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Setting up a basic Prestop

Valued Contributor
Valued Contributor

Hello, I apologize if this has already been covered, or if it is a really simple solution. I am very new to Simtalk and programming in general.

 

I am trying to model a prestop for a lift and transfer on a conveyor. I am using a combination of two lines, a converter, and a method to do this. The first Line is the input line with the "Prestop" at the end. (Modeled by the exit behaviour) The second line is a small distance of conveyor between the prestop and the lift and transfer, and the converter is the lift and transfer.

 

My thought was using this code:

if LT74.occupied = true or Line5.occupied = true then
Line.ExitLocked := true
else
Line.ExitLocked := false
end

 

with LT74 being the converter, Line5 being the second intermediate line, and Line being the input line; I could have the MU's be stopped at the end of the input line anytime there is an Mu on the intermediate line or the converter.

 

However, this is not working. Anytime I run the simulation all the Mu's get stuck at the end of the input line like they should when the intermediate line or converter are occupied, but the neither object is occupied. I even ran a test method to print the occupied status of both just to check.

 

Please help, it is probably something simple I'm missing.

19 REPLIES

Re: Setting up a basic Prestop

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor
if this a an exit control front, you need to call @.move at the end to transfer the part. This will not work with your code. But try this:
waituntil LT74.occupied = false or Line5.occupied = false prio 1
@.move
Steffen Bangsow
freelance simulation specialist  
web: www.bangsow.eu
mail: steffen@bangsow.net

Re: Setting up a basic Prestop

Valued Contributor
Valued Contributor

Ok that worked, but I have another problem now. I actually changed your code to:

waituntil LT74.occupied = false and Line5.occupied = false prio 1
@.move

 

I did this because it was letting multiple MU's through and I only want one at a time.

 

My new problem is that is it works, but after the first MU goes through the converter all consecutive MU's pause at the intermediate line for somewhere between 5 and 10 seconds before moving on to the converter. I can't find any reason for this.

Re: Setting up a basic Prestop

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor
you have a short time at the transfer between the elements, where both elements are occupied by the mu. So the converter keeps awhile occupied during unloading.
But try this:
waituntil LT74.numMu= 0 and Line5.occupied = false prio 1
@.move

So you can skip the unloading time, because numMu depends on the booking point of the MU (if you set the booking point at the front of the MU)..
Steffen Bangsow
freelance simulation specialist  
web: www.bangsow.eu
mail: steffen@bangsow.net

Re: Setting up a basic Prestop

Valued Contributor
Valued Contributor

I just tried that, and I am still having the same problem. I tried switching both to .numMU just to check and it is still pausing at the end of the intermediate line.

Re: Setting up a basic Prestop

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

set a breakpoint at @.move

then you can check the position of the previous MU

 

 

Steffen Bangsow
freelance simulation specialist  
web: www.bangsow.eu
mail: steffen@bangsow.net

Re: Setting up a basic Prestop

Valued Contributor
Valued Contributor
I'm not entirely sure what is happening. Basically, with the breakpoint: entity:1 hits. I hit continue and all is well. Then entity:2 hits as soon as Entity:1 is off the converter, but when I hit continue entity:2 pauses. And so on with all the entities after the first pausing.

Re: Setting up a basic Prestop

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor
hard to say, do you set automatic stop and acceleration in the line, in this case the line need first to accelerate; or you set cycle time in the line, than the MUs have to wait for the next gate... but sometimes it is only a matter of animation; switch the eventcontroller to realtime x and try it again
Steffen Bangsow
freelance simulation specialist  
web: www.bangsow.eu
mail: steffen@bangsow.net

Re: Setting up a basic Prestop

Valued Contributor
Valued Contributor
I have the acceleration and automatic stop both turned off, and the cycle time is set to 0, so basically off. I have actually been running the simulation in real time this whole time. Would it help if I send the file?

Re: Setting up a basic Prestop

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

yes, i will have a look on it

Steffen Bangsow
freelance simulation specialist  
web: www.bangsow.eu
mail: steffen@bangsow.net