Specifications

RailCorp Engineering Manual — Signals — Equipment Manual

Cerberus Level Crossing Monitor Field Equipment Manual TMG E1261

Issued August 2012 UNCONTROLLED WHEN PRINTED Version 2.1

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_SYD

*CS_LAMPS =L 4 2 2 FLASH_COU

*SS_TIP =L 3 1 0 STEADY

*CS_TIP =L 5 1 0 STEADY

6.1.2.11 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 volts 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 volts 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 the battery test. Typically this is set at 6.0.

It is a real number and must be in the range of 5.0 to 20.

E is the value below which the battery test current in amps is checked to be whilst a

battery test is not being carried out. A value of 0 is not normally suitable due to problems

with the Analogue to Digital Converter used, and the Current Sensor used. Typically this

is set to 1.0 amps. It is a real number and must be in the range of 0 to 2.0.

Example of a Battery Expression: