Phase Status

The batch control system recognizes the current status of a phase block through a series of tags that are mapped to the memory of the control system. One group of these requests is for monitoring the status of each phase. The status bits available for each phase are: Ready, Run, Held, Done, Interlocked, and Aborted. Only the Ready and Done bits are required.

When the phase block status changes, either through the phase logic or from a request from the Batch Management System, the phase status word is set accordingly. In the phase block, the phase status word can be continuously written or written only when the status changes. When a phase status changes in the control system, the bit associated with that status in the phase status word is altered. All phase status changes must be transmitted to the Batch Management System through the phase status word. The phase block can be in only one state at a time.

The following conceptual diagram shows available phase status bits.