About the model of reversible conveyor

Question

question

tomonori S asked Aug 02 2021 at 8:52 AM Ryan Clark edited Sep 09 2021 at 9:58 PM

About the model of reversible conveyor

The user has a question about the attached model.

Currently, we are ranking flow items, but I would like to bring them to the sink in this order, so please tell me how to make them.

The processing time at the station varies depending on the product, so even if the processing of the products that arrived later is completed, I would like to stay on the spot (station) and execute it after processing the products that arrived earlier.

I created a process flow as a trial and set it to flow only rank 1 items, but it seems that stopping and resuming custom code is not working well.

model_01.fsm

Software Version:

FlexSim 21.0.3

wait for event custom code decide station reversible conveyor

model-01.fsm (57.6 KiB)

· 1

______

Cookie preferences

Your privacy is important to us and so is an optimal experience. To help us customize information and build applications, we collect data about your use of this site.

May we collect and use your data?

Learn more about the Third Party Services we use and our Privacy Statement.

Strictly necessary – required for our site to work and to provide services to you

These cookies allow us to record your preferences or login information, respond to your requests or fulfill items in your shopping cart.

YES

Improve your experience – allows us to show you what is relevant to you

These cookies enable us to provide enhanced functionality and personalization. They may be set by us or by third party providers whose services we use to deliver information and experiences tailored to you. If you do not allow these cookies, some or all of these services may not be available for you.

YES

NO

Customize your advertising – permits us to offer targeted advertising to you

These cookies collect data about you based on your activities and interests in order to show you relevant ads and to track effectiveness. By collecting this data, the ads you see will be more tailored to your interests. If you do not allow these cookies, you will experience less targeted advertising.

YES

NO

Are you sure you want a less customized experience?

We can access your data only if you select "yes" for the categories on the previous screen. This lets us tailor our marketing so that it's more relevant for you. You can change your settings at any time by visiting our privacy statement

Your experience. Your choice.

We care about your privacy. The data we collect helps us understand how you use our products, what information you might be interested in, and what we can improve to make your engagement with Autodesk more rewarding.

May we collect and use your data to tailor your experience?

Explore the benefits of a customized experience by managing your privacy settings for this site or visit our Privacy Statement to learn more about your options.

Answer 1 · 2021-08-02T10:28:12Z

Felix Möhlmann answered Aug 02 2021 at 10:28 AM Ryan Clark edited Sep 09 2021 at 9:58 PM

1. It seems that when you reverse the conveyor, the items get processed again by the station. I added the condition that only items with "Flag != 1" should be processed, so this doesn't happen.

2. One important thing to note here is: If you "stop" an item X times, you also have to "resume" it X times before it actually continues. In your model items might get stopped multiple times, because the tokens react to any station finishing its process, than stop the item and only continue it, when it has the correct rank.

I changed this so the item gets stopped in the arrival trigger of the station. The Wait for Event activity in the process flow now waits for the item it is assigned to to finish the process. It then either resumes the item if the rank is correct, or sends it to another Wait for Event. There it waits until another item has left the system (passed DP8) and then tries again.

3. To know which item's turn it is, I created a global variable "CurrentRank". This is an array with as many entries as there are item types. Each entry starts at 1. The process flow checks whether the items rank is equal to the value of "CurrentRank" at the index of the item's type. If that is the case, the items rank is the next one in order and it can continue. Each time an item passes over DP8, the arrival trigger increments the value of that types entry in the array by 1.

The "Breathe" delays in the process flow are important. They make sure, that the update of the global variable, item label and conveyor speed are complete before accessing these values.

model-01_fm.fsm

I hope this is helpful to you.

model-01-fm.fsm (58.9 KiB)

· 6

tomonori S commented · Aug 03 2021 at 5:58 AM

Thank you for your polite reply.

I have additional questions about this model.

In the attached model, on the source side of the 3D model, flow items are ranked in order of generation, regardless of type.

Please tell me how to flow flow items in rank order in such a situation.

model_02.fsm

0 ·

model-02.fsm (54.9 KiB)

Felix Möhlmann tomonori S commented · Aug 03 2021 at 9:46 AM

Change the global variable "CurrentRank" into an integer instead of an array. Then, in the decide activity and the code snippet of the arrival trigger of DP8 just use "CurrentRank" instead of "CurrentRank[item.Type]".

That way, the rank is not split by type but combined for all items.

model-02_combinedRank.fsm

0 ·

model-02-combinedrank.fsm (55.1 KiB)

tomonori S Felix Möhlmann commented · Aug 11 2021 at 7:55 AM

Thank you for your support.

0 ·

tomonori S commented · Sep 06 2021 at 1:41 PM

excuse me. It's been a while since the previous question, but when I change the process time of each station in the attached model, the flow items do not flow in the order of rank.

What is the cause of this?

model-03.fsm

0 ·

img.png (10.1 KiB)

model-03.fsm (54.4 KiB)

Felix Möhlmann tomonori S commented · Sep 06 2021 at 2:56 PM

Setting the conveyor speed to a negative value seems to overwrite the "stop" of the item. This wasn't apparent last time because mostly the items will trigger the station again when the direction is reversed, thus renewing the "stop" of the arrival trigger. Mostly, but not always. In cases where the event doesn't trigger a second time the items simply continue with the tokens still stuck in the process flow.

I could fix this by connecting the conveyors to motors and stopping and resuming those instead.

model-03_motors.fsm

0 ·

model-03-motors.fsm (56.9 KiB)

tomonori S commented · Sep 07 2021 at 3:54 PM

@Felix Möhlmann,

Thank you for your reply.

I have a question about the model. Please tell me the meaning of the part surrounded by red in "img_01.png". Also, how does connector 2 used in this "Decide" work?

0 ·

img-01.png (52.2 KiB)

question