topic Re: Stopping and Resuming stations on conveyor (>2 stations) in FlexSim Forum

Stopping and Resuming stations on conveyor (>2 stations)

bobby_lutz — Thu, 29 Dec 2022 18:28:54 GMT

[ FlexSim 22.1.0 ]

I am trying to build a conveyor line with 10 stations (varying process times). I want to stop objects from moving to the next station until the next station is empty.

I tried using logic from https://answers.flexsim.com/questions/53474/stopping-and-resuming-objects-using-conditions-in.html?childToView=133861#answer-133861. When I add a third station the objects move from station 1 to station 2 when 2 is complete with processing.

Re: Stopping and Resuming stations on conveyor (>2 stations)

bobby_lutz — Thu, 29 Dec 2022 21:35:06 GMT

I converted the conveyor/stations to processors. I highly recommend this for basic assembly line sims.

Re: Stopping and Resuming stations on conveyor (>2 stations)

kavika_faleumu — Thu, 29 Dec 2022 21:53:44 GMT

Hey @Bobby L, the logic you posted will only work for two stations because the Process Flow only watches for the state of the second station. I modified that model to use an Object Process Flow and attach several stations to it. An Object Process Flow allows you define logic once for a set of machines/processes that use the same logic.

I started by adding more Stations and then A-connecting them together so each one knew which one was ahead of it.

Most of the Process Flow logic was the same, but I had to change a few things. First was the "Decide" activity's conditional statement. Before it was checking if the station ahead was "idle", but there was a problem - when a station was finished processing, it automatically set the station's state to "idle". This meant that if a box was ready to move and the box ahead of it was also waiting to move but not processing, the previous box would move ahead anyway. I changed it so it would look at whether or not there was an "active item" at the next station.

For a similar reason, I had to change the logic for waiting till the next station was open. I simply changed it to be "On Continue".

Hope this helps.

Multiple Station Stops.fsm

Re: Stopping and Resuming stations on conveyor (>2 stations)

andrew_o2 — Thu, 05 Jan 2023 22:03:21 GMT

Hi @Bobby L, was Kavika F's answer helpful? If so, please click the "Accept" button at the bottom of their answer. Or if you still have questions, add a comment and we'll continue the conversation.

If we haven't heard back from you within 3 business days we'll auto-accept an answer, but you can always unaccept and comment back to reopen your question.