Honeywell C300 User Manual page 232

8. C300 Redundancy operation
8.8. C300 Redundancy-related notifications
Notification
formally tested with redundant controllers prior to
distribution, marginal hardware is the most likely culprit.
Moreover, the full redundancy communication path has to be
considered:
In C300 Controllers:
Primary C300 -> Primary IOTA -> Private Path Cable ->
Secondary IOTA -> Secondary C300.
Sync Checksum Fail is detected by the secondary controller
which aborts synchronization and generates this alarm
notification. Detection of Sync Checksum Fail is severe in
that the redundant controller pair were allegedly
synchronized when redundancy tracked memory was found
to be different. In other words, switchover in the presence of
redundancy tracked memory differences may lead to bump
in control or loss of control (where the scope of the failure
varies on where and how the memory differed). Therefore,
by design, a Sync Checksum Fail occurrence disables auto
synchronization.
Hardware replacement is recommended upon Sync
Checksum Fail detection.
This notification returns to normal upon issuing the Enable
Sync or Alternate Sync commands.
Sync HW Failure Sync Hardware Failure is detected locally by the primary or
secondary controller which aborts synchronization and
generates this alarm notification. Detection of Sync
Hardware Failure is severe in that the redundant controller
pair could possibly repetitively synchronize and abort
synchronization continuously (unless 3 consecutive initial-
sync failures occur). Therefore, by design, a Sync Hardware
Failure occurrence disables auto synchronization.
Hardware replacement is recommended upon Sync
Hardware Failure detection.
This notification returns to normal upon issuing the Enable
Sync or Alternate Sync commands.
Standby Read description of
Upon entering the Standby state, this diagnostic alarm warns
users of the potential switchover to the CEE Idle
state. This notification returns to normal upon exiting the
Standby state either due to controller redundancy switchover
or the Disable Sync command.
Unexpected Partner Only the controller explicitly configured non-redundant
on Redundancy generates this alarm notification when a partner is present
222
Description
Standby state.
Series 8 C300 Controller User's Guide
Honeywell
RDNSYNCSTATE
PARTNERVISBL or
INCOMPATIBLE
R500
April 2017