how to use c1Rem1PObj for conveyor tracking

ssu_8421

the question is like this:

I am in a project which use conveyor tracking to pick products transfered from a conveyor.

Now, i want the robot to pick one product and then let the next one pass (can not use the sync distance, i need to know exactly that one produt is passed).

My plan is to use the c1ObjectsInQ and c1Rem1PObj to realize it. After the robot get one product, when the new object enter the queue, use the c1Rem1PObj to remove it.

But i find it i can only get the value of c1ObjectsInQ when c1PosInQ is 0.

How can i use the function or how can i get the result of pick one product and let the next one pass.