Specifications
RailCorp Engineering Manual — Signals — Equipment Manual
Cerberus Level Crossing Monitor Field Equipment Manual TMG E1261
© RailCorp Page 11 of 89
Issued August 2012 UNCONTROLLED WHEN PRINTED Version 2.1
1.6 Logging
Once every 0.25 seconds the Level Crossing monitor checks its analogue inputs, digital
inputs and its digital outputs for changes. If any changes are found then details of these
changes are logged with their date and time (to the tenth of second) of occurrence.
The log contains the last 8,000 changes. The oldest event is automatically replaced by
the next new event when the event log is full.
The log is maintained in a non volatile storage medium (battery backed memory). The log
is still retrievable after the Level Crossing monitor has been without power and
disconnected for at least 2 years.
Changes to the state of the flasher inputs are not logged. The VIOs used to monitor the
flasher units are connected to the level crossing monitor directly via the flasher cable (4
wires - 2 Red, 1 Blue, 1 Orange) to Input 4. This is solely to prevent wasting log space.
(See standard circuits in Appendix C)
1.7 Status Reporting
1.7.1 General
The Level Crossing monitor indicates its status locally using No Warning and or No Fault
indications on the front panel. If a warning or fault occurs, then the No Fault or No
Warning outputs turn off as appropriate and the cause is indicated by turning on either
system, lamp, battery, or logic output as appropriate. Details of the outputs are described
in the section on digital outputs.
Monitor status changes are reported to a pre-programmed phone number via a dial-up
modem if this facility is enabled. The message requires an acknowledgment. If not
acknowledged because the phone line is engaged or faulty the modem is hung-up and
the monitor will try again. The number of retries and the timing of retries are in
compliance with the ACA regulations for operating modems.
If present in the level crossing location when a monitor status change is being reported by
the level crossing monitor to a Control Centre you would see and hear the following
sequence:
• Hear dial-tone and red OH indication on the modem turn on as the monitor picks
up the phone.
• Hear tone or pulse dialling from the modem.
• Hear ring tone from the modem.
• Hear answer tones from the modem as the Control Centre answers its phone line.
• See the green CD indication on the modem turn on and the modem go quiet.
• See some seconds later the yellow TD and RD indications on the modem flash as
the message is sent and a return acknowledgment is received.
• See the green CD and red OH indications turn off as the monitor hangs-up the
phone.
1.7.2 Maintenance disable of Status Reporting
The maintainer may temporarily disable Status Reporting by holding the Fault Reset
button pressed for 5 seconds. The LOGIC led will flash once per second to indicate that
the monitor has had its reporting of status changes disabled temporarily. When in this
mode the monitor will not report changes of status to the Control Centre.
This mode is cancelled by a momentary push of the Fault Reset button or at pre-
programmed interval after activation. Normally this time-out is set at 45 minutes. All Fault