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

• Looking at the mounting feet on the base of the Opto board, one side has a square

hole running along the length of the board with a lip that extends to be in line with

the side of the board. This side goes toward the 'thick' side of the Klippon rail. The

other end has a clip which extends diagonally out from the base of the board. The

notch at the end of this clip is inserted into the edge of the rail at 'thin' end of the

Klippon rail. Position this notch on the rail first then clip the board into place by

pushing the board at the thick side onto the rail. Check that board is correctly in

place by lightly tugging the board (Do not twist the board).

• Plug-in the D25F connectors. The D25M plug on the Cables is connected into its

corresponding D25F connector ( 'O/P1' or 'O/P2'). Screw the thumbscrew

fasteners in to place. Ensure that the screws are not so tight as to distort the

plastic hood of the D25M plug (finger tight is sufficient).

• Plug-in the 2 and 8 way connectors into their respective sockets.

2.6 Output Optoisolator

2.6.1 Description

The 8 Way Output Optoisolator Board ('Output Opto') is used to control the battery test

and operate no fault and no warning relays if required. They are called Optoisolator

Boards since the main components on the board which electrically isolates one side from

the other are Optoisolators. An optoisolator is a 'chip' that uses an internal LED which

emits light to switch a phototransistor on.

The main functions of the output optoisolator boards are:

• To isolate the main box from any possible power surges encountered on the level

crossing supply (1500V isolation).

• To convert the output voltage levels of the main box (0 VDC, +5 VDC) to DC

voltage levels suitable for operating relays such as QBCA1 and HH23-PW.

The Output Opto Board allows connection for up to 8 signalling outputs. Each output is a

voltage free contact that can drive nominally 120 mA (E.g. a Q-type relay ).

Dimensions are 100 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:

• 1 x 8 way ( Green ) connector and 1 x 2 way ( Green ) connector.

• Integrated circuits have a black coloured casing (National/Matsushita AQV214)

• Row of 8 indicating LEDs

• 1 x D15 Female connectors (labelled 'I/P 1' )

Refer to drawing M08-871 Layout., M08-872 Circuit, M08-873 cable.

2.6.2 Function

The Output Opto Board allows connection for up to 8 signalling outputs to be driven by

the Level Crossing Monitor. Each output is a voltage free contact that can drive nominally

120 mA DC (e.g. two Q-type relay or 5 LEDs). The Output Opto Board is protected

against back EMF and is suitable for driving relays directly without any additional

protection.

2.6.3 Operation

The level crossing monitor drives circuits 1 to 8 respectively through pins 1 to 8 of the

D15F connector. All 8 circuits are identical and have consecutive component numbering.