Hard/Severe Failures - Honeywell C300 User Manual

Fault Classification
Soft Failure
Installation/Startup
Failure
Communications
Failure

Hard/Severe Failures

When a hard failure is detected, the following controller events occur depending on its
redundancy status:

Hard/Severe failure on a synchronized primary controller triggers a switchover to the
backup controller. The I/O modules associated with the controller force their outputs
to safe values. If capable, the failed controller reboots into the FAIL state and
captures diagnostic data which may contain internal state events that occurred prior to
a failure. The Ctools utility can be used to retrieve the diagnostic data.

Hard/Severe failure on a backup controller causes a loss-of-synchronization. The
Primary controller continues operation, but enters the 'Not synchronized' state. If the
redundant controller pair was not synchronized when the fault occurred, then the
failed controller reboots into the FAIL state, if capable. No further synchronization
will occur and no switchover occurs.
R500
April 2017
Software detected failure. Controller continues to operate with full
control and full view. Soft failures are alarmed to the operator. FTE is
monitored by the FTE System Management Tool.

Soft failure on the synchronized primary controller does not
trigger a switchover to the backup controller.

Soft failure on the backup controller does not result in a loss-of-
synchronization.

Soft failure on a non-redundant controller does not result in loss-
of-control or loss-of-view.
Software detected failure. Controller may not become operational.

Installation/Startup failure on a non-redundant controller results in
the inability to commence control or view the controller on the
network.

Installation/Startup failure on the backup controller results in the
inability to complete initial synchronization or view the controller
on the network.

Installation/Startup failure does not apply to the synchronized
primary controller, because installation and startup must be
successful to reach a synchronized primary state.
Communication errors between peer controllers, nodes and/or I/O
devices - do not cause any controller state change.
Series 8 C300 Controller User's Guide
Honeywell
10. C300 Controller Troubleshooting
10.9. Fault classifications
Description
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