8. C300 Redundancy operation
8.5. Redundancy parameters
214
Series 8 C300 Controller User's Guide
Honeywell
R500
April 2017
Secondary module recovery from dual-FTE-cable disconnect.
Secondary module powerup.
Secondary module reboot into Backup state following firmware update.
Secondary module reboot into Backup state following recovery from the Fail state.
Auto synchronization retries
Once the Auto Sync State is enabled, loss of synchronization is automatically followed by
an automatic attempt to re-synchronize the redundant controller pair. However, after a
maximum of 3 initial-sync failures, the Auto Sync State is disabled with an inhibit sync
reason of Initial Sync Fail.
Inhibit Sync Reason - RDNINHIBITSYNC
Whenever the C300 is not in the synchronized/standby states and initial-sync is not in
progress, the RDNINHIBITSYNC parameter is set to the inhibit sync reason. Reasons
for inhibiting initial-sync include the following:
Inhibit Sync Reason
Description
Startup In Progress
Initial sync is not allowed until after the C300 has completed system
startup. This is a transient inhibit sync reason that is usually not
seen.
Auto Sync State
Initial sync is inhibited while the Auto Sync State is set to disabled.
This is a persistent inhibit sync reason that is canceled through the
Enable Sync command.
Dropping Sync
Initial-sync cannot commence until the previous abort sync
operation has been completed. This is a transient inhibit sync
reason that is usually not seen.
Initial Sync Delay
There is a guaranteed 20 second delay in between initial-sync
attempts. More specifically, for 20 seconds after a compatible
partner is identified, initial-sync is inhibited with this transient
reason.
Initial Sync Fail
After 3 failed attempts to perform initial-sync, the Auto Sync State is
automatically set to disabled and the inhibit sync reason is set to
this persistent value. Refer to the redundancy history for the
reasons why initial-sync failed, and issue the Enable Sync
command to attempt initial-sync again.
Redundancy
Configuration State
Initial-sync is not allowed when explicitly configured as non-
redundant. This persistent inhibit sync reason can only be canceled
by reconfiguring the non-redundant C300 FB as redundant.