Slug conveyor pre-staging for merge controller

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Craig DIckson asked Nov 21, '19 Ben Wilson commented Dec 18, '19

Slug conveyor pre-staging for merge controller

I have several non-accumulating slug conveyors that feed in to a merge. (I will either use a merge controller or the fixed-gap process flow posted in 2016 by @anthony.johnson (Article name "Process Flows for Two Types of Merge Controller"). The only difference is I (or rather our controls engineer) want the slug to advance to the head of the conveyor once it it built, so that it is closer to the merge when it is released. In other words, once the conveyor gets to (e.g.) 85% full, it stops accepting new cartons and moves all the cartons on it forward for the remaining 15%, so that the first carton is at the discharge end of the conveyor, before the slug is considered ready for release.

Software Version:

FlexSim 19.2.4

slug conveyors merge logic

· 4

tannerp commented · Nov 22, 2019 at 10:07 PM

Hi @Craig DIckson,

Unless I'm misunderstanding something, the first carton would already be at the front of the conveyor when the slug is discharged. This is because there wouldn't be anything telling the slug to build up in the middle of the conveyor. Or maybe I'm just misunderstanding where you want the items to be held. If you had multiple conveyors, you could release the first one (a slug conveyor) and then stop the slug at a DP on the next conveyor until it's ready to be released.

Maybe you could post an image or something that would help us visualize the process?

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Craig DIckson tannerp commented · Nov 25, 2019 at 07:57 PM

The actual slugging conveyor is a bit longer than the typical slug being built (80%), so the head carton is back some distance. (Remember this is on-accumulating slug conveyor.) But I want that head carton to index to the front before the slug is released into the merge. (Also the head carton could be back even further if a slug times out, or if we used item count to define the slug and happened to have a higher than average number of smaller cartons.

Note - for some reason I can't seem to attach the jpg graphically describing what I want?

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Craig DIckson tannerp commented · Nov 25, 2019 at 07:58 PM

@Tanner.p I got the sketch to upload. Looks like forums was down when I first tried? staging-slug-non-accumulating.jpg

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staging-slug-non-accumulating.jpg (57.3 KiB)

Ben Wilson ♦♦ commented · Dec 18, 2019 at 09:02 PM

Hi @Craig DIckson,

Just following up on some dormant questions here on the site. It looks like @Braydn T and @tanner.p had some suggestions/questions for you. If you've already solved your problem, great! If you are still looking for some answers, please comment back to let us know where you are with this and how we can help.

Or if Braydn's suggestion solved if for you, go ahead and hit the Accept link on his answer.

Thanks!

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Answer 1 · 2019-12-12T18:05:43Z

Braydn T answered Dec 12, '19

@Craig DIckson

I am a little confused about what exactly you are asking here, but I would use a typical merge controller with a lot of decision points sending messages to each other in triggers. You will have a decision point at the 80% mark and hold until a photo eye is covered. when the photo eye is covered it will allow flow items to pass the first decision point, and not allow any more flow items onto the staging lane. You will just use the merge controller with the decision point that is right before the merge lane, and with the points on the merge lane. Does that make sense? Is that what you were asking? If not, please let us know!

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