UNION SWITCH & SIGNAL 6696 User Manual

UNION SWITCH & SIGNAL

645 Russell Street
Batesburg, SC 29006

Service Manual

R

7063

Digitair Model 6696

End-of-Train

Communication Display Unit

Installation

Operation

October 1996

July 1997

COPYRIGHT 1995, UNION SWITCH & S IG NA L



1997 Union Switch & Signal Inc.

PRINTED IN USA

Printed in USA

An Ansaldo Affilated Company

An ANSALDO Affiliated Company

TABLE OF CONTE NTS

SM 7063 07/97

ii

TABLE OF CONTE NTS

I INTRODUCTION............................................................................................................. 1-1

1.0 PURPOSE OF MANUAL................................................................................................. 1-1

1.1 GENERAL OVERVIEW................................................................................................... 1-1

1.1.1 CDU FUNCTIONAL DESCRIPTION .............................................................................. 1-2

1.2 DEFINITION of TERMS ................................................................................................. 1-2

1.3 PATENTS AND TRADEMARKS.....................................................................................1-3

1.4 R.A.I.L. TEAM AND TECHNICAL SUPPORT................................................................. 1-3

1.5 CDU ORDERING INFORMATION ................................................................................. 1-3

1.5.1 Mounting and Hardware Options ...................................................................................... 1-3

1.5. 2 Parts U se d fo r In s t a ll a ti o n ................................................................................................ 1-4

1.5.3 Diagnostic Software Disk ................................................................................................. 1-4

1.5. 4 CDU Execu t a b le S o ft ware Disk .......................................................................................1-4

1.6 CDU SPECIFICATIONS ................................................................................................. 1-5

1.7 CDU MAJOR COMPONENTS........................................................................................ 1-6

1.7.1 CDU Unit Housing ..........................................................................................................1-6

1.7.2 CDU Rear Panel ............................................................................................................. 1-7

1.7.3 CDU Major Assemblies .................................................................................................. 1-8

1.8 CDU FUNCTIONAL BLOCK DIAGRAM ........................................................................ 1-9

II INSTALLATION.............................................................................................................. 2-1

2.0 INSTALLATION OF THE CDU ....................................................................................... 2-1

2.1 General Description ......................................................................................................... 2-1

2.2 Preparing the Locomotive ................................................................................................ 2-1

2.2.1 Mounting Tray Installation ................................................................................................ 2-1

2.2.2 AAR Clean Cab Enclosure .............................................................................................. 2-2

2.3 Inst allin g t h e CDU Ca b le s ................................................................................................ 2-2

2.3. 1 Pow e r Ca b l e I n st a ll a t io n ..................................................................................................2-2

2.3. 2 Odome t e r (A xle Alte rn a t o r) C a b le I n s ta l la t io n .................................................................. 2-2

2.3.3 Antenna and Cable Installation ........................................................................................ 2-4

2.3.4 CDU Datalogger Connector ............................................................................................. 2-4

2.3.5 Event Recorder Connector .............................................................................................. 2-4

2.4 MOUNTI NG THE CDU .................................................................................................... 2-5

2.4. 1 72 VDC / 1 2 V D C P o wer Sele c t io n J u mp e r (J P 1 ) ............................................................ 2-5

2.4.2 Installing the CDU on to a Mounting Tray .......................................................................... 2-5

2.4.3 Installing the CDU int o a n AA R Clean Cab Enclosure ...................................................... 2-5

2.5 BRIEF O P E RA T IO NA L T ES T O F TH E CDU ................................................................... 2-6

2.5.1 CDU Power-Up S equence ............................................................................................... 2-6

2.5.2 CDU Functional Check .................................................................................................... 2-7

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TABLE OF CONTE NTS

III OPERATION ................................................................................................................. 3-1

3.0 CDU OPERATING INSTRUCTIONS ............................................................................. 3-1

3.1 Purpose and Use of ID Code ......................................................................................... 3-1

3.2 Radio Communication Channel ...................................................................................... 3-1

3.3 DESCRIPTION of CDU FRONT PANEL DISPLAYS and CONTROLS .........................3-2

3.4 DESCRIPTION of CDU DISPLAY SYSTEM .................................................................. 3-2

3.4.1 Brake Pressure Display .................................................................................................. 3-2

3.4.2 Message Receipt Indicator in Pressure Display .............................................................. 3-3

3.4.3 ID Code Display .............................................................................................................. 3-3

3.4.4 Function Menu Display ................................................................................................... 3-4

3.4.5 LED Annunciators ........................................................................................................... 3-5

3.4.6 ARMED Status LED (Optional) ...................................................................................... 3-6

3.5 FUNCTION K EYS .......................................................................................................... 3-7

3.6 EMERGENCY BRAKE SWITCH .................................................................................... 3-8

3.7 SONALERT ................................................................................................................. 3-8

3.8 OPERATION of CDU FUNCTION MENU ITEMS .......................................................... 3-9

3.8.1 Viewing and Changing the ID Code ............................................................................... 3-9

3.8.1.1 Operation if “Allow Changing Between One and Two Way ID Menu” is Enabled........... 3-9

3.8.1.2 Operation of Change ID Code Display if “Blank ID Menu During No Activity”

is Enabled ............................................................................................................... 3-11

3.8.2 Entering the Train Length ............................................................................................. 3-11

3.8.3 Measuring Distance Traveled Using the Odometer (Count Up from Zero) ................. 3-12

3.8.4 Using the Train Length Distance Function (Count Down to Zero) ............................... 3-13

3.8.5 Calibrating the Odometer Using a Measured Mile ....................................................... 3-14

3.8.6 Viewing the Locomotive Wheel Size ............................................................................ 3-15

3.8.7 Changing the Locomotive Wheel Size from the Front Panel ........................................ 3-15

3.8.8 Viewing Train Acceleration ........................................................................................... 3-16

3.8.9 Viewing the Train Speed .............................................................................................. 3-16

3.8.9.1 Setting and Using English or Metric Units .................................................................... 3-16

3.8.10 Display Secondary Air Pressure ................................................................................... 3-17

3.8.11 Disarming the CDU ...................................................................................................... 3-18

3.8.12 Scanning for Incoming ID Codes .................................................................................. 3-19

3.8.13 Setting the Sonalert Output Volume ............................................................................. 3-19

3.8.14 Setting the Display Panel Brightness ........................................................................... 3-19

3.8.15 Performing a CDU Self Test ......................................................................................... 3-20

3.9 PERFORMING A LAMP TEST ..................................................................................... 3-20

3.10 ARMING the CDU to an END UNIT ............................................................................. 3-21

3.10.1 Description of Arming Process ..................................................................................... 3-22

3.10.2 Automatic Arming .........................................................................................................3-23

3.11 MOTION INDICATION ................................................................................................. 3-23

3.12 ALARM INDICATIONS ................................................................................................. 3-24

3.12.1 Low Battery .................................................................................................................. 3-24

3.12.2 Rear-to-Front Communications Failure (R TO F FAILURE) ........................................ 3-25

3.12.3 Front-to-Rear Communications Failure (F TO R FAILURE) ........................................ 3-25

3.12.4 ALARM Annunciator ..................................................................................................... 3-26

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TABLE OF CONTE NTS

3.13 EMERGENCY BRAKE APPLICATION ........................................................................3-27

3.14 COMMUNICATION TEST ............................................................................................ 3-28

3.15 AUTOMATIC COMMUNICATION TEST ..................................................................... 3-28

3.16 CDU DATALOGGER PORT ........................................................................................ 3-29

3.16.1 Data Logger Format ..................................................................................................... 3-29

3.16.2 Event Recorder Format ................................................................................................ 3-32

3.16.2.1 Electrical Characteristics ...........................................................................................3-32

3.16.2.2 Data Transfer Protocol .............................................................................................. 3-32

IV CONFIGURATION and DIAGNOSTICS ....................................................................... 4-1

4.0 CONFIGURATION and DIAGNOSTICS ........................................................................ 4-1

4.1 Diagnostic Software ........................................................................................................ 4-1

4.1.1 Running the Diagnostic Software ................................................................................... 4-1

4.2 Main Menu ...................................................................................................................... 4-2

4.3 Diagnostic Items ............................................................................................................. 4-3

4.4 Configuration Items Menu ..............................................................................................4-3

4.4.1 Set ID Code ...4-4

4.4.2 Set One-Way Protocol .................................................................................................... 4-5

4.4.3 Set Two-Way Protocol .................................................................................................... 4-6

4.4.4 Enable Two-Way Mode .................................................................................................. 4-7

4.4.5 Set Low Pressure Threshold .......................................................................................... 4-8

4.4.6 Configure Odometer ....................................................................................................... 4-9

4.4.6.1 Set Type of Units Submenu............................................................................................. 4-9

4.4.6.2 Set Wheel Diameter Submenu ..................................................................................... 4-10

4.4.7 Configure Data Logger ................................................................................................. 4-11

4.4.7.1 Set Protocol ...4-11

4.4.7.2 Set Baud Rate .............................................................................................................. 4-12

4.4.7.3 Set Bits Per Character ..................................................................................................4-12

4.4.7.4 Set Parity .......4-13

4.4.7.5 Set Number of Stop Bits ............................................................................................... 4-13

4.4.8 Configure Armed Status LED ....................................................................................... 4-14

4.4.9 Configure Customer String ........................................................................................... 4-15

4.4.10 Configure Front Panel Menu ........................................................................................ 4-16

4.4.11 Enable Automatic Arming ............................................................................................. 4-17

4.4.12 Set Transmit Power Level ............................................................................................ 4-18

4.4.13 Allow Changing Between One and Two Way Operation............................................... 4-19

4.4.14 Blanking the Function Menu Display During No Activity............................................... 4-20

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TABLE OF CONTE NTS

APPENDIX A SOFTWARE UPGRADES ..................................................................................A-1

A.1 CDU Software Upgrades ................................................................................................A-1

A.2 Cab Unit Flash Loader Program .....................................................................................A-1

A.3 Using “load.exe” .............................................................................................................A-1

A.4 Procedure for Downloading CDU Software Upgrades ...................................................A-2

LIST OF FIGURES & ILLUSTRATIONS

Figure 1-0 Two-Way Telemetry .................................................................................................. 1-1

Figure 1-1 Model 6696 CDU Features & Front Panel Layout .................................................... 1-6

Figure 1-2 Model 6696 CDU Features (Rear Panel View) ........................................................ 1-7

Figure 1-3 Model 6696 CDU Features (Top Internal View) ....................................................... 1-8

Figure 1-4 CDU Model 6696 Functional Block Diagram ............................................................ 1-9

Figure 3-1 CDU Model 6696 Front Panel Layout ....................................................................... 3-2

Figure 3-2 Arming Process....................................................................................................... 3-21

LIST OF TABLES

Table 1 - 1 Inst a lla t i o n P a rt s......................................................................................................... 1-4

Table 1-2 Diagnostic Software Diskette .................................................................................... 1-4

Table 1-3 CDU Specifications .................................................................................................. 1-5

Table 2-1 CDU Powe r Connections............................................................................................ 2-2

Table 2-2 CDU Axle Alte rna to r Connections (Bayonet Twist Lock Type Connector) ................... 2-3

Table 2-3 CDU Axle Alte rna to r Connections (MS Threaded Type Connector) ............................ 2-3

Table 2-4 CDU DATALOGGER Port Connections ..................................................................... 2-4

Table 2-5 CDU Event Recorder Connections ............................................................................ 2-4

Table 3-1 Quick Reference: CDU Function Menus and Display Messages ............................. 3-4

Table 3-2 Quick Reference: CDU Annunciator LEDs ............................................................... 3-5

Table 3-3 Quick Reference: CDU Function Keys .................................................................... 3-7

Table 3-4 English or Metric Units ........................................................................................... 3-16

SM 7063 07/97

vi

1.0 PURPOSE OF MANUAL

SECTION I INTRODUCTIO N

This manual provides general information on the DIGITAIR



End-of-Train Telemetry System and
detailed informat i on on the installation and operation of the Model 6696 Communication Display Unit
(CDU). Refer to Service Manual SM 7064 for detailed Shop Maintenance information.

1.1 GENERAL OVERVIEW



The DIGITAIR

End-of-Train Telemetry System con sists o f a Co mmun icat ion Disp lay Unit (CDU)
mounted in the locomotive cab which communicates via UHF radio with an end-of-train End Unit mounted
on the coupler of the last train car.

The CDU, w hen operating in conjunction with an End Unit such as the DIGITAIR



Model 6695 SBU,
provides the locomotive operator with information about the conditions at the rear of the train that are
important to the operation of the train. The CDU’s major functions include:



A digital display of the brake pipe pressure at the rear of the train.



An indication of motion of the last car (moving/stopped) and its initial direction (forward/reverse).



The End Unit battery status and other warnings about brake pipe pressure.



The On/Off status of the Highly Visible Marker (HVM) light if equipped on the End Unit.



When operating in two-way mode, provides an Emergency braking function from the rear of the train.

The CDU can be configured to support optional functions such as:



A digital d ispla y of the auxilia ry pressure if transmitt ed b y dual pressure type End Units.



A built-in odometer to display the distance traveled by the locomotive, speed, and/or acceleration.

The CDU Model 6696 is compatible with all End Units employing existing protocols such as the
American Association of Railroads (AAR) End-of-Train message protocol. It meets or exceeds the
guidelines of the AAR along with the Federal Railroad Administration (FRA), the Federal
Communications Commission (FCC), Industry Canada (IC), and the Canadian Department of
Communications (DOC) regulations.

LOCOMOTIVE

LAST CAR

UHF RF LINK

450-475 MHz RF L I NK

END UNIT

HVM

BRAKE PIPE AIR

-BRAKE PRESS.

-BATTERY STATUS

-HVM STATUS

-CAR MOTION

-COMMS LINK TEST

-EMERGENCY ACTIVATION

VEHICLE
BATT.

ODOMETER
INPUT (OPT.)

CDU 6696

Figure 1-0. Two-Way Telemetry Functions

SM 7063 07/97 1-1

SECTION I INTRODUCTIO N

1.1.1 CDU FUNCTIO NAL DESCRIPTION

The CDU mounts in the locomotive cab; it connects to an antenna mounted on the roof and to the DC
power system (72 VDC nominal). Separate connectors are provided for connection to the locomotive Axle
Alternator (odometer), a Datalogging device, and a Diagnostic computer.

Since the CDU incorporates all displays, the w a rning beeper, and all controls on its front panel, it should be
mounted where it is highly visible and within easy reach of the locomotive operator (i.e., on the control
stand or in a console).

The CDU transmits and receives data to/from the End Unit using a UHF radio transceiver. The transmitter
frequency is typically 452.9375 MHz and the receiver frequency is typically 457.9375 MHz. When the CDU
receives a message from the End Unit, it processes the information and displays it on various LED
displays and annunciators. The CDU is typically in the receive mode of operation ready to accept and
display messages from an End Unit. When the COMM ARM key or EMERGENCY switch is pressed, the
CDU switches to transmit mode, sends the respective command message, and then immediately returns
to receive mode.

If the optional Arming feature (a security function) is enabled in the CDU, the Emergency transmission is
sent only if the CDU has been “Armed” to the ID code of its matched End Unit.

If the CDU is connected to the locomotive axle alternator, it can be configured for various odometer related
functions. These include the capability to display the d istance traveled by the locomotive, a train length
function whereby the length of the train can be entered and stored and then be used as a preset distance
counter, and the display of train speed and/or acceleration. The CDU has built -in fun ct ion s to a llow
calibration of the odometer to compensate for locomotive wheel size variations. In addition, the CDU can
be configured to display odometer measurements in English or Metric units. Refer to Section III for
operating instructions.

An RS-232 serial port used for datalogger and event recorder functions is a standard feature of the CDU.
Whenever new information appears on the display or a transmission is received from the End Unit, the
data is transmitted to this port so that it may be stored in a computer, event recorder, or be directly printed.

The CDU also supports an RS-232 serial port for diagnostics, unit configuration, and download of software
upgrades. These are all performed via a standard DOS-compatible personal computer (PC).

As an additional safety feature, the CDU also displays the status of the emergency brake valve drive
circuitry u sed in t he En d Un it. It will show a “Va lve Fa il” a larm in dica tion if a p rob lem is d ete cte d .

1.2 DEFINITIO N of TERMS

The following terms and abbreviations are used throughout this manual:
EOT - End-o

f-Train: Refers to an End-of-Train telemetry system comprised of a Cab Unit mounted in

the locomotive and an End Unit mounted on the coupler of the last train car.

CDU - Communication D

isplay Unit: A two-way End-of-Train Cab Unit (e .g., CDU Model 6696).

SBU - Sense and Brake Unit - Any generic two-way End-of-Train End Unit capable of remote

Emergency Brake Applications.

HVM - Highly Visible Marking Device - The Marker Light portion of the End Unit; an FRA approved

flashing light used to mark the end of the train.

SM 7063 07/97 1-2

SECTION I INTRODUCTIO N

1.3 PATENTS AND TRADEMARKS

Patents have been granted or are pending on items described in this manual. In the USA, the
following patents have been applied for or have been granted:

Railway Brake Pressure Monitor, Patent 4,487,060
Coupler Mount Assembly, Patent 4,520,662
Rechargeable Battery Pack, Patent 4,554,221

Similar patent applications have been made or are being made in Canada and Australia. DIGITAIR
is a registered trademark of Union Switch & Signal Inc.

1.4 R.A.I.L. TEAM AND TECHNICAL SUPPORT

Rapid Action Information Link (R.A.I.L.) Team

The

is comprised of a group of

experienced product and application engineers ready to assist and resolve any



technical issues concerning DIGITAIR

End-of-Train equipment or any US&S

product.
Any questions regarding the contents of this Service Manual can be answered

by contacting the R.A.I.L. Team toll free at 1-800-652-7276 or via Internet e­mail at: [e-mail].

1.5 CDU ORDERING INFORMATION

The follow ing ord erin g in forma tion can b e u sed to sele ct va riou s co nfigu rat ion s of th e CDU M odel 6696.
Please contact US&S Customer Service at 1-800-652-7276 or your US&S Sales Representative for
technical information, pricing, and additional sales information.

1.5.1 Mounting and Hardware Options

1. CDU Mounting Options:

®

a) Standard Mounting Tray (Typically mounts on locomotive Control Stand)
b) AAR Clean Cab Enclosure (Industry standard radio enclosure)
c) Custom Mounts (per Railway requirements)

2. Connector Styles (Power and Axle Alternator):

a) Bayonet Twist Lock (ITT Cannon)
b) MS Threaded Style (Bendix/Amphenol)
c) MS Bay onet Sty le (Bendix/Amphenol)

3. Front Panel “ARMED” Status LED Markings:

a) No ARMED Status LED
b) Status LED Marked “ARMED”
c) Status LED Marked “NOT ARMED”

SM 7063 07/97 1-3

SECTION I INTRODUCTIO N

1.5.2 Parts Used for Installation

Table 1-1 below lists parts used for installation which may be ordered separately from the CDU.

Description Part Number

Installation Kit Complete, Mounting Tray Style X451646-9801
Installation Kit Complete, AAR Clean Cab Style 116-5016-00

CDU Mounting Tray 150-0128-00
CDU Odomete r Cab le N451805-1201
CDU Powe r Ca ble , B a yonet Connector, 72 VDC N451883-0401
CDU Powe r Ca ble , B a yonet Connector, 12 VDC N451883-1401
CDU Antenna 472-0017-00
CDU Antenna Cable Kit 170-0842-00

Table 1-1. Installation Parts

1.5.3 Diagnostic Software Dis k

The CDU does not rely on a dedicated external device for system diagnostics. All of the unit diagnostic
tests and configuration functions are included on a Diagnostics Software Disk that runs on a standard
DOS-compatible personal computer (PC) which plugs into the CDU’s rear mounted Diagnostic Port.

The Diagnostic Software has been designed to permit easy customization of the operation of the CDU.
Most of the variable default values and functions are user selectable, set by the factory at purchase
time, or by railway technicians via a PC computer after purchase. The Diagnostic Software program on
the disk is named

The Diagnostic Software Disk can be ordered under the following part numbers:

1.5.4 CDU Executable Software Disk

The CDU uses a FLASH type programmable non-volatile memory chip to store its application software
as opposed to a standard EPROM. This eliminates the need to disassemble the unit and physically
replace the EPROM in the event that software upgrades are issued.

The CDU Executable Software disk allows the user to download CDU software upgrades into the
CDU’s internal FL ASH memory. This disk con t ains two files; (1) th e latest upgrade version of the CDU
executable software named

“load.exe”

. The use of this disk is described in Appendix A.

“diagunit.exe”

Description Part Number

3.5” Diskette N451232-1264

5.25” Diskette N451232-1265

and its use is described in Sections IV.

Table 1-2. Diagnostic Software Diskette

“cdu.hex”

, and (2) the Cab Unit Flash Loader program named

The CDU Executable Software disk is available on a 3.5” diskette under US&S part number N451232-

0821.

SM 7063 07/97 1-4

SECTION I INTRODUCTIO N

1.6 CDU SPECIFICATIONS

Parameter Specification

Physical:

Overall Dimensions H = 4.25”, W = 10.75”, D = 8.25”
Weight 9 lbs

Environmental:

Operating Temperature Range
Storage Temperature Range
Humidity
Vibration - any axis, peak-to-peak 5 - 15 Hz: 0.5g; 15 - 500Hz: 3.0 g

Shock - (11 msec triangular, 3 planes) 20 g
Altitude -300 to +15000 feet MSL

0C to +60C

-55C to +100C
95% non-condensing at 40 C, 96 hour exposure

Power Requirements:

72 VDC Locomotive Power, Floating 58 VDC (min); 72 VDC (nom); 86VDC (max)
Current Consumption @ 72 VDC 0.35 A (typ); 1.5 A (max)

13.6 VDC Power Input (Negative Ground) 13.6 VDC (min/nom); 14.3 (max)
Current Consumption @ 13.6 VDC 1.0 A (typ); 4.0 (max)

Radio Transceiver:

Transmit Frequency 452.9375 MHz (AAR typ); 450 - 475 MHz (available)
Transmit Power 2 Watts (standard); 4 Watts (Configurable)
Transmit Frequency Stability 5 ppm
Emission 16K0F2D
Deviation (at 1200 Hz) 3.3 KHz

Receive Frequency 457.9375 MHz (AAR typ); 450 - 475 MHz (available)
Receive Sensitivity (-12 dB SINAD) 0.45 uV (max)
Receive Frequency Stability 10 ppm (ma x)
Selectivity 60 dB (min)
Intermodulation Immunity 60 dB (min)
Spurious Rejection 55 dB (min)
Image Rejection 50 dB (min)

Odometer Interface:

Input from Axle Alternator 20 ppr or 60 ppr
Wheel Diameter Calibration Range 34.00” (min); 40.00” (default); 46.00” (max)

Datalogger Interface:

Asynchronous Serial Data Rate 300 to 9600 Baud
Voltage Level EIA RS-232C
Data Format Configurable Parity, Stop Bits, and Data Bits

PC Diagnostic Interface:

Asynchronous Serial Data Rate 9600 Baud, 1 Stop Bit, 8 Data Bits
Voltage Level EIA RS-232C

Table 1-3. CDU Specifications

SM 7063 07/97 1-5

SECTION I INTRODUCTIO N

I

1.7 CDU MAJOR COMPONENTS

The photo and illustration below shows the CDU M odel 6696 ex ternal components and ty pical front
panel layout.

Union Switch & Signal Inc.

D = 85323

PRESSURE

MARKER

ON

LOW

BATTERY

MOVING

STOPPED

R TO F

FAILURE

F TO R

FAILURE

ALARM

COMM

ARM





CANCEL





SET





MENU

UP





MENU
DOWN

E
M
E
R
G
E
N
C
Y

Figure 1-1. - Model 6696 CDU Features & Front Panel Layout

1.7.1 CDU Unit Housing

The CDU Model 6696 uses the same exterior aluminum alloy housing used on previous versions of



DIGITAIR

Cab Units. This helps ensure the Model 6696 will fit into, and be compatible with, existing
locomotive installations. Two mounting configurations are available; a Standard Mounting Tray style
mount, and an AAR Clean Cab Enclosure style mount.

The CDU is designed to be lightweight (9 pounds) and incorporates a fold-out carrying handle for
transporting the unit to the locomotive or between locomotives.

SM 7063 07/97 1-6

SECTION I INTRODUCTIO N

1.7.2 CDU Rear Panel

The photo below shows a typical rear panel connector layout for the CDU Model 6696.

Figure 1-2. Model 6696 CDU Features (Rear Panel View)

The CDU supports connectors on its rear panel for the following functions:



Power:



Axle Alt.:



Antenna:



Datalogger:



Diag:

Connects to a PC serial port for diagnostic and configuration purposes.

Mounting hardware on the rear panel includes:



Screw Latch:



Lock Bracket:

72 VDC nominal locomotive power or 13.6 VDC nominal for mobile use.
Connects to locomotive’s axle alternator for Odometer related functions.

Connects to roof mounted locomotive UHF antenna.

Can be interfaced to an event recorder, computer, or serial printer.

Spring loaded latch secures the CDU to the Mounting Tray or AAR Clean Cab
Enclosure.

Provides a means for locking the CDU to th e M ounting Tray using a padlock.

SM 7063 07/97 1-7

SECTION I INTRODUCTIO N

1.7.3 CDU Major Assemblies

The photo below shows a top view of the CDU with its cover removed exposing the ma jor assemblies.
The unit has been designed using a modular approach for ease of production and user maintenance.

Figure 1-3. Model 6696 CDU Features (Top Int ernal View)

The CDU is comprised of the followin g three (3) major sub-assemblies:



Front Panel Assembly:



Rear Panel Assembly:



Base Assembly:

SM 7063 07/97 1-8

Contains the Processor Board, LED Display Driver Board, Display Panel, and

Emergency Switch Assembly.

Contains the Interface Connectors and UHF Transceiver Module.

Contains the Bottom Housing, Power Supply Circuitry, and serves as the
base into which the Front and Rear Panel Assembly plug.

SECTION I INTRODUCTIO N

1.8 CDU FUNCTIONAL BLOCK DIAGRAM

The following is a functional block diagram of the CDU Model 6696 showing its major sub-systems and
external interfaces.

Transceiver

Transmit

Audio

MODEM

Receive

Audio

General Digital Inputs

Front Panel Switches

Reverser Switch Inputs

20/60 PPR Axle Alter. Select

Axle Alternator Input

Key XMTR

Sleep

Carrier Detect

12

2

10

2

1
1

Internal

UART

CPU

Parameter

EEPROM

FLASH

RAM

Diagnostics and Calibration

Information

DUAL

CHANNEL

UART

System

RAM

Boot

EPROM

Lap-top

for Diagnostics

Datalogger or

Event Recorder Device

Front Panel Displays

Power Supply

4/3/96

Cab Unit Blo c k Diagram

or

+12VDC +74VDC

or

Figure 1-4. CDU Model 6696 Functional Block Diagram

SM 7063 07/97 1-9

SECTION I INTRODUCTIO N

SM 7063 07/97 1-10

SECTION II INSTALLATION

2.0 INSTALLATION OF THE CDU

This section d eta ils th e in sta llat ion of a CDU into th e lo co motive cab e nviro nme nt . Two versions of CDU
mounting arrangements are available:

1. CDU mounted on a Mounting Tray.

2. CDU mounted in an AAR Clean Cab Enclosure.

2.1 General Description

The locomotive equipment comprises a Model 6696 Communication Display Unit (CDU). Available
accessories include (refer to Table 1.1 for part numbers):



Complete Installation Kits



Mounting Tray



Antenna Cable Kit



UHF Antenna



Power Cable Assemblies



Odometer Cable Assemblies



Diagnostic Software Disk
The Power and Odometer cables may be purchased separately or fabricated by the Railroad.
The locomotive antenna and antenna cable may be purchased from US&S or supplied by the Railroad.

The cable must employ a PL-259 style UHF connector. The antenna itself must be 1/4 wave whip or a low
profile slot-type antenna.

If desired, the Railroad may supply a padlock to lock the CDU into positio n o n th e M ounting Tray.

2.2 Preparing the Locomotive

This section provides information on preparing a locomotive for installation of the CDU. Once the
locomotive has been equipped as described in this section, the CDU may be installed as instructed in 2.4.

Preparing the locomotive involves equipping it with either a Mounting Tray or AAR Clean Cab Enclosure
and wiring the required electrical connections. Note that some locomotives may already have this
equipment installed.

2.2.1 Mounting Tray Installation

The Mounting Tray is typically located on the control stand and provides the CDU with a mechanical quick­disconnect base for easy application and removal. The Mounting Tray is affixed to the control stand as
follows:

1. Using a Mounting Tray as a template, mark the control stand for drilling.

2. Drill holes of 1/ 4" dia met er.

3.Attach the Mounting Tray to the control stand using appropriate bolts, nuts, and lockwashers (supplied by

the Railway).

SM 7063 07/97 2-1

SECTION II INSTALLATION

2.2.2 AAR Clean Cab Enclosure

Installation of an industry standard AAR Clean Cab Enclosure in the locomotive is the responsibility of th e
Railway.

2.3 Installing the CDU Cable s

This section details the installation of the Power and Odometer cables required to connect the CDU to the
locomotive. The cables and their respective part numbers are listed in Table 1-1 in the previous section.

2.3.1 Power Cable Installation

For most installations, one of two types of power cable assemblies are used to connect the CDU to the
locomotive DC power system. One is a 5-pin Bayonet Twist Lock type (CA) connector and the other is a 4­pin MS Threaded type connector. In both cases, the cable assemblies are supplied with the connector
pre-mounted on one end of the cable, with the other end left unterminated.

CAUTION

Non-standard cables, or those supplied by the Railroad, may employ different
color codes than those used by US&S. Refer to the connector pin assignments
in this manual or consult US&S Customer Service at 1-800-652-7276 for further
technical assistance, if required.

Cut the cable to the desired length. Strip and install whatever spade lug, tab, or other contact is required for
the locomotive. The three conductor cable should be wired per the table below:

Pin Conductor Bayonet (CA) Ty pe Conne ctor MS Threaded Type Connector

A Black + 72 VDC Locomotive Power + 72 VDC Locomotive Power
B N.C. + 13.6 VDC Mobile Power 13.6 VDC Mobile Power Ground
C White 72 VDC Locomotive Power Return 72 VDC Locomotive Power Return
D N.C. 13.6 VDC Mobile Power Ground + 13.6 VDC Mobile Power
E Green Chassis Not Used

Note: N.C. = Not Connected

Table 2-1. CDU Po wer Connections

2.3.2 Odometer (Axle Alternator) Cable Installation

Two standard Odometer Cables are available. Each consists of a dual twisted pair, individually shielded
cable with either a 6-pin Bayonet Twist Lock type (CA) connector or 6-pin MS Threaded type connector on
one end. The other end is unterminated.

CAUTION

Non-standard cables, or those supplied by the Railroad, may employ different
color codes than those used by US&S. Refer to the connector pin assignments
in this manual or consult US&S Customer Service at 1-800-652-7276 for further
technical assistance, if required.

SM 7063 07/97 2-2

SECTION II INSTALLATION

Cut the odometer cable to the desired length. Strip and install whatever spade lug, tab, or other contact is
required for the locomotive. The shield wire(s) connects to the CDU chassis at the connector end; cut the
shield wire(s) at the locomotive end and leave unconnected. The cables should be wired per the tables
below.

For the Bayonet Twist Lock type (CA) connector, the pin assignments and cable color codes are:

Pin Conductor Bayonet Twist Lock Type (CA ) Conne ctor

A RED-1 Axle Alternator Signal Input
B RED-2 Direction A (TL8)
C BLK-2 Direction B (TL9)
D See notes * 20 / 60 PPR Return
E See notes * 20 / 60 PPR Select
F BLK-1 Axle Alternator Signal Return

Table 2-2. CDU Ax le Alt ern a to r Connections (Bayonet Twist Lock Type Connector)

* Notes:



PPR = Pulses Per Locomotive Wheel Revolution



For 20 PPR operation, retain jumper between pins D and E.



For 60 PPR operation, cut jumper between pins D and E.

For the MS Threaded type connector, the pin assignments and cable color codes are:

Pin Conductor MS Threaded Type Connector

A RED-1 Axle Alternator Signal Input
B BLK-1 Axle Alternator Signal Return
C See notes * 20 / 60 PPR Select
D See notes * 20 / 60 PPR Return
E RED-2 Direction A (TL8)
F BLK-2 Direction B (TL9)

Table 2-3. CDU Ax le Alt ern a to r Connections (MS Threaded Type Connector)

* Notes:



PPR = Pulses Per Locomotive Wheel Revolution



For 20 PPR operation, retain jumper between pins C and D.



For 60 PPR operation, cut jumper between pins C and D.

NOTE

When routing the odometer cable from the axle alternator to the CDU, ensure
that it is kept c lea r o f lo c o mo tiv e "d irty" (noisy) wiring.

SM 7063 07/97 2-3

SECTION II INSTALLATION

2.3.3 Antenna and Cable I nsta lla tion

Install the UHF antenna at least 6" from the edge of the locomotive roof and at least 12" from any other
fixture on the roof. Try to keep the cable run as short as possible.

If interference from a nearby transmitting antenna (e.g. voice radio) is likely to be a problem, locate the
antenna as far away as possible.

Affix the antenna cable in place and terminate it in a PL-259 UHF connector. Use only a high quality low
loss antenna cable such as RG-213/U.

2.3.4 CDU Datalogger Connector

All CDUs are equipped with a DATALOGGER port connector. This is a 25-pin serial RS-232/C “D” type
connector mounted on the rear panel. Four of the 25 pins are used as listed in the table below:

Pin DATALOGGER Conne ctor

1 Chassis Ground (Shield)
2 Receive Data (RX DATA)
3 Transmit Data (TX DATA)
7 Signal Ground

Table 2-4. CDU DATALOGGER Port Connections

The connector is designed to operate as a DCE type serial port where pin 2 is used to receive data
from a remote serial device and pin 3 is used to transmit data to a remote serial device. This allows for
the use of a “straight-through” (not a null modem) type serial cable.

Note that Chassis Ground and Signal Ground are isolated from each other. The serial
communications parameters (baud rate, etc.) are configurable via a Diagnostic PC as described in
Section IV of this manual.

2.3.5 Event Recorder Connector

For CDUs equipped with a circular Event Recorder connector, the connector pin assignments are as
follows:

Pin Event Recorder Connector

A Receive Data (RX DATA)
B Transmit Data (TX DATA)
C Signal Common
D Chassis (SHIELD)
E Spare 1
F Spare 2

Table 2-5. CDU Event Recorder Connections

SM 7063 07/97 2-4

SECTION II INSTALLATION

2.4 MOUNTING THE CDU

This section details mounting the CDU onto the Mounting Tray or in the AAR Clean Cab Enclosure.

2.4.1 72 VDC / 12 VDC Power Selection Jumper (JP1)

The CDU can be powe red from either the standard 72 VDC locomotive power system or a 13.6 VDC
(nominal) power source such as an automobile lighter socket. An internal Power Selection Jumper (JP1)
located on the Base Assembly allows the user to select one power source or the other.

The CDU is shipped with thi s j umper s e t to the 72 V pos iti on

.

To change the Power Selection Jumper setting, simply remove the CDU’s top cover, remove the jump er
plug, and place it in the desired position as marked on the PCB silk-screen. Replace the top cover.

2.4.2 Installing the CDU onto a Mounting Tray

CAUTION

Prior to connecting any cables to the CDU, it is recommended that the
locomotive Radio Circuit Breaker be turned OFF.

a) Slide the CDU into th e keyhole slots in th e Mounting Tray.
b) Engage the screw latch at the rear of the CDU.
c) Tighten the scre w la tc h u nt il th e CDU is firmly in place. Do n ot ov ertig h te n. Pa dlo ck th e u nit , if de sire d.
d) Connect the CDU Power cable to the pow er connector on the CDU.
e) If applicable, connect the CDU Odometer cable to the Axle Alt connector on the CDU.
f) If applicable, connect the CDU Datalogger/Event Recorder cable to the Datalogger/Event Recorder

connector on the CDU.

g) Connect the Antenna cable to the mating RF connector on the CDU.

2.4.3 Installing the CDU into an A AR Clean Cab Enclosure

a) Slide the CDU into t he e nclo su re from t he ba ck.
b) Engage the screw latch at the rear of the CDU.
c) Tighten the screw latch until th e CDU is firmly in pla ce . Do no t o vertig ht en .
d) Connect the CDU Power cable to the pow er connector on the CDU.
e) If applicable, connect the CDU Odometer cable to the Axle Alt connector on the CDU.
f) If applicable, connect the CDU Datalogger/Event Recorder cable to the Datalogger/Event Recorder

connector on the CDU.

g) Connect the Antenna cable to the mating RF connector on the CDU.

SM 7063 07/97 2-5

SECTION II INSTALLATION

2.5 BRIEF OPERATIONAL TEST OF THE CDU

Upon receipt of a new CDU, it is recommended that the unit be briefly tested as described in this section to
verify correct operation. This is performed in conjunction with a known operational End Unit.

2.5.1 CDU Power-Up Sequence

Upon CDU power-up, verify th at the follow ing displa y sequence is indicated on the CDU’s Front Panel:



The 32-Character LED Display (
accompanied by a beep tone. All other displays should be off.



The Brake Pressure Display shows three dashes



The 8-character LED Display (

“ID=85323”



Function Menu Display

The



“Union Switch & Signal Inc .”



“Version: Revision X”



“Boot PROM Version: REV X”



“RAM test: passed”



“ROM test: passed”



“EEPROM test: passed”



“USC test: passed”



“Boot ROM test: passed”



“Self Test Complete: passed”



After completion of the above test sequence, the CDU reverts to its top (first ) funct ion menu item
where the

).

Function Menu Display

Function Menu Display

“- - -”

ID Code Display

continues showing the following message sequence:

(by default) or a customer specified character string.

.

.

.

.

.

.

.

.

shows (with the example ID code):

) shows the currently stored End Unit ID code (e.g.,

) shows

.

“Self Test in progress”

“ Change ID: 85323 “

with the first digit flashing, ready for input by the operator.



If a power-up diagnostic test fails, this will be indicated as such, and the power-up sequence w ill ha lt.
Note the specific test that has failed and contact US&S Customer Service at 1-800-652-7276 for
technical assistance or warranty repair instructions.

SM 7063 07/97 2-6

SECTION II INSTALLATION

2.5.2 CDU Functional Check

Perform the follo w in g b as ic step s t o ve rify th at th e CDU is fun ctio nin g co rre ctly:



Obtain a known operational End Unit. It may be operated within the locomotive without damage and no

pressurized air is necessary.



Power-up the CDU, observe it comple tes its pow e r-on sequence, and then enter the ID code of the End

Unit into th e CDU.

NOTE

If the CDU is configured to support the “Arming” security feature, it will prompt
the user to perform the Arming process as described in Section III. IT IS NOT
NECESSARY TO DO THIS IN ORDER TO PERFORM A FUNCTIONAL CHECK OF
THE CDU.



Press the external TEST button to activate the End Unit and cause it to transmit a message. Observe

the Brake Pressure Display on the CDU. With no air pressure applied to the End Unit, the pressure

reading should change from

“- - -”

to

“ 0”

psi. This will be accompanied by a Low Pressure Alarm

since the pressure is below the standard 45 psig threshold and is normal.



Press the

LED Display briefly shows

COMM ARM

key on t he CDU to initia te an RF lin k check. Ob serve th e CDU’s 3 2-ch ara cte r

“WAI TING FOR REP LY”

, shortly followed by

“COMM TEST OK”

confirms correct operation of the CDU’s RF transceiver and associated control circuits.

Note:

The rightmost decimal point in the Brake Pressure Display serves as an indicator to show that a
message has been received from the End Unit. It will briefly lig ht ea ch time a me ssage is
received.



Verify the integrity of the Emergency Switch contacts by activating the switch and observing a

“SYSTEM IS NOT ARMED”



Perform a

LAMP TEST

simultaneously pressing the



Observe th at ea ch of th e CDU’s n in e (9 ) Con tro l P ush b ut to ns are illumin a te d (i. e. , b a cklit).

message on the Function Menu Display.

to verify that all of the LED display segments light. This is done by

MENU UP

MENU DOWN

and

keys as marked on the front panel .

. This

SM 7063 07/97 2-7

SECTION II INSTALLATION

SM 7063 07/97 2-8

SECTION III OPERATION

3.0 CDU OPERATING INSTRUCTIONS

This section provides detaile d information on the CDU’s various operating modes and functions, and
how each one is used.

3.1 Purpose and Use of ID Code

Each End Unit has a unique 5-digit numeric Identification Code (ID Code) assigned by the AAR
“Central Train Information System Clearinghouse”. The ID Code is programmed into each End Unit
and is a part of every message it transmits. This code is permanently marked on a label or plate
mounted on the outside of the End Unit. The ID code entered into the CDU must match the End Unit
ID code before EOT messages can be received and displayed. Likewise, the End Unit will only accept
and process commands from a CDU with the matching ID code.

ID Code Must Match

Union Switch & Signal Inc.

PRESSURE

MARKER

ON

LOW

BATTERY

MOVING

STOPPED

ARMED

R TO F

FAILURE

F TO R

FAILURE

ALARM

ID = 85323

COMM

ARM

SET





CANCEL

E
M

MENU

UP





MENU
DOWN

E
R
G
E
N
C
Y









Cab Unit (CDU Model 6696)

Typical End Unit

3.2 Radio Communica tion Channel

Since all End Units transmit on the same radio channel frequency (typically 457.9375 MHz), the ID
code is the only way the CDU can d istinguish one End Unit from another. In a similar fashion, all
CDUs transmit on the same radio channel frequency (typically 452.9375 MHz) and the End Unit relies
on the ID code to distinguish between commands sent by the CDU.

CAUTION

Ensure the ID code entered into the CDU matches that of the End Unit installed
on the respective train before actuating the EMERGENCY switch.

With the correct ID code entered, the CDU is ready to begin receiving messages for display

SM 7063 07/97 3-1

.