In your first custom code activity you check the content of "Zone" (which doesn't exist) instead of "Zone2". As such the input never actually closes.
How to control the work stations depends on what exact logic you want to achieve, as there are numerous possible options.
1) Close the input: Prevents work stations to start on a new item but current items will be finished.
2) Close output/input of conveyor transfer: Further items are finished but not released to the conveyor until there is space.
3) Stop objects: Work on the current item (if there is one) is halted. No items can enter or leave the work stations.
In the attached model I demonstrate option 3, stopping the stations and operator animations in custom code activities depending on the zone content.
waiting-conveyor-processor-fm.fsm
