Fault Finding And Maintenance; Fault Reporting; Field Wiring Faults; Module Faults - Rockwell Automation ICSTT-RM280N-EN-P Manual

Trusted TMR 24Vdc Digital Output Module – 40 Channel

5. Fault Finding and Maintenance

5. Fault Finding and Maintenance

5.1. Fault Reporting

Output Module faults are reported to the user through visual indicators on the Front Panel
of the Module and through status variables which may be automatically monitored in the
application programs and external system communications interfaces. There are generally
two types of faults that must be remedied by the user: external wiring and Module faults.
External wiring faults require corrective action in the field to repair the fault condition.
Module faults require replacement of the Output Module.

5.2. Field Wiring Faults

By measuring the output channel voltage and current, the Module automatically detects
field wiring and load faults. When a field signal fails open circuit, short circuit or there is no
field supply voltage connected, the output status indicator will display the configured LED
mode, the corresponding output state will be reported and the line fault status for that
channel will be set to '1'. All other output channels will be unaffected, except in the case of
common cause wiring and supply voltage faults in the field.
The field output voltage and current variables can be monitored to determine the actual
operating conditions of each output channel. This additional information assists the user in
determining the specific type of wiring fault.
Once the specific field wiring fault has been identified and corrected, the output status
variables and output status indicator will display the normal on/off status of the field device.

5.3. Module Faults

Extensive diagnostics provide the automatic detection of Module faults. The TMR
architecture of the Output Module and the diagnostics performed verify the validity of all
critical circuits. Using the TMR architecture provides a Fault Tolerant method to withstand
the first fault occurrence on the Module and continue normal output controls without
interruption in the system or process. Faults are reported to the user through the Healthy
status indicators on the Front Panel of the Module and through the INFO and HKEEPING
variables. Under normal operations all three Healthy Indicators are green. When a fault
occurs, one of the Healthy Indicators will be flashing red. It is recommended that this
condition is investigated and if the fault is within the Module, it should be replaced.
Module replacement activities depend on the type of spare Module configuration chosen
when the system was configured and installed. The Module may be configured with a
Dedicated Standby Slot or with a SmartSlot for a spare replacement Module.
Rockwell Automation Publication ICSTT-RM280N-EN-P Issue 14 29