question

Hello, i am looking to restrict the activity from moving an item from queue 3 to queue 5 conditioned on the queue 5 being empty. It will be best for me if i could implement this restriction on the processflow level. I could insert 2 triggers: one on entry to close the input port and one on exit to open the input port but i think my processflow would ignore theses triggers and continue to accumulate the items on queue 5 as long as there is no restriction on the sequence of tasks.

PFC.fsm