Compactlogix encoder tracking on conveyor Help needed

[kamenges]

I'm not clear on the tracking method you are currently trying to implement. There are two possibilities given the thinks being talked about so far.

The first possibility is you are maintaining a FIFO containing information on a specific package and it's status for every package in the field of concern. The other is that you are maintaining a "position map" that defines what is located in every distance increment in your field of concern. Which method you are using will change how you approach this.

Keith

 

[tmath820]

The thing i am concerned with is that the product sizes change. While slight, I am worried that there could be 3 of a smaller product during a run and then switch over to a larger product where there are only 2 of a product between the first and second cameras. So by inserting at bit 28 as Doug suggested makes sense to me. However, I think it would be a problem when the number of products change between the two cameras. If only two products then I would need to insert at bit 28 in a 30 long register. If three products I would need to insert at 27 in a 30 long register.

I thought by using the fifos by having two with fifos with fifo1 being 10 long and fifo2 being 3 long this would solve that as the first is the first in both fifos where as the BSL I could be a bit off.
Here is the layout.
Cameras 1 and 2 located at same trigger point. Turn on with encoder distance calculated of photo eye trigger.
Read camera result for pass(1) or fail(0)
Insert pass or fail (1 or 0) into BSL
When product gets to camera 3 do the same thing....trigger off encoder distance, read pass or fail and enter into BSL.
Then continue down the line to reject point and look at all registers to see if it should reject or not.

 

[osmanmom]

how the camera identify this is product-A and this product-B and so on?

 

[tmath820]

Camera gets a match code string to start. The result of the match code sets a bit to 1 pass or 0 fail. I then look at that to shift into the BSL.

 

[BlueAltezza]

I do this exact type of project on a fairly regular basis - and it was challenging to learn at first. There are many different ways to do it, so you'll have to experiment on what works best for you.

Instead of a bit shift for results/reject, you can load the encoder pulses/distance to the reject area into a fifo after the camera fails the product.