synchronization software does

not support all sources supported by the bc620AT board.

The following is a list of time sources, and their characteristics, that are supported by both the bc620AT and the Time

Synchronization software:


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Chapter 2, Time Synchronization Theory6

Modulated IRIG-A, IRIG-B, 2137, or NASA-36 timecode signals

Modulation ratio 3:1 to 6:1

Amplitude 0.5 to 5 volts peak to peak

DC Level Shifted IRIG-A, IRIG-B, or NASA-36 timecode signals

TTL / CMOS compatible voltage levels

1PPS (one pulse per second) using theExternal 1PPSinput signal of the bc620AT board

TTL / CMOS compatible voltage levels, positive edge on time

1PPM (one pulse per minute) using theEvent Captureinput signal of the bc620AT board

TTL / CMOS compatible voltage levels, positive edgeon time

20 nanosecond minimum pulse width, 250 nanosecond minimum period

1PPH (one pulse per hour) using theEvent Captureinput signal of the bc620AT board

TTL / CMOS compatible voltage levels, positive edge on time

20 nanosecond minimum pulse width, 250 nanosecond minimum period

No Signal using the low-drift clock on the bc620AT board inFLYWHEELmode as the sole time source for the plant

There are two time sources supported by the bc620AT board but not supported by the Time Synchronization software.

These signals are XR3 timecodes and Negative Edge on time inputs.

NOTE

Nomenclature for IRIG timecodes is defined in Appendix B.


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Chapter 3, Hardware Setup 7

CHAPTER 3

HARDWARE SETUP

3-1. INTRODUCTION

To set up the Time Synchronization hardware, the bc620AT board must be correctly installed in the or and then

configured for this application. The setup of the Bancomm bc620AT board for the Mark V Time Synchronization option,

involves setting hardware jumpers to select the base I/O address of the board (see section 3-3), and disabling the IRQ

(Interrupt Request) since the software makes no use of interrupts for this board (see section 3-4). Then the GTS and the

's or 's must be connected (sections 3-5 and 3-6).

Figure 3-1 shows the general layout of the bc620AT board

JP1

SW1

J1

J2

BANCOMM bc620AT

I/O ADDRESS

IRQ JUMPERS

Figure 3-1. bc620AT Time and Frequency Module

3-2. BOARD INSTALLATION

The bc620AT board can be placed in any spare ISA (Industry Standard Architecture) slot of an or . See the PC

vendor user manual that comes with the or for proper installation procedures.

3-3. SETTING BASE I/O ADDRESS

The bc620AT board is shipped from the Bancomm factory with a base I/O address of 0x0300.This address conflicts with

the base I/O address used in 's with Ethernet boards and 's with the Historian option(see GEH-6123C, The

Mark V Historian Maintenance Guide and Users Manual). Therefore, always set the base I/O address to 0x0280 as shown

in Figure 3-2.


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Chapter 3, Hardware Setup8

1 2 3 4 5 6

OPEN

ON

OFF

SW1

A9 A8 A7 A6 A5 A0A1A2A3A4

1 0 1 0 0 0 000 0 = 0x0280

ONOFF

= 0= 1

INDICATES DIRECTION OF TOGGLE

Figure 3-2. SW1 Base I/O Address switch selections

3-4. SETTING THE IRQ

Adjust the board's IRQ setting toNo IRQas shown in Figure 3-3.

1 3 5 7 911

13

15

17

19

21

23Pin

IRQ IR15

IR14

IR12

IR11

IR10

IR9

IR7

IR6

IR4

IR5

IR3

NO

IRQ

JP1

Figure 3-3. IRQ selection on bc620AT

3-5. CONNECTING THE GTS TO THE BOARD

The bc620AT has two panel connectors, J1 and J2 (see Figure 3-1). J2 is not used for Mark V Time Synchronization. J1 is

a 15-pin receptacle D-connector and is used to connect the GTS. The type of GTS determines how J1 is interfaced. For most

GTSs, a 15-pin to BNC adapter is used. This connector consists of a 15-pin plug D-connector, and five BNC receptacle

connectors. Figure 3-4 shows a diagram of this adapter.


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Chapter 3, Hardware Setup 9

1 PPS Output

1 PPS Input

Timecode Output

Event Input

Timecode Input(Modulated)

Rece tacle

BNC's GTS Source

(Flywheel Mode Out)

(1 PPS)

(Optional External Use)

(1 PPM or 1 PPH)

(IRIG-A, IRIG-B,NASA36, or 2137)

Ada ter

15- in

D Plu

To

bc620AT

J1

Figure 3-4. 15-Pin D to BNC Adapter.

For dc Level Shifted timecode inputs, an adapter is required for J1 pin 12 (Ground) and pin 10 (DCLS Timecode Input) to a

BNC receptacle connector.

3-6. CONNECTING THE 's OR 's

All available Stagelink Time Masters are wired as a bus configuration using RG-58 coaxial cable and T-connectors (see

Figure 1-1). Since the timecode signals are low frequency signals (1 kHz for IRIG-B), special terminating resistors are not

required. This is in contrast to the 50 ohm resistors required for Ethernet (10 MHz) or the 93 ohm resistors required for

Stagelink (2.5 MHz).

Use the same lightning protection techniques for the timelink as for Stagelink or Ethernet. See the

documentation for these networks for protection techniques to be used.

The timelink cabling (RG-58) is identical to that used for Ethernet and very similar to that used forStagelink (RG-62). Label all cables used for timelink differently than the other network cables.

Damage to equipment is possible if these cables are interconnected.

CAUTION

CAUTION


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Chapter 3, Hardware Setup10

Notes:


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Chapter 4, Software Setup 11

CHAPTER 4

SOFTWARE SETUP

4-1. INTRODUCTION

The Timesync software must be configured correctly in order to communicate over the Stagelink. Data files must be

modified to define the Stagelink Time Master and specify the time base.

4-2. TIMESYNC DATAFILE

The Stagelink driver program in the 's and 's sends time to the Mark V control panels. This program uses the file

F:\TIMESYNC.DAT to get information regarding timesync/timeset information. The key lines in F:\TIMESYNC.DAT are

shown in Figure 4-1.

TIMESYNC BC620AT MODE [LEVEL_SHIFT] BASE_PORTxxxx I_TIMESET [ENABLED | DISABLED] I_TIME [LOCAL | UTC] PANEL_TIME [LOCAL | UTC] TIME_SOURCE [LOCAL | UTC] TIME_LOAD [MANUAL| LOCAL | NETWORK] TIME_OFFSET dd-mmm-yyyy hh:mm:ss.cc mmmm

Figure 4-1. Timesync Configuration Lines in F:\TIMESYNC.DAT

4-3. FILE CONFIGURATIONA template file for timesync is in G:\DATA\TIMESYNC.DAT. Copy this template file to F:\TIMESYNC.DAT and edit as

required. Figure 4-2 is an example of the template file TIMESYNC.DAT.

The file's key words and their significance are listed below:

TIMESYNC BC620AT

If the "TIMESYNC" line is missing, the will not have Stagelink Time Master functions. However, the other lines

may be specified such that the is a time slave.

BC620AT is the name of the Time/Frequency Processor board.

MODE

defines the type of global time source, and is one of the following:

IRIG-B Modulated IRIG-B Time Code Signal

IRIG-A Modulated IRIG-A Time Code Signal

NASA-36 Modulated NASA-36 Time Code Signal

2137 Modulated 2137 Time Code Signal

1PPS One pulse per second time input

1PPM One pulse per minute time input

1PPH One pulse per hour time input

FLYWHEEL Use the bc620AT board itself as the GTS


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Chapter 4, Software Setup12

; TIMESYNC Parameters. 11-JUL-1995;; The line beginning with "TIMESYNC" indicates time acquisition hardware; exists in the system. The only card supported thus far is the bc620AT; Time/Frequency board. The syntax of this line is:; TIMESYNC BASE_PORT MODE [LEVEL_SHIFT]; where is: BC620AT; is the base port address of the card inhex.; is one of the following:; IRIG-A IRIG-A Timecode.; IRIG-B IRIG-B Timecode.; NASA-36 NASA-36 bit timecode.; 2137 2137 Timecode.

; 1PPS 1 pulse per second.; 1PPM 1 pulse per minute.; 1PPH 1 pulse per hour.; FLYWHEEL Free Running Clock.

; "DC_SHIFT" is specified if the timecode is DC Level Shiftedrather; than modulated.TIMESYNC BC620AT BASE_PORT 280 MODE IRIG-B;; "I_TIMESET [ENABLED | DISABLED]" is used to allow the 's time to; be set to the same time as the Stagelink Time Master. Note the does; not require a time/frequency board in order to be a time slave.I_TIMESET ENABLED;; "I_TIME", "PANEL_TIME" and "TIME_SOURCE" identify what timebase isused; in , the Mark V, and the Global Time Source. Choices are UTC and

LOCAL.I_TIME LOCALPANEL_TIME LOCALTIME_SOURCE UTC;; "TIME_LOAD [MANUAL | LOCAL | NETWORK]" defines whether major timeelements; (year, day-of-year etc.) are derived from the PC automatically (i.e.LOCAL);; or obtained from other Stagelink Time Masters (i.e. NETWORK),; or whether TIMESYNC functions are disabled until major time isentered; manually via TIMEUTIL (i.e. MANUAL).TIME_LOAD LOCAL;; Time Offset Definition Table. Each entry defines number of minutes; correction to use when Global Time Source Time hits:; GLOBAL TIME SOURCE; ----------UTC---------- Minutes Correction to LOCALTimeTIME_OFFSET 25-OCT-1992 06:00:00.00 -300TIME_OFFSET 04-APR-1993 07:00:00.00 -240TIME_OFFSET 31-OCT-1993 06:00:00.00 -300TIME_OFFSET 03-APR-1994 07:00:00.00 -240TIME_OFFSET 30-OCT-1994 06:00:00.00 -300TIME_OFFSET 02-APR-1995 07:00:00.00 -240TIME_OFFSET 29-OCT-1995 06:00:00.00 -300


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TIME_OFFSET 07-APR-1996 07:00:00.00 -240TIME_OFFSET 27-OCT-1996 06:00:00.00 -300

Figure 4-2. Sample F:\TIMESYNC.DAT

LEVEL_SHIFT

"LEVEL_SHIFT" is used if IRIG-x, NASA-36, or 2137 timecodes are dc Level Shifted instead of modulated signals.


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Chapter 4, Software Setup14

BASE_PORT xxxx

"xxxx" is the HEX Base I/O address of the Time/Frequency Processor board; this parameter is normally 0280.

I_TIMESET [ENABLED | DISABLED]

This line defines whether the or time is set to the time defined by the stagelink time master (ENABLED), orfollows the CMOS clock (DISABLED).

I_TIME [LOCAL | UTC]

"I_TIME" is only applicable if the line "I_TIMESET ENABLED" line (above) exists in the data file. This customer

specified parameter defines whether the 's internal time is set to UTC or Local Time.

PANEL_TIME [LOCAL | UTC]

This customer specified parameter defines whether the Mark V panel time is UTC based or Local Time based.

TIME_SOURCE [LOCAL | UTC]

This line specifies whether the GTS is UTC based or Local Time based. This parameter applies only to timecode

GTSs; it does not apply to pulse input time sources.

TIME_LOAD [MANUAL | LOCAL | NETWORK]

This line enables or disables the automatic loading of initial major time fields. No Stagelink Timemaster will send

time until all major time elements are loaded, and time is locked to the GTS.

" MANUAL" disables the as a Stagelink time master until major time elements are manually entered. See section

describing the TIMEUTILprogram for more details.

"LOCAL" specifies that major time is loaded automatically from the 's CMOS clock.

"NETWORK" specifies that major time is loaded from another Stagelink Timemaster, assuming multiple 's on the

Stagelink have Time/Frequency processor boards installed.

For IRIG-A, IRIG-B and NASA-36 timecodes, major time elements consist only of the year (since these are time-of-

year timecodes). For 2137 timecode, major time consists of current year, month and day, as this is a time-of-day

timecode. For pulse input styles of GTS, major time consists of current year, month, day, hour, minute, and seconds.

NOTE

"TIME_LOAD LOCAL" is not recommended for 1PPS Global Time Sources, since the CMOS

clock may have errors in time on the order of several seconds.

TIME_OFFSET dd-mmm-yyyy hh:mm:ss.cc mmmm

"TIME_OFFSET" lines can be specified more than once. For normal operation, where the global timecode source is

UTC, these lines define the correction applied to the global time source in order to display timetagged data in local

time. In this case, "dd-mmm-yyyy hh:mm:ss.cc" defines the UTC Time at which "mmmm" minutes of correction takes

place.

Example: Enter Eastern Daylight Time on April 3, 1994.

TIME_OFFSET 03-APR-1994 07:00:00.00 -240


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This example says that beginning on 3-APR-1994 at 07:00 AM UTC, the local correction added to UTC to arrive at EDT

(Eastern Daylight Time) is -240 minutes. (Eastern Standard Time correction would be -300 minutes.)

NOTE

All 's or 's in a system must be setup in F:\TIMESYNC.DAT in an identical fashion, with the

exception of those computers not having a bc620AT card installed. Failure to have identical systemsetup can cause shifts in the Stagelink Time Reference upon power down of the primary Stagelink

Time Master.

NOTE

's or 's not containing a bc620AT time/frequency processor card should have the identical

lines in F:\TIMESYNC.DAT, but with the "TIMESYNC..." line commented out.


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Chapter 5, Local Time vs. UTC Considerations16

CHAPTER 5

LOCAL TIME vs. UTC CONSIDERATIONS

5-1. INTRODUCTION

This chapter defines the use of F:\TIMESYNC.DAT and F:\GSM_SERV.DAT and how each of these configuration files

interact relative to the time sources. Mark V panel system time, / local time, the CMOS clock, and the GTS time

references are discussed in this chapter, as well as UTC and Local GTSs.

5-2. INTERNAL TIME REFERENCES

An or computer has three time references independent of a global time. These are:

The CMOS clock, used by BIOS

The DOS software clock IDOS operating system time

Each time reference can be different from the others.

The Mark V system clock is usually close to, but not necessarily the same as, the or time references.

There are many base time references, but usually two are involved: UTC and Local Time. UTC has an appeal for historical

applications in that it never steps backward nor jumps forward. Therefore, historical data stored using UTC uniquely

identifies when the data was generated. Local Time has an appeal for real-time data displays, but tends to jump forward

and backward, causing discontinuities when used in historical data.

Mark V time synchronization is designed to handle both historical and real-time data display.

Current Mark Vs typically use Local Time as the time base.

5-3. GTS is UTC (non-changing standard time)

The computer uses GSM (GE Drive Systems Standard Messages). GSM transmits time-tagged data using UTC as the

time base. The computer uses F:\GSM_SERV.DAT to define the correction factors to Local Time ( Mark V panel

time). This allows the time tags that it supplies with transmitted data to properly represent UTC.

If the GTS is UTC based, and Mark V time is specified to use UTC, then F:\GSM_SERV.DAT does not need to exist.

Therefore, the correction to Mark V time is zero in this case. If the Mark V time is specified to use LOCAL, then

F:\GSM_SERV.DAT must exist to provide these time corrections.

UTC time reference is recommended for the GTS so that automatic Local Time corrections can be made by the Stagelink

Time Master at the instant Daylight Savings Time changes. This is independent of whether Mark V internal time is UTC

or LOCAL based.

The time base used in 's or 's can be set to either UTC or Local. Local is preferred for timestamping file dates, but

is not required. The real-time and historical plot programs must know which time base is used in the versus the Mark

V data to provide correct timescales for their plots.

NOTE


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Chapter 5, Local Time vs. UTC Considerations 17

Both and Mark V times must currently use the same time base for the plotting programs to execute

properly.

5-4. GTS is LOCAL (Changes twice per year)

As mentioned above, the computer uses F:\GSM_SERV.DAT to correct Mark V panel time to UTC for transmitted

timetagged data. If the GTS is LOCAL, and Mark V panel time is specified as LOCAL, then F:\GSM_SERV.DAT must

contain entries defining corrections to LOCAL time to arrive at UTC.

The potential problem of using a GTS with LOCAL time is that changes of the GTS to and from Daylight Savings Time

may not exactly coincide with the expected changes defined in F:\GSM_SERV.DAT. The same potential problem exists in

F:\TIMESYNC.DAT if Mark V panel time is specified to be UTC. However, F:\GSM_SERV.DAT is not needed in this

case.


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Chapter 6, Timesync Operations18

CHAPTER 6

TIMESYNC OPERATION

6-1. INTRODUCTION

This chapter covers normal timesync/timeset operations, as well as use of the TIMEUTILprogram.

6-2. GENERAL OPERATIONS

Upon bootup, no acts as an available Stagelink Timemaster until the following conditions are met:

1. Major time elements (year, month, day etc.) have been acquired from CMOS memory, another Stagelink Time Master,

or manually through the TIMETUTILprogram.

2. The GTS has established its presence and the bc620AT board has asserted its trackingstatus bit. (This is ignored ifmodeis set to FLYWHEEL.) For pulse input GTS, at least one reference pulse must have been recorded after major

time was loaded.

NOTE

Item number one above does not occur automatically upon or bootup if the line

"TIMELOAD MANUAL" is specified in F:\TIMESYNC.DAT. Use of theTIMEUTIL program is

required to load major time elements in this case.

Every 20 seconds, each available Stagelink Time Master broadcasts an identification message announcing its availability.

Every 32 seconds, each Mark V panel asks the selected Stagelink Time Master for the current date/time. It jumps or slews

its internal time based on the time error calculated. The rate of slew allows for sub-millisecond errors, assuming the GTS is

stable.

Every 60 seconds, all nodes select the Stagelink Time Master of choice (if more than one is available) based on Stagelink

address, timesync accuracy, and tracking status (as stated in chapter 2, Time Synchronization Theory).

Every 20 minutes, each or with the "I_TIMESET ENABLED" line in F:\TIMESYNC.DAT performs a TIMESET

function, by asking the selected Stagelink Time Master for the current date/time. Unlike the timesync function in Mark V,

the timeset function in or does not slew its internal time, it jumps. The time error in this timeset function is

typically 27 ms, assuming the GTS is stable.

Each available Stagelink Time Master does a limited amount of stability checking on the Global Time Source (timecode

GTSs only). If the time-of-year ever changes by more than 30 seconds (except changing from December 31, 23:59:59 toJanuary 1, 00:00:00), the timesync function is disabled for a minimum of three minutes. If the time-of-year continuously

increases at a normal rate for more than three consecutive minutes, the timesync function automatically resumes.


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Chapter 6, Timesync Operations 19

6-3. USING THE TIMEUTIL PROGRAM

The TIMEUTILprogram controls time synchronization in the or functioning as the Stagelink Time Master. This

program is used to do the following:

Obtain status about the Stagelink Time Master, and other available time masters on the Stagelink

Enable or Disable the timesync functions Set the MAJOR TIME in the Stagelink Time Master

TIMEUTILis a maintenance program and is only accessible from the DOS prompt. If run without parameters, TIMEUTIL

gives limited help on its usage. Listed below are a few operations in TIMEUTIL.

6-3.1. Turning the TIMESYNC Function Off

To turn off the timesync function in an available Stagelink Time Master, enter:

C:\> TIMEUTIL TIMESYNC DISABLE

6-3.2. Turning the TIMESYNC Function Back On

To restore the timesync function in an available Stagelink Time Master, enter:

C:\> TIMEUTIL TIMESYNC ENABLE

6-3.3. Loading MAJOR TIME into the bc620AT Board

Depending on the type of GTS, and TIME_LOAD option specified in F:\TIMESYNC.DAT, the may not act as an

available Stagelink Time Master until major time has been loaded and the bc620AT board has locked on to the GTS. (This

means it is "tracking" the GTS.)

To load major time into the bc620AT board, enter:

C:\> TIMEUTIL TIMELOAD dd-mmm-yyyy hh:mm:ss.cccc

and press as close as possible to the entered time (down to the second).

If the overall timesync function has not been turned off, the automatically assumes Stagelink Time Master duties as

follows:

After the next pulse input if the GTS is a pulse

After the next timecode frame if the GTS is a timecode Immediately if the timesync mode is set to FLYWHEEL.

If "dd-mmm-yyyy hh:mm:ss.cccc" is left off the command line, TIMEUTILprompts for this.


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Chapter 7, Diagnostics and Troubleshooting20

CHAPTER 7

DIAGNOSTICS AND TROUBLESHOOTING

7-1. INTRODUCTION

This chapter covers some of Mark V Time Synchronizations built-in diagnostics and troubleshooting features. TIMEUTIL

and the trace buffers are discussed here.

7-2. Obtaining General Information About the Mark V Timesync Function

The information available about Mark V Timesync is formatted such that it may exceed 25 lines of output. For this reason,

set the screen to 50 line mode by entering C:\> V50, or redirect the output to a file.

To obtain timesync status information, enter:

C:\> TIMEUTIL STATUS

or

C:\> TIMEUTIL STATUS >filename.out

The information returned by TIMEUTIL STATUS varies slightly depending on whether the GTS is a timecode signal, or

pulse input.

Figure 7-1 shows a sample output from TIMEUTIL STATUS for an IRIG-B GTS. This example was done on November 4,

1994, the 308th

day of the year.


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Chapter 7, Diagnostics and Troubleshooting 21

TIMESYNC STATUS

Overall TIMESYNC Function: ENABLED

TIMESYNC Controller: bc620AT I/O Base Address: 0280 IRQ: None

TIMESYNC Mode: IRIG-B (Modulated) Status: TRACKING

Global Time Acquired: YES Year: 1994 Days: 308

Pulse Correction in Use: N/A

Major Time Load Flag: LOCAL CMOS

Global Time Source: UTCMark V Panel Time: LOCAL/ CPU Time: LOCAL / Timeset: ENABLED

Number of Stage Link Time Masters: 3

# Address Status Selected01 0x1F 0x0103 x02 0x20 0x010303 0x22 0x0103

Local ARCNET address: 0x1F

Figure 7-1. Sample output from TIMEUTIL STATUS

Items to Note in the Information Shown Above

The GTS is IRIG-B, and current status is TRACKING(the GTS is present). Otherwise, current status would beFLYWHEELING rather thanTRACKING.

IfGlobal Time AcquiredwasNO, then this is not going to attempt to pass time to other nodes on the Stagelink. NOimplies that the IRIG-B timecode signal has never been detected by the bc620AT board; or if the GTS is a pulse input, thatno pulses have been received.

If Yearis 0, then major time elements have not been loaded; this is not going to attempt to send time to other nodes onthe Stagelink. The same is true ifDays(the current day-of-year) is 0.

If the GTS is a pulse input (1PPM or 1PPH), the current pulse correction in use is displayed. This is less than or equal to

30 seconds for 1PPM, or 30 minutes for 1PPH. It showsN/Afor timecode GTSs, 1PPS, or FLYWHEEL modes. Thebc620AT board tracks 1PPS inputs directly.

The next five lines reflect information in F:\TIMESYNC.DAT.

At the bottom of the display is a list of all available Stagelink Time Masters (on this 's Stagelink), their address, theirstatus, and which is the selected Stagelink Timemaster used by all nodes on this Stagelink.

NOTE

In a normal, functioning system, all statusdigits displayed for each available Stagelink Timemastershould be identical. If not, then verify that F:\TIMESYNC.DAT in each or has the sameinformation for the following parameters:

TIME_SOURCE [LOCAL | UTC]PANEL_TIME [LOCAL | UTC]I_TIME [LOCAL | UTC]


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The status is displayed in hexadecimal. The current definition for each bit is shown below. Bit 0 is considered the leastsignificant (rightmost) bit.

Bit 0: 1 ==> Stagelink Timemaster is tracking the GTS.0 ==> Stagelink Timemaster is flywheeling.

Bit 1: Reserved. Normally has a value of 1.

Bits 2-7 Reserved. Normally has a value of 0.

Bit 8: 1 ==> GTS is UTC based.0 ==> GTS is LOCAL.

Bit 9: 1 ==> /'s time is UTC based.0 ==> /'s time is LOCAL.

Bit 10: 1 ==> Mark V's time is UTC based.0 ==> Mark V's time is LOCAL.

Bits 11-15: Reserved. Normally has a value of 0.

Reserved bit definitions are subject to change.

7-3. OTHER TIMESYNC DIAGNOSTIC CAPABILITIES

Each or with a bc620AT board installed, maintains a trace buffer in extended memory. This trace buffer contains

encoded recordings of the last 8192 timesync protocol messages transmitted or received from the Stagelink. The

information in these trace buffers can show the current time error in each time slave.

Decoding the trace buffer requires two steps:

1. Get a copy of the trace buffer into a binary file by entering at the DOS prompt:

C:\> GBL2FILE timesync_trace TIMESYNC.BIN

The timesync_traceparameter must be in lowercase letters.

2. Format the binary file into an ASCII text file by entering:

C:\> TS_DUMP TIMESYNC.BIN TIMESYNC.OUT

Now this information is in the file TIMESYNC.OUT. The timesync protocol traces forMessage Type: 4 (Time Diagnostic).

These time diagnostic messages contain error corrections between the Stagelink Time Master and the time slave. Other

message type dumps are used for development purposes only, and are not discussed here. A portion of a sample output from

TS_DUMP is shown in Figure 7-2 below:


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Chapter 7, Diagnostics and Troubleshooting 23

00000001, 00 --> 00 (OUT) Msg. Type: 1 (Timesync Master ID)Sequence #0001 Highest Time Format: 4, Timesync Master Status: 0103 Packet recorded at: 04-NOV-1994 14:46:00.9474 (IDOSTime)

00000002, F5 --> 1F (IN) Msg. Type: 2 (Request For Time)

Sequence #0002 Time Format: 2, bc620AT Time: 308 19:46:09.497153 Packet recorded at: 04-NOV-1994 14:46:00.9474 (IDOSTime)

00000003, F5 --> F5 (OUT) Msg. Type: 3 (Time Response)Sequence #0002 Time Format: 2, Local Correction: 0000, ResponseStatus: 0000 Time Returned: 04-NOV-1994 14:46:09.4972 Packet recorded at: 04-NOV-1994 14:46:00.9474 (IDOSTime)

00000004, F4 --> 1F (IN) Msg. Type: 2 (Request For Time)Sequence #0002 Time Format: 2, bc620AT Time: 308 19:46:09.498055 Packet recorded at: 04-NOV-1994 14:46:00.9474 (IDOSTime)

00000005, F4 --> F4 (OUT) Msg. Type: 3 (Time Response)Sequence #0002 Time Format: 2, Local Correction: 0000, ResponseStatus: 0000 Time Returned: 04-NOV-1994 14:46:09.4980 Packet recorded at: 04-NOV-1994 14:46:00.9474 (IDOSTime)

00000006, F5 --> 1F (IN) Msg. Type: 4 (Time Diagnostic)Sequence #0002 Time Format: 2, Delta-Time: -0000 00:00:21.0427 Packet recorded at: 04-NOV-1994 14:46:00.9474 (IDOSTime)

00000007, F4 --> 1F (IN) Msg. Type: 4 (Time Diagnostic)Sequence #0002 Time Format: 2, Delta-Time: +5420 14:18:07.0465 Packet recorded at: 04-NOV-1994 14:46:00.9474 (IDOSTime)

. .00000012, F5 --> 1F (IN) Msg. Type: 4 (Time Diagnostic)Sequence #0004 Time Format: 2, Delta-Time: -0000 00:00:00.0140 Packet recorded at: 04-NOV-1994 14:46:50.6921 (IDOSTime)

00000013, F4 --> 1F (IN) Msg. Type: 2 (Request For Time)Sequence #0004 Time Format: 2, bc620AT Time: 308 19:46:52.332006 Packet recorded at: 04-NOV-1994 14:46:52.2849 (IDOS

Time)

00000014, F4 --> F4 (OUT) Msg. Type: 3 (Time Response)Sequence #0004 Time Format: 2, Local Correction: 0000, ResponseStatus: 0000 Time Returned: 04-NOV-1994 14:46:52.3320 Packet recorded at: 04-NOV-1994 14:46:52.2849 (IDOS

Time)

00000015, F4 --> 1F (IN) Msg. Type: 4 (Time Diagnostic)Sequence #0004 Time Format: 2, Delta-Time: +0000 00:00:00.0282 Packet recorded at: 04-NOV-1994 14:46:52.2849 (IDOSTime) . .0000049E, F4 --> F4 (OUT) Msg. Type: 3 (Time Response)Sequence #009D Time Format: 2, Local Correction: 0000, ResponseStatus: 0000 Time Returned: 04-NOV-1994 16:08:25.9963 Packet recorded at: 04-NOV-1994 16:08:25.9646 (IDOSTime)


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0000049F, F4 --> 1F (IN) Msg. Type: 4 (Time Diagnostic)Sequence #009D Time Format: 2, Delta-Time: -0000 00:00:00.0002 Packet recorded at: 04-NOV-1994 16:08:25.9646 (IDOSTime)

Figure 7-2. Sample output from TS_DUMP


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Chapter 8, Example Timesync Configurations 25

CHAPTER 8

EXAMPLE TIMESYNC CONFIGURATIONS

8-1. EXAMPLE 1 USING A SINGLE AS THE GLOBAL TIME SOURCE

This example uses a single as the GTS for the entire plant, using the low-drift capabilities of the bc620AT board.

Figure 8-1 shows a typical layout. Follow the steps below for setup.

1. If multiple 's exist, install the bc620AT board into the containing the lowest Stagelink address. This is

referred to as the PRIMARY in this example.

2. If redundant bc620 boards exist, install the board(s) in the ('s) with higher Stagelink addresses than the PRIMARY

described in step 1. These 's are referred to as SECONDARY 's in this example.

3. Connect RG-58 cable from the TIMECODE OUTPUTBNC connector of the PRIMARY to the TIMECODE INPUT

BNC connectors on each SECONDARY . Use T-connectors to parallel the signal from computer to computer. Inaddition, parallel this cable to any DCS equipment which are to act as time slaves to the PRIMARY .

4. Optionally, the 1PPSoutput can be connected to DCS equipment that are to act as time slaves to the PRIMARY .

5. Configure F:\TIMESYNC.DAT in the PRIMARY with the following:

TIMESYNC BC620AT MODE FLYWHEEL BASE_PORT 0280

TIME_SOURCE LOCAL

PANEL_TIME LOCAL

I_TIME LOCAL

TIME_LOAD LOCAL

I_TIMESET ENABLED

6. Configure F:\TIMESYNC.DAT in each of the SECONDARY 's with the following:

TIMESYNC BC620AT MODE IRIG-B BASE_PORT 0280

TIME_SOURCE LOCAL

PANEL_TIME LOCAL

I_TIME LOCAL

TIME_LOAD LOCAL

I_TIMESET ENABLED

7. If TIMESET capability is wanted in any or without a bc620AT board installed, configure

F:\TIMESYNC.DAT in those computers with I_TIMESET ENABLED. (Other parameters are not required.)


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Chapter 8, Example Timesync Configurations26

MK V

1#

MK V#2

MK V#3

STAGELINK (ARCNET)

(RG-62 COAX CABLE)

PRIMARY

TIMECODE

OUT BNC

SECONDARY

SECONDARY

IRIG-B TIMECODETO DCS EQUIPMENT

RG-58

COAX

CABLE

1PPS

OUT BNC

TIMECODE

IN BNC

TIMECODE

IN BNC

*

*

*

* Optional

1 PPS

TO

DCS EQUIPMENT*

TERMINATIONRESISTOR

TERMINATIONRESISTOR

Figure 8-1. - Typical Layout for FLYWHEELING Timesync Mode

8-2. EXAMPLE 2 USING IRIG-B TIMECODE AS THE GTS WITH MULTIPLE STAGELINK

TIMEMASTERS AND MULTIPLE / STAGELINKS

This example uses a single box as the GTS for the entire plant, possibly a satellite receiver, that generates an IRIG-B

timecode signal. Figure 8-2 shows a typical layout. Follow the steps below for setup.

NOTEFor redundancy requirements, no more than two computers per Stagelink need to have

bc620AT boards installed.

1. Install a bc620AT board in each or to be used as an available Stagelink Time Master.

2. Connect RG-58 cable from the source of the IRIG-B timecode signal to each bc620AT board, using the TIMECODE

INPUTBNC connector. Use T-connectors to parallel the signal to each board.

3. Continue the RG-58 cabling to any other piece of equipment in the plant that is to act as a time slave.


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4. Configure F:\TIMESYNC.DAT in each of the 's or 's that have bc620AT boards installed as follows:

TIMESYNC BC620AT MODE IRIG-B BASE_PORT 0280

TIME_SOURCE LOCAL

PANEL_TIME LOCAL

I_TIME LOCAL

TIME_LOAD LOCAL I_TIMESET ENABLED

NOTE

If the timebase of the IRIG-B timecode signal is UTC, change the "TIME_SOURCE LOCAL"

line above to "TIME_SOURCE UTC".

5. If TIMESET capability is wanted in any or without a bc620 AT board installed, configure


MK V

# 1

MK V

# 2

MK V

# 3

STAGELINK (ARCNET)(RG-62 COAX CABLE)

TIMECODE

IN BNC

IRIG-B TIMECODE

TO OTHER PLANT

RG-58

COAX

CABLE

TIMECODE

IN BNC

TERMINATIONRESISTOR

# 1

# 2

# 3

# 4

IN BNC

TIMECODE

IN BNC

TIMECODE

EQUIPMENT

IRIG-B TIMECODE

SIGNAL FROM SATELLITE

RECEIVER OR

OTHER DEVICE

STAGELINK (ARCNET)

(RG-62 COAX CABLE)

TERMINATION

RESISTOR

TERMINATION

RESISTOR

TERMINATION

RESISTOR

Figure 8-2. - Typical Layout for External IRIG-B GTS, using redundancy and multiple Stagelink Networks


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8-3. EXAMPLE 3 USING PULSE INPUTS AS THE GTS WITH MULTIPLE STAGELINK

TIMEMASTERS AND MULTIPLE / STAGELINKS

This example uses a single box as the GTS for the entire plant, possibly a satellite receiver, that generates one pulse per

minute (or hour) as a time reference. Figure 8-3 shows a typical layout. Follow the steps below for setup.

NOTE

For redundancy requirements, no more than two computers per Stagelink need to have

bc620AT boards installed.

1. Install a bc620AT board in each or to be used as an available Stagelink Time Master.

2. Connect RG-58 cable from the source of the pulse input signals to each bc620AT board, using theEVENT INPUT

BNC connector. Use T-connectors to parallel the signal to each board.

3. Continue the RG-58 cabling to any other piece of equipment in the plant that is to act as a time slave.

4. Configure F:\TIMESYNC.DAT in each of the 's or 's that have bc620AT boards installed as follows:

TIMESYNC BC620AT MODE 1PPM BASE_PORT 0280

TIME_SOURCE LOCAL

PANEL_TIME LOCAL

I_TIME LOCAL

TIME_LOAD LOCAL

I_TIMESET ENABLED

NOTE

If the pulse rate is 1 pulse per hour, change 1PPM above to 1PPH.

5. If TIMESET capability is wanted in any or without a bc620 AT board installed, configure


Notes for interfacing pulse input references:

The bc620AT has internal 4.7 kpullup resistors between a +5 V power source and both the 1PPS InputandEvent Input

signals. Therefore any interface to these inputs must be able to draw at least 1 mA of current per bc620AT board.

Pulse inputs are positive edge on time. The interface must be at logic 0except when the reference pulse is active. Pulse

input references must be stable, therefore only use stable pulse references. For example, 1 PPM references pulses should be

as close to 60.00000 seconds apart as possible. Otherwise, Mark V timesync loses accuracy.

The use of electro-mechanical relays for pulse inputs is not recommended. The use of open collector circuits or solid state

relays is acceptable. GE does not recommend using software operating systems in the DCS to generate the reference pulses.

Pulse input references are at logic0most of the time. Therefore, the bc620ATs BNC connector records a false pulse input

when the reference cable is disconnected from the bc620AT board. The board senses a positive edge caused by the internal

4.7 kpullup resistor. The card then sends invalid time to the Mark V panels until the next true reference pulse is

signaled. GE recommends restarting the or software after the reference cables are reconnected.


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MK V# 1

MK V

# 2

MK V

# 3

STAGELINK

(RG-62 COAX CABLE)

BNC

PULSE CODESTO OTHER PLANT

RG-58

COAX

CABLE

TERMINATION

RESISTOR

# 1

# 2

# 3

# 4

EQUIPMENT

1 PULSE PER MINUTE

OR 1 PULSE PER HOUR

SATELLITE RECEIVER

OR OTHER DEVICE

STAGELINK (ARCNET)

(RG-62 COAX CABLE)

EVENT IN

EVENT IN

BNC

EVENT IN

BNC

EVENT IN

BNC

TERMINATION

RESISTOR

TERMINATION

RESISTOR

TERMINATIONRESISTOR

Figure 8-3. - Typical Layout for External 1PPM or 1PPH GTS, with Redundant Stagelink Time Masters and Multiple Stagelink

Networks


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Notes:


41/44


Appendix A, Glossary of Terms 31

APPENDIX A

GLOSSARY OF TERMS

NOTE

Some of these terms are taken from the Bancommbc620AT T ime and Fr equency Module, Operation

and Technical Manual.

NOTE

In the description of the various timecode signals below, resolutionof the timecode signal should not

be confused with available accuracy. Special circuitry on the bc620AT allows the TFP to phase-lock

to the timecodes, achieving much higher accuracythan the base resolutionof the timecode signal

itself.

2137 A 1 kHz modulated signal. Frame rate is 1 code per second. This is a time-of-day reference. Resolution: 1 ms.

ARCNET A LAN communications protocol developed by Datapoint Corporation, used to link exciters, drives, and

controllers. Allows a maximum of 255 drops with transmission at 25 Mbit/s.

BCD Binary Coded Decimal.

CF Control Functions.

Daylight Savings Time Time change observed in parts of the world to extend the number of daylight hours.

DCS Distributed Control Systems.

EDT Eastern Daylight Time. Reference to Daylight Savings Time in the Eastern United States.

EST Eastern Standard Time.

EPOCH A reference event. In timing applications, epoch often refers to a one pulse per second event.

FLYWHEEL In the timekeeping vernacular to 'flywheel' means to maintain time or frequency or both after the input

reference is removed or lost.

GSM Gateway computer interface for the Mark V Turbine Control System using Ethernet in place of the Stagelink.

See .

GPS Global Positioning Satellite. The fleet of GPS vehicles is used worldwide for navigational purposes by aircraft andships for position and velocity measurements. In addition, time-of-year information can be obtained by a GPS

receiver.

GPS Time Time reference available from GPS space vehicles which includes the accumulation of leap seconds. Leap

seconds are typically added or subtracted on June 30th

and December 31stof each year as needed to correct UTC.

GSM GE Drive Systems Standard Message.

GTS Global Time Source. This is the source of time reference used for synchronization of time for all Mark V's and DCS

subsystems.


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Appendix A, Glossary of Terms32

The Mark V Turbine Control Systems primary operator interface. Consists of a computer interface with GEs version

of ARCNET called the Stagelink.

I/O Input/output. Interfaces that allow the flow of data into and out of a device

IRIG Inter-Range Instrumentation Group. This group defines a family of timecode signals (both modulated and dc level

shifted) at various frequencies and frame rates. The IRIG timecodes are time-of-year references.

IRIG-A A 10 kHz modulated or dc level shifted signal. Frame rate is 10 codes per second. Resolution: 0.1 ms.

IRIG-B A 1 kHz modulated or dc level shifted signal. Frame rate is 1 code per second. Resolution: 1 ms.

IRIG-G A 100 kHz modulated or dc level shifted signal. Frame rate is 100 codes per second. Resolution: 0.01 ms.

IRQ Interrupt Request

Local Time A time reference commonly used in the geographic locale of the equipment. Local time is subject tojerks in

timecaused by jumping the time reference forward in the spring for Daylight Savings Time, and jumping backward

in the fall to return to Standard Time (in the Northern hemisphere).

MAJOR TIME Units of time equal to or larger than seconds. Years, days, hours, minutes, and seconds are usually

implied.

MINOR TIME Subsecond time to whatever resolution is supported.

NASA-36 A 1 kHz modulated or dc level shifted signal. Frame rate is 1 code per second. This is a time-of-year

reference. Resolution: 1 ms.

PPx Pulse Per x. A GTS using periodic pulses to mark an epoch as a time reference. Typical rates are 1 PPS (Pulse Per

Second), 1 PPM (Pulse Per Minute) or 1 PPH (Pulse Per Hour).

Receptacle A type of electrical fitting designed to connect with a plug, or prong, connector. Formerly referred to as

female.

SBS Straight Binary Seconds

Slave Device that follows commands from a remote master control device. Also referred to asfollower.

Stagelink GEs version of ARCNET used in Turbine applications. See ARCNET.

Timeset The act of setting a clock to a time reference. This action does not imply any particular accuracy.

Timesync The act of locking a clock to a time reference. This action implies a continuous operation used to minimize

loss of accuracy of the clock being synchronized referenced to the global time source.

UTC Universal Time Coordinated. This is the time reference used at the zero meridian. Also known as GMT

(Greenwich Mean Time).

XR3 A 250 Hz modulated signal. Frame rate is 1 code per second. This is a time-of-day reference. Resolution: 4 ms.


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Appendix B, IRIG Nomenclature 33

APPENDIX B

IRIG NOMENCLATURE

IRIG Time Codes have alphabetical as well as numerical designations. The nomenclature is defined as follows:

Rate Designation

A: 1000 pps

B: 100 pps

D: 1 ppm

E: 10 pps

G: 10000 pps

H: 1 pps

Form Designation

0: Pulse, width-coded

1: Sine wave, amplitude-modulated

Carrier/Resolution

0: No carrier/index count interval

1: 100 Hz/10 ms

2: 1000 Hz/1 ms

3: 10000 Hz/0.1 ms

4: 100000 Hz/0.01 ms

Coded Expressions

0: BCD, CF, SBS

1: BCD, CF

2: BCD

3: BCD, SBS

The following is a list of recognized standard IRIG codes:

* Format A: A000, A003, A130, A133

* Format B: B000, B003, B120, B123

Format D: D001, D002, D111, D112, D121, D122

Format E: E001, E002, E111, E112, E121, E122Format G: G001, G002, G141, G142

Format H: H001, H002, H111, H112, H121, H122

* Supported by Mark V Time Synchronization


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GE Motors &Industr ia lSystems

General Electric CompanyIndustrial Systems1501 Roanoke Blvd.Salem, VA 24153-6492 USA