Honeywell C300 User Manual page 214

7. C300 Controller Operation
7.14. C300 Controller processing overload behavior

Change the execution period and/or phase of some selected Control Modules in order
to more evenly distribute control processing across all control cycles in the two (2)
second control macro-cycle.

If the action above does not lessen control processing overload, then delete some of
the loaded control strategy. That is, inactivate and/or delete some number of Control
Modules (CMs). To perform this recovery process, first consider:

Which of the loaded CMs to delete from the C300 Controller in order to recover
from the overloaded state.

Prepare for the selective loss of control that will result as individual CMs are
placed in the Inactive state, and possibly deleted.
Then:

Begin by placing the least critical CMs in the Inactive state while monitoring
CPUFREE and the alarms that signaled the overload.

When the alarms indicating overload have 'returned-to-normal' and CPUFREE has
reached 5%, delete the CMs selected for deletion.
If a loss of view occurs due to non-control processing overload, then perform the
following actions:

Close displays requesting information from lost-view controller until view is restored.
If the loss of view is caused by an overload of display requests, it may be possible to
recover view by reducing the display request load to the controller.

If the C300 Controller is running as a redundant synchronized pair, Disable
Synchronization by clicking the 'Disable Synchronization' button on the secondary
C300 block properties form (if view exists to the secondary C300), or power off the
secondary controller. This will free up processor time that had been used to maintain
synchronization. The additional processor time may be sufficient to support
communication and view.

Shutdown controller and incrementally reload

Disconnect the battery from the affected C300 Controller.

Power cycle the unit.

Re-evaluate the size of the controller's planned configuration in light of the fact
that an extreme overload previously occurred.

Incrementally load and activate the configuration of the controller while paying
attention to CPU Free data and CPU Free Low and Low Low alarms.
206 Series 8 C300 Controller User's Guide
Honeywell
R500
April 2017