Two sets of proximity switches will be used to detect boxes passing by the sizing station.
Based on the size of the box that passes the station, the system will route the box to the corresponding palletizer.
The two sets of detection sensors help prevent unnecessary downtime should a box become skewed on the conveyor or a sensor fails.
Each box should be moving along the conveyor, so the inputs should return to false within a short period of time as the box clears the station.
If the proximity inputs do not reset after a short time, a box jam alarm will be indicated.
The lower proximity sensors are positioned to detect the smaller boxes near the top of the box.
The upper sensors are positioned to detect the larger boxes near the top of the larger boxes. The lower sensors will also sense the larger boxes, so we need to take that into account in the logic.