Pieces on the Box [PickMaster 3]

Hello, we have 6 robot 340 irc5 whit 2 conveyors and PM 3.12.

We want to change the speed of the deposit conveyors (where we have a box whit 6 pieces) in function at the number of object that we have deposit in the box.

Where we can find the information for each robot of the number of product that remain to deposit in the box?

Thanks

Marco