Synchronize the Control System

In cases where the control system phase logic is reset or is run manually during a failure of the Batch Control system, it is possible for the two systems to disagree on a phase status when the Batch Control system is restarted. In most situations, the AVEVA Batch Management System is able to recover from such a failure. However, there are times when the AVEVA Batch Management System is unable to resolve the phase transition, or it is unsafe for the phase to be initiated.

The following table provides a summary of the possible states that could be experienced by a system shutdown. The rows refer to the current status of the phase in the control system following a shutdown and restart. The columns refer to the status of the phase in the batch control system following a shutdown and restart. Valid entries correspond to situations from which the AVEVA Batch Management System can recover. Re-Sync entries correspond to situations from which the AVEVA Batch Management System receives an unexpected status from the control system and must re-sync itself. In the re-sync cases, Batch Manager assumes the status of the control system phase status is correct and re-syncs with the control system and continues operation.

For example, suppose the AVEVA Batch Management System was controlling a phase that was previously in a status of Run. If the batch control system is shut down and the phase in the control system continues processing and becomes Done before the batch control system is restarted, the AVEVA Batch Management System recognizes this as a valid status transition, updates the status of the phase to Done, and initiates a phase Reset. However, if the control system is also shut down and the status of the phase becomes Ready, then Batch Manager assumes the control system and possible human intervention caused the phase to go to Ready. Batch Manager assumes the phase is done and continues on to the next phase.