Phase failures

Phase failures occur for a multitude of reasons. Simple phase failure occurs when an operator attempts to connect to a procedure that is not idle, or when an operator attempts to run a phase that is owned externally.

Failure to load phase errors generally are the result of (but not limited to) the following:

• The unit being out of non-reserved slots (adjust MAX_RESERVED parameter)

• The controller being out of memory

• The phase class name being incorrect

• The phase being disabled on the unit module

• The unit module being out of service

When a phase failure occurs, an alarm is displayed in the Alarm Summary screen. These phase failures are defined in the failure register of the process controller and are sent when a phase fails to function properly. For example, when a phase programmed to open a valve fails and the valve remains closed, the phase failure is sent.

A unit phase can fail to be instantiated if the controller does not have enough memory when the phase is run either by the operation or manually by the operator. This will cause a phase failure and, depending on the hold propagation defined on the Batch Executive Properties dialog, can cause the higher recipe levels to hold.