I have modelled a line with sensor.
at distance 5 m the Mu will be loaded on machine for processing, after processing the MU should be loaded back to line.
I have used method at control exit for machine
@.move(l1,7) but doesnot work . the m1 machine is blocked
Thank you for the help
Solved! Go to Solution.
When you want to move the MU back to the line, the assigned space is occupied by a queue of MUs. If the assigned space is not available, the move will not succeed.
You can move the MU from the SingleProc to a point after the sensor. Alternatively, you can put the MU onto a Container. You then move the MU from the Container to the SingleProc and vice versa when the processing has finished (@.move(@.predLocation)).
In the code, I have defined sensor position at 5 m ,
after processing the Mu is loaded on line at 7m, i.e. 2m away from the sensor position.
but still it doesnot work.
Of course, your exit-control of the SingleProc is rear-triggered and therefore it is not triggered at all. It should be front-triggered.
If you follow the course of events you can understand what is happening. First MU: everything OK. Second MU: 1) arrives at the sensor, while the SingleProc is occupied. 2) Moving to the SingleProc is not possible, so it remains on the Line. 3) Both move on when the first MU is put back onto the line.
I am not sure if this is the intended behavior of the software.
In your case I think the easiest way forward is to use a product carrier that is kept waiting at the sensor until the MU is moved back onto it.
I doubt if it does justice to the real constraints as they happen in your case. If the product is really taken off the line, ok. If the product is worked while it stays on the conveyor, this is not really correct. I thought of an alternative: in the sensor-control you can use the method "create" to put a "copy" of the MU on the conveyor into the SingleProc. In the method your first stop the original MU (stopped:=true), then wait until the copy has finished (waituntil statement) and then unstop the original MU (stopped:=false).
in my case object is taken offline , processed and then put back to the line.
But your point is valid porceesing is on line.
Thank you , you given me new insight.
is there any possibility to model an assembly line moving on conveyor( typical automotive assembly line)?
can I use the approach as you mentioned create copy and process...
thank you nocheinmal.
The level of detail that you put into you model depends on its purpose. Although in many automotive final assembly cases the products keeps moving, it is often not needed necessary to model it in that detail in Plant Simulation. In general I would start with the standard Assembly object.
A generic approach to get this level of detail could be the following. Use a track or line for the main product. Specify a start and a finish sensor between which the work at the station (e.g. a SingleProc with a buffer) should happen. When the start sensor is triggered, you create an MU in the buffer. When the main MU reaches the finish sensor on the line/track, you check if the processing has been completed already.
But, again, this detail level may be too much for many purposes.