Specifications

Engineering Standard –NSW
Signalling SMS 02
Cerberus Level Crossing Monitor Equipment
March 2005 Version 1.2 © Australian Rail Track Corporation Page 87 of 118
This document is uncontrolled when printed.
or as a Boolean expression
D = [!A + B] & C
D will be true when C is true and [ A is not true or B is
true]. 7.1.2.8 Steady result expression
Intermediate variables and Output variable are controlled by steady
result expressions. These variables become TRUE (or ON) when the
steady result expression controlling the variable becomes TRUE. The
variables become FALSE (or OFF) when the steady result expression
controlling the variable becomes FALSE.
Steady result expressions have the following
format: x = y
where
x is variable which was declared in the IO list as either an
Intermediate or an Output.
= identifies the expression as being a steady result type of
expression.
B