Specifications

Engineering Standard –NSW
Signalling SMS 02
Cerberus Level Crossing Monitor Equipment
March 2005 Version 1.2 © Australian Rail Track Corporation Page 82 of 118
This document is uncontrolled when printed.
Variable names can not include white space characters like tabs and
spaces. If a space is desired in a name then it is recommended to use
the underscore character "_" instead.
Variable names can be up to 20 characters long and are case
sensitive.
7.1.2.3 Variable Types
The level crossing monitor supports the following variable types:
 Input
 Output
 Intermediate
 Special Intermediate
 Timer
 Special Timer
 Lamp
 Battery
An input variable directly reflects the state of a digital input.
An output variable directly reflect the state to which a digital output is
set.
An intermediate variable is an internal state of the level crossing
monitor which is controlled by a logical relationship of inputs and
outputs.
A special intermediate variable is an internal state of the level
crossing monitor which is directly controlled by or is used by the level
crossing monitor software.
An timer variable is an internal state of the level crossing monitor
which is controlled by a logical relationship of inputs and outputs and
the length of time the state is maintained.
An special timer variable is an internal state of the level crossing
monitor which is controlled by a logical relationship of inputs and
outputs and the length of time the state is maintained and is directly
used by the level crossing monitor software.
A Lamp variable reflects the state of the level crossing highway
lamps.
A Battery variable reflects the state of the level crossing battery.