Phase Control

The batch control system transmits its phase requests to the control system through a series of tags that are mapped to the memory of the control system. One group of these requests is used to handle the phase control commands.

The control bits available for each phase are: Start, Hold, Restart, Abort, and Reset. Only the Start and Reset bits are required. When the batch control system needs to change the status of a phase block, it writes to a tag in the control system that corresponds to the particular phase control bit. These commands are typically packed into a word to maximize control system memory. In the phase logic, the phase control word can be monitored continuously or upon a change of status. Each of the commands is read as a one-shot action, and only one request is transmitted at a time. The particular control bits are used within the phase block, and the phase operation responds accordingly.