question

Varun Rawal avatar image
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Varun Rawal asked Regan Blackett edited

Photo eye to stop/resume a processer

I have a process spitting parts out at 333 part/min and an accumulating conveyor conveying those now I want to place a photo eye in the conveyor and when parts start back up on the conveyor and blocking the photo eye I want to stop my processes. SO should I trigger a signal to the process saying to stop on block? How can I do that.

FlexSim 18.1.1
processorblockedphotoeye
5 |100000

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1 Answer

Regan Blackett avatar image
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Regan Blackett answered Regan Blackett edited

Problems like this tend to be a little trickier than they seem on the surface; figuring out whether an item is blocking a Photoeye AND stopped on a conveyor, choosing good events that signal that the blocking item has moved on, etc. It can be done, but be prepared for things to not work quite how you intended the first couple of tries.

With that in mind, here's a simple example of one way you could approach it that involves process flow's Wait for Event capability.

Basically the model works like this: a photo eye is set down the conveyor and does NOT require a gap to clear, and I've set it up so that the Block Time is just a little longer than it takes an unobstructed flowitem to traverse the photoeye. In this case .31 seconds.

Then in Process flow I have a Source that creates one token at the start of the model and that token waits to hear the OnBlock trigger of the Photoeye. When the event takes place, I close Processor1's output ports (so it can send anything to the conveyor) and then wait for the item that blocked the photoeye to leave the conveyor. The token then reopens the output ports of the Processor and gets routed back to the Wait for Event that listens for OnBlock, and the cycle continues.


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