Equipment Control is generally programmed in an equipment controller - ie the controller that is directly connected via Inputs and Outputs to the equipment.
Most of this control will be Basic Control but there must also be some Procedural Control, normally either Phases or Operations.
These Phases or Operations. Can be programmed using sequential logic, typically using SFC's, again this is programmed in the equipment controller
One Key point is that these have a Start, which normally comes from Recipe Management, and an End, which should naturally occur when the phase or operation completes it's task.
When designing such Phases some points should be considered
Assume that the Recipe Manager will fail - if this should happen, the current phase will still complete but the next one will not be initiated. In this case the phase should leave the process in a stable state. This is because many batch process can tolerate being left in certain states for some time.
So for example a filling phase should terminate After closing the fill valve