Configuring the phase logic
In DeltaV Batch, the phase logic is a state transition diagram made up of embedded composites that contain the logic that governs the transition between the states of a phase. The state transition logic is written using Sequential Function Charts. Also, the phase logic incorporates the use of phase logic parameters.
The phase logic you write contains the instructions to sequence the individual units to perform each state, such as opening a valve, starting a pump, or stopping a totalizer.
When using unit modules, the logic created at the phase class is inherited by the unit module. You can only edit the unit module's logic by opening the phase class. Phase logic modules do not inherit the phase class's algorithm. Instead, each phase logic module creates a new instance of logic that is independent of others in that class.
Once defined, the phase logic is downloaded to the controller. The recipe phase is connected to the phase logic through the unit class and phase class with which the phase is associated.
Caution is advised when downloading phase logic modules (PLM) when the PLM is currently active. The download leaves the PLM in the IDLE state and, when restarted, the recipe will run that phase again.
Recipes are defined in Recipe Studio to trigger the execution of the phase logic that resides in the process controller. The phase logic in the process controller contains the instructions to control the physical devices, such as a pump or a motor. The equipment required is defined on a phase (step) by phase (step) basis in DeltaV Explorer.