User's Manual

TRAIN CHIEF® II LRCS w/Lightweight OCU OWNER’S MANUAL
95-00-0-xxx Rev 000 7-7 Control Chief Corporation
SLC 500™ Error Conditions and Actions - CPU Major Fault
Power
Supply
Processor
POWER RUN
CPU
FLT
Error Cause Actions
ON OFF ON CPU Fault
CPU Memory Error Cycle power. If problem
reoccurs, contact factory.
ON OFF FL
CPU Major
Fault
Hardware / Software Major
Error Detected
(Erratic repetitive power cycling
can cause a processor major
hardware fault)
Cycle power. If problem
reoccurs, contact factory.
OFF= No Illumination ON=Continuous Illumination FL=Flashing
Control Chief Specific PLC Modules
High Current Relay Module with Watchdog
The primary function of this module is to monitor system operation and provide an active output
(by way of a dry contact closure) to indicate system status. The output is then used to control
the E-Stop relay which switches the application of primary power to the control system.
Operation
The High Current Relay Module with Watchdog monitors system operation by way of two built-in
watchdog circuits. The first watchdog monitors the SLC 500™ processor. When this watchdog
is satisfied it will enable relay output 0. The second monitors the ladder program. When the
second watchdog is satisfied it will enable relay output 1. The output 0 and 1 are hardwired in
series on the module (wired AND). The voltage source is wired to VAC-VCD WD IN. The high
side of the E-Stop relay is wired to VAC-VDC WD OUT. (For additional details refer to your
system prints.) The watchdogs are enabled once the OCU establishes a communication link
with the portable controller. If either one of the two watchdogs does not receive a timely refresh
it will time out which will turn off its associated relay output and disengage E-Stop relay resulting
in an immediate E-Stop.
The following error condition tables provide troubleshooting assistance for the High Current
Relay Module with Watchdog, including their potential cause, and recommended actions to
resolve the error condition.