COPYRIGHTED AATC SPREAD SPECTRUM RADIO User Manual
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USER MANUAL
FOR
AATC SPREAD SPECTRUM RADIO
HARMON INDUSTRIES, INC
GRAIN VALLEY, MO.
Copyright 2000 Harmon Industries Inc.
All Rights Reserved
The contents of this document may not be reproduced in whole or part
without the written consent of the copyright owner.
COPYRIGHTED AATC SPREAD SPECTRUM RADIO User Manual
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TABLE OF CONTENTS
COPYRIGHTED AATC SPREAD SPECTRUM RADIO User Manual
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SCOPE
This User Manual describes the Harmon Advanced Automatic Train Control (AATC)
Spread Spectrum Radio (SSR) portion of the AATC Radio Set (RS), its installation, and
conditions of usage.
APPLICABLE DOCUMENTS
The following Government regulations form a part of this User Manual to the extent
specified herein. In the event of a conflict between the regulations referenced herein and
the contents of this manual, the regulations shall be considered a superseding
requirement.
Title 29, Code of Federal Occupational Safety and Health Standards
Regulations, Chapter XVII
Part 1910, Subpart G, I, & L
Title 47, Code of Federal Federal Communication Commission Rules
Regulations, Part 15,
Subpart C
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Advanced Automatic Train Control Spread Spectrum Radio
(AATC-SSR) DESCRIPTION
AATC-SSR Definition
The AATC-SSR is a multi-functional digital data transmitter-receiver used for digital
data communication and range measurement. The AATC-SSR with suitable antenna and
mounting/installation kits is a Radio Set (RS) and can be used in a variety of rail vehicle
and wayside configurations. The AATC-SSR is identical in all RS configurations. Only
the differences in the mounting and installation kit (Antenna, Product Identification
Module (PIM), and mounting) define a specific RS configuration and it’s use. The
Product Identification Module is a serial electrically erasable programmable read only
memory (EEPROM) which provides the radio with it’s configuration type i.e. vehicle, or
wayside radio. The AATC-SSR is designed specifically for the railroad environment and
requires professional installation and operation.
AATC-SSR Operation
The AATC-SSR provides for data exchange between RSs, between the AATC-SSR and a
Train Controller, and between the AATC-SSR and a Station Computer. The AATC-SSR
has serial interface capability to a Global Positioning System (GPS) Receiver and the
Radio Test Set (RTS), a specialized test equipment.
The AATC-SSR operation is controlled by firmware (embedded software). The AATCSSR hardware, in combination with this firmware, is designed for operation in a
communications network of similar AATC-SSRs to perform train control or other similar
applications. A network can contain as few as two AATC-SSRs or as many as several
hundred AATC-SSRs. The firmware is specifically designed to support networks of
AATC-SSRs spread out along railways or tunnels, where multiple radio frequency (RF)
links may need to be cascaded to provide communications from a source to a remote
destination. Highly reliable communications is provided through a variety of techniques
including spread spectrum and redundant RF channels.
Using the RF communications signals, the AATC-SSRs cooperatively measure the range
between pairs of AATC-SSRs. The range measurements are reported to a control station,
which is connected to one of the AATC-SSRs in a network, and the Control Station can
use these ranges to establish and track the locations of AATC-SSR equipped vehicles.
The AATC-SSR operates in the 2400 MHz to 2483.5 MHz frequency band. Its transmit
center frequency can be controlled to be anywhere from 2423.75 MHz to 2462.75 MHz
in 1 MHz steps. The AATC-SSRs share the RF band using a combination of time
division, frequency division, and code division multiple access techniques. The
communications network structure is managed by a control station computer, which
assigns time and frequency resources to each of the AATC-SSRs.
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The AATC-SSR consists of three major functional modules and the external interfaces shown in Figure 1.
AATC-SSR
POWER
INTERFACE
RFA
FUNCTION
SMP FUNCTION
External Physical Interfaces
POWER
DISTRIBUTION
FUNCTION
SP
FUNCTION
T&C
FUNCTION
TO ALL
FUNCTIONS
MV
FUNCTION
FUNCTION
MP
Figure 1 AATC-SSR Block Diagram
FRONT
PANEL
FUNCTION
ANTENNA
INTERFACE
SERIAL
INTERFACE
INDICATORS
RADIO TEST
SET
The AATC-SSR implements the following interfaces, shown in Figure 1. The Power Interface is located on
the rear of the unit while the all other interfaces are located on the front of the AATC-SSR. The operator
interface allows the operator to monitor operation of the AATC-SSR. The remaining interfaces are external
connections for the Antenna, Serial Interface (GPS Receiver, Train Controller or Station Computer), Radio
Test Set, and Power.
Operator Interface
The AATC-SSR provides the operator with the following indicators visible from either the top or
front of the AATC-SSR:
Power
The POWER indicator is a green LED which provides the operator with an
indication that proper power is applied to the AATC-SSR.
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Fault
The FAULT indicator is a red LED which provides the operator with an indication that the
AATC-SSR’s firmware has encountered a failure and is not ready for operation. This indicator is
momentarily turned on during power –up.
Mode
The MODE indicator is a yellow LED. The indicator provides the following
indications:
In Power Up mode, during the operational checks, the indicator will be ON. Otherwise,
the indicator will, under firmware control, blink ON and OFF in accordance with the
following ratios:
Net Acquisition 7 ON/ 1 OFF
Time Sync 3 ON/ 1 OFF
Time Stabilized 1 ON/ 1 OFF
A Assignment Received 1 ON/ 3 OFF
B Assignment Received 1 ON/ 7 OFF
Both Assignments Received 1 ON/ 15 OFF
The minimum on or off period is nominally 0.5 seconds.
Serial Interface
The Serial Interface shall include the following types of interface:
a) An RS 232 full duplex link for interfacing the AATC-SSR and GPS Receiver.
b) An RS 485 full duplex link for interfacing the AATC-SSR and Train Controller.
c) An RS 485 full duplex link for interfacing the AATC-SSR and Station Computer..
d) A TTL level signal interface for receiving the GPS 1 PPS timing signal.
e) A TTL level signal interface for the PIM
The 37-pin Serial Interface connector (J1), an Amphenol part number 10-565991-006 or
equivalent, is located on the Front Panel.
Antenna Interface
The Antenna interface allows the connection of the required external antenna. The Antenna
connector (J3) is located on the front of the AATC-SSR and is a 50 Ohm, type N female
connector. Note: This radio must be professionally installed with the appropriate antenna.
Power Interface
The unit requires an attached primary power source (power adapter) for operation. The physical
interface consists of an externally accessible power connector. The unit converts the input direct
current (DC) power to those voltages required by unit electronics.
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Power Input
The AATC-SSR is designed to operate with input power between 21.5VDC and
40VDC. The power input is isolated by at least 1500 VDC between the input
terminals and ground or any set of output terminals
Normal Power Consumption
The total AATC-SSR power consumption is less than 22 watts average when the unit is
operating normally over the input voltage range.
Peak Current Demand
Under all operating conditions, including input line voltage variation, the current
consumed is less than 1.0 Amperes averaged over 1.0 second or longer.
Overvoltage Protection
The power supply shall be capable of withstanding, without damage or abnormal
operation, transient surges applied across the input terminals of the supply. The surge
levels and durations are defined below for a 100 Ohm source impedance
Amplitude (kV)
+/- 5.5
+/- 4.0
+/- 3.0
+/- 1.5
+/- 0.8
Duration (µs)
0.1
1.0
5.0
50.0
100.0
Power Connections
The power connector (J4), an Amphenol 10-565991-003 or equivalent, is located at the
rear of the AATC-SSR. The pin connections are as follows:
Function Pin Number
+VIN L
-VIN M
INSTALLATION
Note: This radio must be professionally installed.
Physical
Refer to the appropriate installation drawing for physical installation.
Cable Connections
Refer to the appropriate installation drawing for the cable connections.
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CAUTION
THIS EQUIPMENT MUST BE PROFESSIONALLY INSTALLED ACCORDING TO
THE INSTALLATION DRAWINGS.
CONDITIONS OF USE
Potential RF Interference
INSTRUCTION TO THE USER
This equipment has been tested and found to comply with the limits for a class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates, uses and can
radiate radio frequency energy and if not installed and used in accordance with the instructions,
may cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment
off and on, the user is encouraged to try to correct the interference by one or more of the
following measures:
§ Reorient or relocate the receiving antenna.
§ Increase the separation between the equipment and the receiver
§ Consult the manufacturer for help.
In order to maintain compliance with FCC regulations, proper cables must be used with this
equipment. Operation with non-approved equipment or improper cables is likely to result in
interference to radio and TV reception. The user is cautioned that changes and modifications
made to the equipment without the approval of the manufacturer could void the user’s authority
to operate this equipment.
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