Box size

Hi guys,
I am using cpu-416-2DP for moving different rectangular boxes over roller conveyors. I want to figure out the way of using some kind of sensor (laser) to determine the size of the box and the create even spacing in between them. We use constant speed for our conveyors. I was thinking to use my laser sensor to trigger the counter, and keep it counting in milliseconds until sensor is blocked( box passing by), then divide by max counter value (largest box) and use that value to tell next conveyor for how long to move, ultimately creating same spacing between different box sizes. Can somebody help me with this, or did somebody already done something similar. Thanks

How far away from the separation between the two conveyor belts is the sensor located? What sort of method are you using to stop the movement of the previous boxes on the line? If you hold the previous boxes while the first box moves away to create the desired gap, what happens when all the boxes backup and there is no longer a gap between them to measure?

I would put a photo eye sensor on the entrance of the second conveyor. As the first conveyor empties the part to the second, the eye is blocked, start moving the second conveyor. Once the eye is clear, keep moving it for X amount of time, what ever required to create the gap you want. This way you don't have to measure anything, your are creating the gap with a set amount of time and determining the position of the end of the box rather than the front.

Hi

I did something like this with a Wenglor Camera.

See also: http://www.plctalk.net/qanda/showthread.php?t=56548

If rising edge then SET a memorybit:
If memorybit then: New_Position = Previous_Position + (Speed * Last_Scan_Time)
If falling edge then RESET memorybit and tranfer New_Position to an other adress (record).

Regards,
Gerry

parni_valjak77 said:

Hi guys,
I am using cpu-416-2DP for moving different rectangular boxes over roller conveyors. I want to figure out the way of using some kind of sensor (laser) to determine the size of the box and the create even spacing in between them. We use constant speed for our conveyors. I was thinking to use my laser sensor to trigger the counter, and keep it counting in milliseconds until sensor is blocked( box passing by), then divide by max counter value (largest box) and use that value to tell next conveyor for how long to move, ultimately creating same spacing between different box sizes. Can somebody help me with this, or did somebody already done something similar. Thanks

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