To test the box jam logic and stack lights, we will set the value of N7:2 to 3 so that the program will temporarily end after the box jam alarm and stack light logic. We inspect the TND instruction in Rung 10 to see where the logic processing will end.
The “Temporary End” instruction behaves much like the “Suspend” instructions, except processing does not suspend, but continues again at the beginning of the program with Rung 0.
This is one reason we had placed the “Jump to Subroutine” at the beginning of the program. Now, when we test the alarm conditions, we can see the effect it will have on the conveyor motors.
We have isolated the FIFO logic, which will not execute during this series of tests. But because the logic is executing normally otherwise, when we set a sensor on at the box-sizing station and do not reset it, the jam timer will time out and cause a Process Stop.