38 Rockwell Automation Publication ICSTT-RM406J-EN-P - February 2021
Chapter 4 About Troubleshooting
channel fault and a module fault. This means that the Channel status indicator
will show red, the Healthy status indicator of the I/O module will show red and
the System Healthy status indicator on each processor module will also show
red.
It is possible during sustained periods of abnormal field voltage and/or
current slewing for channels to be declared faulted as a consequence of
diagnostics otherwise designed to verify that the channels are operating
within their designed safety accuracy. For details of slew rate limitations, refer
to the AADvance Controller Solutions Handbook, publication ICSTT-RM447
.
Field Fault
The controller indicates a field fault when it detects a fault and can isolate it to
a field condition or a field device. Examples are an open circuit field
connection or an out-of-range signal. The Channel status indicator on the
applicable I/O module will go Amber.
I/O Module Channel
Degradation and Shutdown
Input Module Non-degraded Status
Degradation for input modules is on a channel-by-channel basis. A channel is
considered not degraded when all the modules in a group are on-line and none
of them are reporting a fault for the specified channel. For each I/O module
channel, the AADvance Workbench software or AADvance-Trusted SIS
Workstation software reports the module status variable Discrepancy as
FALSE.
• A simplex module configuration that has not degraded reports the
channel values to the application.
• A dual module configuration that has not degraded reports the channel
values to the application.
• A triple module configuration that has not degraded reports the values
from any of the three channels in the group.
Input Module Degraded Status
A channel is considered fully degraded when no modules in a group are
reporting values for that channel, or there is a fault reported on that channel
for all modules in the group, and either condition exists for longer than the
PST. For each I/O module channel, the AADvance Workbench software or
AADvance-Trusted SIS Workstation software reports the module status
variable Discrepancy as TRUE and the module reports 'safe' values back to the
application for the faulty channel.
Degraded Channel Reporting Values
When a fault exists on a channel, the module will report safe values for that
channel and the Discrepancy status variable reports TRUE.
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