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

2.8.3 DPX-224 Modem

For the Dataplex DPX-224 the following commands the following modem initialisation

string is required.

AT &F &C1 &D0 S0=2 Q1 E0 B0 X0 &W

The DPX-224 modem requires the serial port A to be set at 1200bps or 2400bps.

2.8.4 Maestro Executive 144FM Modem

For the Maestro Executive 144FM the following commands the following modem

initialisation string is required.

AT &F &C1 &D2 S0=2 Q1 E0 &K0 %C0 \N0 T L1 &W0

Serial port A is set for 9600bps to provide consistency.

This modem should not be used with normal level crossing monitor installations as it

normally operates from 240V AC. This modem uses a 240V AC - 9 VDC plugpack to

power the modem. This modem may be able to be used with a level crossing monitor

installation by operating the modem off the sensor supply or off the level crossing battery

supply using a regulator unit.

2.8.5 Modem Replacement

If the modem answers and you are unable to communicate with the monitor then turn the

modem off, wait 5 seconds and then turn it back on. The modem is reconfigured by

ensuring the modem is plugged into serial port A and resetting the level crossing monitor

(resetting the monitor by turning it off and back on OR by pushing the reset pushbutton

on the I/O card).

If turning the modem off then on and re-configuring it does not correct the fault then

replace the modem.

Turn the power off to the modem via the switch on the back of the modem or by

disconnecting the connector. Disconnect the power leads, unplug the telephone line and

the serial cable. Re-connect the new modem taking special care with the polarity of the

power leads positive and negative. The positive lead has a red strip running down the

length of the wire.

Turn the new modem on via the switch on the back of it or by inserting the connector. Re-

configure the modem by resetting the Level Crossing monitor (red push button in the

middle of the I/O Board). Watch the modem. The TX data LED should flash when it is

reconfigured.

The Dataplex DPX-223 modems are no longer available new from Dataplex. The

DPX-213 (10-20V DC version) should be used as a replacement.

2.8.6 Other Brand Modems

Modem designs are changing at a rapid pace. Manufacturers are designing new features

into their modem products which may not be compatible with existing monitor/modem

installations. Not all modems are the same and their can be problems with connecting

different brand modems especially on the poor phone line encountered in country areas.

Please contact Signal Engineering for advice on different modems and possible

replacement modems.

Maestro Jetstream Series 3, Uses a Lcent Chip Set.