I am working on a model that uses process flow to stop items on a conveyor so they can be removed. There is some delay between stopping the item and removing it. Sometimes if the downstream items start moving again during the delay, the stopped item does too -- it seems like the accumulation restart is overriding my stop activity. How can I make it so that when I stop an item, it stays stopped until I tell it otherwise?
You can see it in the attached model. Watch the blue items at t=235 and t=255. (Items change color when they are stopped.)
(A little more info - the item is pushed to a list on arrival at a control point, and then removed from the list when the photoeye clears. The control points are in locations that correspond closely to the locations that items will accumulate. The list is used to find the box in the right location and pull it. Note that the needed stop locations aren't quite evenly spaced: there are groups of four, separated by some extra distance.)
