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Parallel Unit Procedures - Avoiding Stop logic?

Hey all, looking for some input on a Batch recipe issue I am looking at. We have had arbitration issues in the past with holding up our primary vessel while waiting for a charge to complete on a secondary vessel (precharge of another raw material). In order to work around this, I was trying to set up a recipe with a trigger to start a new unit procedure on the secondary vessel, that way there is no unit procedure that is sharing UP. The primary vessel can finish its UP, and the secondary vessel can start the next UP. Recipe studio allows me to do this, and it works, but during the transitory period both phases will run their stop logic. Is there any way to make this transition seamless or do I need to deal with the stop logic? 

See snip below, UP_TEST is the primary vessel and UP_FINISH is the secondary vessel.

3 Replies

  • Do transition T2 checks for default code both unit procedure completed?

    Please check options 'Acquire unit prior to starting unit procedure?' and 'Retain unit after completing unit procedure?' on UP steps in procedure can handle unit arbitration issue.
  • In reply to vmvmhatre:

    T2 would check if UP_TEST:2 is complete, and allow UP_FINISH:1 to move to UP_FINISH:3.

    The problem is when making that transition, the phase currently loaded on UP_FINISH:1 stops while switching to UP_FINISH:3. I would like this to be seamless if possible. The same occurs when moving from UP_TEST:1 to UP_TEST:2. I want the operator to answer a prompt, and move into the parallel procedures without the batch stopping.

    Would acquire unit and retain accomplish this? I can try it, I'm trying to walk through it. Does UP_TEST:1 complete when it moves to UP_TEST:2, even though they are a continuation of the same UP?
  • There is an alternative but it will be more complex that current behavior you have, assuming STOP will be launched and implement it as required to make this work.

    The alternative is using continuance and UP to UP data exchange through REFERRED/DEFERRED report parameters.
    However, continuance can be used only at the OPERATION between PHASE STEPS, level so basically you will need to reconfigure you recipes completely.

    Perhaps it is better to keep what you have and implement STOP as nneded.