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PeterHe avatar image
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PeterHe asked Jeanette F commented

About the Conveyor and Decide



Question1:How do i get the pallet to stop on the green point?

Question2:When the all green point has the pallets.how to pallet selection red point line body output? how to program for decide point?

PF Tutorial 1 DIY Error.fsm

FlexSim 22.0.0
conveyorsystemconditional decidebuffer
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1 Answer

Jason Lightfoot avatar image
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Jason Lightfoot answered Jeanette F commented

First of all you have exceptions. The system console is telling you helpful information about the state of your model so it's important that you pay heed to the messages it's giving.

At reset :

MODEL:/Queue1>variables/sendtoport Line 7        Undefined variable boxpallet being used.

which is caused by this expression:

boxpallet.Type == 1

The triggering item will be passed in as item so use that, not 'boxpallet'.

Then you have a similar error at reset in the process flow where you assign event object to 'matchpallet'. The syntax for this needs to be token.matchpallet. Yes, it's inconsistent with other fields where you just supply the label name.

Next You have a problem that boxpallet doesn't exist on the Decide in the process flow. That's because you reference 'boxpallet' in the decision condition but have set the label to just 'pallet' in the source. You're testing ==0 so maybe you're looking for a label on the pallet called 'boxpallet' in which case the syntax would be token.pallet.boxpallet?==1. I put the question mark in there because I don't know if you intend to have the label always present


With those fixed we can start considering what you want to happen.

Are you saying you want to have a pallet at each green decision point before some process can start? If so you can use an ordered list of the DPs (use a Group or label array) to pull in sequence and label and route the pallet to each. Or you can use port connections to send to the green DPs in a round robin sequence, making sure the port sequence is the furthest on port 1.

Then you need to detect the arrivals of the correct pallet at each DP which could be done using an event triggered source.

To stop the pallet use a custom code from which you can select the predefined template to control conveyor movements including stopping/resuming the item.

If however you're just using the DPs to seperate the pallets which are accumating before an operator station at DP2, then you don't need the DPs to do that - you can just change the accumulation properties of the conveyors so that they have the correct gap.

You questions title suggests this is first process flow tutorial but it seems that's not the case.

Here's the model with errors fixed.

pf-tutorial-1-diy-error_jl.fsm


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PeterHe avatar image PeterHe commented ·

buffer-full-change-to-redpoint-output.jpg

I have two questions:

Question 1:How can PF be programmed to take the red point path in this state,release empty pallet. I tried "on Item Bump" to listen for the conveyor, but the Pull token failed .

empty-to-sink1-box-to-sink2.jpg

Question 2:How can PF be programmed to take the empty pallet to sink1 and pallet with boxes to sink2.


ThanksPF DIY 1 Error.fsm

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pf-diy-1-error.fsm (73.6 KiB)
Joerg Vogel avatar image Joerg Vogel PeterHe commented ·

@PeterHe , can you upload the pictures again, because I don’t see them. Thanks!

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Jason Lightfoot avatar image Jason Lightfoot ♦♦ PeterHe commented ·

I don't understand the question about the red decision point path. You've removed the decision that checked for the label boxpallet==1 so that was how you were doing it before. You replaced that with a pull from list that always sends the token to output1 even when it times out.


For the second part - use two ports from the exit transfer and send to one or the other depending on the condition as Jörg mentions - item.subnodes.length.


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PeterHe avatar image PeterHe Jason Lightfoot ♦♦ commented ·

Hi Jason Lightfoot、Joerg Vogel:

I want to do three things:

1、Empty pallet arrives first to DP2

2、The conveyor2 and converyor3 between DP2 and DP1 is buffer,

3、Buffer full. the empty pallet output by the red dot DP3 conveyor .

The reason for use "pull from list" is i'm not familiar with the "Decide".i also think the Decide is more reasonable.

Now "pull from list" is not ideal,the following problems exist:

Problem 1:operator1 handling boxes will be delayed,

Problem 2: The buffer of DP2 and DP1 is not ideal

The follow to New question:

Question1.1:I used"Pull from List" activies. pulling "Item bump list" the conveyor can be buffer pallet.But the conveyor gets stuck with the last token(sixth token), So is the method of "on item bump" reasonable?

Question1.2:How do i implement the first three things using the "Decide" method.


@Joerg Vogel @Jason Lightfoot

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Joerg Vogel avatar image Joerg Vogel commented ·

Question 2: You distinguish between an empty and loaded pallet by number of subnodes of the conveyor item.For example item.subnodes.length < 1 is empty.

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PeterHe avatar image PeterHe Joerg Vogel commented ·

PF DIY 1 Output by subnodes.fsmThanks for your help,the question2 is solved.

Queue's output usage condition port "item.subnodes.length<1" is good mothed.

A new question about question2:

I assign label name "emptypallet" for empty pallet and "boxpallet" for full pallet.

Question2.1:Can be use the "labelname" to set output port? how to do?


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Joerg Vogel avatar image Joerg Vogel PeterHe commented ·

That is not recommended. You set a general label name eg. MyitemState. Then you assign values to it like “empty”, ”filled”, “full”. Then you read the label MyitemState and compare the value. https://answers.flexsim.com/articles/124363/switch-by-case-in-process-flow.html

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PeterHe avatar image PeterHe Joerg Vogel commented ·

@Joerg Vogel

Only Unload box.fsm

Hi

There is one small problem with all this

1677934318323.jpg

How do I achieve this,Thank you in advance

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only-unload-box.fsm (83.2 KiB)
PeterHe avatar image PeterHe PeterHe commented ·
Question: How do I only unload box?
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