Specifications

Engineering Standard –NSW
Signalling SMS 02
Cerberus Level Crossing Monitor Equipment
March 2005 Version 1.2 © Australian Rail Track Corporation Page 90 of 118
This document is uncontrolled when printed.
C is the number of lamps expected when the lamps are operating and
the flasher is in the DOWN state. The number must be in the range
of 0 to 4. This is zero when a steady set of lamps is being monitored
u is an Input variable which corresponds to the state of the Flasher
used for the set of lamps. If the particular set of lamps are not
flashed, that is a steady lamp like the tip lamps on booms, then they
are identified by using the word "STEADY" instead of the name of a
flasher input.
Example Lamp Expressions:
; Lamps Expressions
; analogue channel number, num lamps flasher up, num
lamps flasher down,
; flasher input name
*SS_LAMPS
=
L
2
2
2
FLASH_SY
*CS_LAMPS
=L
4
2
2
FLASH_CO
*SS_TIP
=L
3
1
0
STEADY
* CS_TIP =L 5 1 0 STEADY
7.1.2.11 Battery expression
A battery expression is used to configure the system with the battery
alarm voltage, a battery offset voltage, the analogue used to monitor the
battery test current, the battery test current in amps required for the
battery test, and the no battery test current threshold in amps.
There can be only one Battery expression for each level crossing. Battery
expressions have the following format:
x =B A B C D E
where
x is a internal variable which was declared in the IO list as a Battery. =B
identifies that it is a Battery expression.
A is the battery alarm voltage in volts. Typically this is set at 11.7 volts for a
flashing light level crossing, and 14.1 volts if booms are fitted. The voltage
is a real number and must be in the range of 7.0 to 18 volts. These alarm
voltages are set 0.5V less than the battery charger alarm card.
B is the battery offset voltage in volts. This is used to correct for the
voltage drop between the Level Crossing monitor and the Level Crossing
Bus. Typically this value is 0.16 volts. The voltage is a real number and
must be in the range of 0 to 0.5 volts.
C is the analogue channel used to monitor the battery test current. The
number must be in the range of 1 to 8. Typically channel 8 is used.
D is the required battery test current in amps. This is the current that must
be maintained through the battery test load for the duration of