Stop product on conveyor

Hello All,

I am trying to model an assembly line conveyor where the product stops at a work station for a given amount of time. After this time the product is then moved by the conveyor to the next station. There are 6 stations on one conveyor line. How do i model the boxes stopping on the line so the operators can work on them.

I was thinking I would use photo eyes to stop the product but i couldn't figure out how to use the code to do it. Right now all i have is 6 photo eyes spread out 10 ft apart on a 60 ft conveyor. Thanks.

Derrick

Derrick,

First, could you update your profile about me section so that the rest of us can get to know you better. I know that for me it helps to motivate me to give better help.

Now to the help,
If each station conveys product seperately then you could do the following:

1. Creat a conveyor for each process (Meaning that the end of the conveyor is at the processng point).
2. On Convey End. Close the output and send a delayed message (time = processing time).
3. On message open the output port of the conveyor.

This should produce what you want with the added benefit of being able to write as little code as possible on one conveyor and then copying that code to the others. Also, if there is a gap in the product or any bottle necks down stream, then this should simulate that correctly.

You could put a processor at the end of the conveyor but then you would have to write additional code to stop the conveyor and such.

If you are trying to simulate one conveyor that stops when a product is in front of the operators for x seconds and then starts up again to move to the next station then try this:

1. You will use one non-accumulating conveyor that ends just after (distance past the last station must be > 0 but < distance between stations) the last processing step and begins the same distance in front of the first station that exists between all the other stations.
2. On Entry send a delayed message of Type 1 (time = distance / speed)
3. On Message Type 1, if content > 0 then stop conveyor and send another delayed message of Type 2 (time = process time). Now you will go to 4 or exit the loop.
4. On Message Type 2 resume conveyor and send a delayed message of Type 1 (time = distance / speed). Now you will go back to step 3.

This should give you an answer that has a limited amount of code.

In both cases if you want to track the states you could do this by putting a photo eye at each station that when covered would change the state on a dummy processing station obejct to STATE_PROCESSING and when uncovered would change it back to STATE_IDLE.

Good Luck,
Brandon

I tried the first method using the stop output and delayed message. When the flowitem gets to the end of the conveyor it stops like it should but the model run time stops as well. I have it set up for the Onconveyend code there are both the close output using the close open port tab and also send a delayed message. On the onMessage line i have openoutput. Do you have any idea why it would stop the whole model and not just the flowitem for the delayed time?

I was able to get the model time to last as long as the time to convey to the end plus the delay message time. So it takes 5 sec to convey and i have the delay set for 10 meaning it quits after 15 sec. It must have something to do with the Onmessage releasing the flowitem. In the onmessage code block i changed it from closeinput to openoutput. I'm not sure if this is the problem.

If someone could throw a small model together showing the code and the connections needed I would appreciate it. Thanks.

Derrick

Derrick,

Thanks for filling out the about me section!

Here is a model that shows the first method I explained.

Good Luck,
Brandon