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xxxi
SIG-00-22-02 JUNE 2022 (Revised September 2022)
Version: B.1
Highway-Railroad Grade
Crossing Advance Warning Sign:
A traffic control sign (round yellow sign with RR and a black X) placed by the
highway agency in advance of many highway-railroad grade crossings
Healthy:
The GCP system, modules, and track circuit are operating as intended. Health
is generally indicated by a yellow LED flashing at 1 Hz (approximately the
same flash rate as the FLASH SYNC on a controller or a flashing light signal).
Unhealthy conditions are indicated by faster flash rates (2 Hz and 4 Hz) or a
dark Health LED.
Hz:
Hertz
– Common reference for cycles per second or flashes per
second.
iLOD:
Intelligent Light Out Detector
– used for measuring lamp current.
Interconnection:
The electrical connection between the railroad active warning system and the
traffic signal controller for the purpose of preemption.
IO or I/O:
Input/Output
ISL:
Island
ISL CAL:
Island calibration
kHz:
Kilohertz
– 1000 Hz or 1000 cycles per second.
LAMP 1 VOLTAGE:
The voltage on 1L1 or 2L1 lamp output of the crossing controller module,
SSCC IIIi.
LAMP 2 VOLTAGE:
The voltage on the lamp 1L2 or 2L2 lamp output of the crossing controller
module, SSCC IIIi.
LAN:
Local Area Network
– A limited network where the data transfer medium
is generally wires or cable.
LOS:
Loss of Shunt
– Commonly due to rust and/or rail contamination. LOS
timers provide a pick up delay function.
MAIN:
The primary GCP Modules (CPU, PSO, and RIO Modules) that are in a dual
GCP chassis.
MBT
Abbreviation for Master Boot file.
MCF:
Module Configuration File
– The GCP application logic file.
MEF:
Module Executable File
– The GCP executive software program.
Module
Physical package including PCBs and input/output terminals for connecting to
external devices and equipment.
MTSS:
Mini Trackside Sensor
– A device located in the gate mechanism that
combines input information from gate contacts, bell, and gate tip
sensor and sends the information to the SEAR IIi.