Specifications

Engineering Standard –NSW
Signalling SMS 02
Cerberus Level Crossing Monitor Equipment
March 2005 Version 1.2 © Australian Rail Track Corporation Page 37 of 118
This document is uncontrolled when printed.
level crossing monitor). When the level crossing lamps are off the
voltage across 3, and 4 should be 5 volts. When the lights are flashing the
voltage across 3, and 4 should vary between 1 volt and 5 volts in
sequence with the flashing lamps.
If either of these cases is not correct then replace the unit.
Note: Terminals 1, and 3 should always be more positive than terminals
2 and 4.
3.4.6 3.4.6 Replacement
Disconnect the wiring from terminals 1 to 4. The wires connected to
terminals 1 & 2 are connected to vital signalling circuits and the
appropriate procedures must be followed for modifications to vital
signalling circuits. Make sure these wires are identified and will not be
shorted out. Unclip the VIO from the Klippon rail. Clip the replacement to
the Klippon rail. Terminate the wiring back on to terminals 1 to 4.
Ensure that the replacement unit is
same voltage as the unit being
replaced. Ensure that a 12V VIO is
not being used on 50 volt Vital
Signalling Circuit.
3.5 Input Optoisolator
3.5.1 Description
S-2000 D12/2.0 IIO. Dimensions are 315 mm (l) x 76 mm (w). The PCB
is held in a green plastic circuit board module with mounting feet which
clip on to TS32 (Klippon) rail or TS35 (DIN) rail. Identifying features of
the board are:
(a)4 x 8 way ( Green ) connectors (b)2 x 2 way ( Green ) connectors
(c)Integrated circuits have a white coloured casing (4N35)
(d)Row of 32 indicating LEDs
(e)2 x D25 female connectors (labelled 'O/P 1' and 'O/P 2')
Refer to Drawing M08-731 for physical aspects, drawing M08-732 for the
schematic diagram of the input optoisolator, drawing M08-733 for circuit
diagram of the input optoisolator.
Refer to drawing M08-782 for an example of the input optoisolator circuit
in operation.
CAUTION