I am working on programming my cell. It consists of 4 load nests that allow me to stack 100 pieces in each stack. There is a prox switch at the bottom of each stack used for part present. I am trying to use the Seek/Destacking function to pick parts one by one. I load up all stations and press start. Robot unloads first station, no problem and starts unloading second. In the meantime, I place more parts in the first nest. The robot now returns to unloading the first nest before completely unloading the nest it was working on. I am using an If statement related to the part present sensors and calling a subprogram that has the destacking info in it. How can I get it to complete the stack it is working on without moving to another stack?