We have many recipes procedures written for one specific DeltaV Batch Unit Class. There are 14 instances of this unit class. For most of the recipes, any one of the 14 unit instances of the class can be bound to the recipe during batch recipe creation. There are a few recipe procedures that must limit the list of possible units to bind to show only 8 of the 14 units in that class. Only 8 of the 14 units in this class can produce this one product.
I have tried using Equipment trains, Unit Selection policy etc., but I cannot restrict the binding units list presented to the operator to display only those eight specific units. I have added a special Boolean Unit Parameter to the unit class named "PERMAX_CAPABLE" to act as a filter in the Unit Selection Policy: ['^/PERMAX_CAPABLE' = 'VYCAR_NO_YES:Yes'] When I use the Equipment Train class to restrict my unit selection to only the restricted units, the policy immediately binds the 'least used' or 'first available'. How can the automatic selection process be stopped, yet enforce the choice to a selected few units?