Phase Logic

Phase logic refers to the steps and sequences in a control system that are exercised during the processing of a phase. Phase logic makes the control system program very structured. Phase logic is required to support every phase defined as automatic or semi-automatic. For example, if a process class of blenders has three automatic phases, each blender in the process class requires three phase logic blocks. Similarly, phase logic blocks are required for each automatic or semi-automatic phase defined for each connection assigned to a transfer class. The logic for each can be identical; however, the physical I/O and internal address assignments are different for each blender in the class. Manual phases are processed by the AVEVA Batch Management System through interaction with operators and do not require phase logic.

The following diagram shows the structured interface between phase logic and the AVEVA Batch Management System.