I tried to open the models what you prepared for Eugene, but unfortunatelly they were created in v14 Plant Simulation.
I have only v12 and one v13 Student version installed.
Could you please convert and insert them here, than I can study your solution for pullControl.
Converting from v14 to v13 or v12 means for me developing new in v13 or v12 !.
I think it will be a very good exercise for you to study and learn some more plant simulation basics
if you model the pull control yourself according to the posted 2 very well readable screen shots
( plus Plant Simulation P&P help)
If whilst development questions arise, the forum will give assistance.