Specifications

Engineering Standard –NSW
Signalling SMS 02
Cerberus Level Crossing Monitor Equipment
March 2005 Version 1.2 © Australian Rail Track Corporation Page 45 of 118
This document is uncontrolled when printed.
If the output is OFF when it should be ON and the LED is
illuminated
The fault exists in the Output Opto Board or the signalling system.
Check in the following order until the problem is rectified
Check that power is being switched to the output device (i.e. check
for blown lamp or fuse etc.).
Check that the supply side of the contact has power if a positive
switch wire (on '+' terminal)
Replace Output Opto Board.
The Output Opto board can be double checked by removing the
orange 8 way connector. Place an Ohmmeter across the '+' and '-'
terminals. If the reading is less than 15 Ohms, then the circuit is OK.
If the reading is a open circuit then the circuit is faulty, therefore
replace board (or you can try just replacing the AQV214H but
ensure the orientation is correct).
Replace the individual Optoisolator IC or the complete Output Opto
Board.
The Output Opto board can be double checked by removing the
orange 8 way connector. Place an Ohmmeter across the '+' and '-'
terminals. If the reading is less than 15 Ohms, then the circuit is OK.
If the reading is a open circuit then the circuit is faulty, therefore
replace board (or you can try just replacing the Opto Isolator chip
AQV214H but ensure the orientation is correct).
If the output is OFF when it should be ON and the LED is
extinguished
The fault is unlikely to be in the Output Opto Board. Check in the
following order until the problem is rectified:
Double check inputs associated with this output. The output may be
behaving correctly, but there may be a faulty input giving the
system the wrong information.
Check I/O Cable connections.
Check I/O Cable for damage.
Replace the main box.
The output is ON when it should be OFF and the LED is lit
The fault is unlikely to be in the Output Opto Board. Check in the
following order until the problem is rectified:
Double check inputs associated with this output. The output may be
behaving correctly, but there may be a faulty input giving the
system the wrong information.