Buffer Entrance Lock

[claire]

Hi,

I am creating a line that runs two different products in batches along the same process. The process starts with a buffer and I want the buffer to clear of one product before it lets the next product start. I have managed to do this by inserting a single proc before the buffer and locking the buffer entrance when the final product of one batch has left. The problem I now have is that the entrance won't unlock to let the next product through. Does anyone have any ideas how I can do this? I have attached an example of where I am up to so far.

Thanks,

Claire

[RalfTobel]

Hi Claire,

you have to add code to the exit control of the buffer which checks if the buffer runs empty.

And when this happen you can open the entrance again.

See attached model.

Regards,

Ralf

[claire]

That's great, thank you!

Just another question, if I increase the capacity on the buffer to the same size as the batch of products I've realised that the method doesn't stop the second parts from entering straight away. For some reason the first part that leaves the buffer doesn't affect the BuffName. Is there a better place to put the method to get the name of the MUs in the buffer to make sure that it won't let any different products in?

Thanks,

Claire

[RalfTobel]

You can use the pull control of the buffer. This control is called whenever a part tries to enter the buffer. The control can then decide if it allows the part to enter.

Just have a look in the online manual or the examples collection.

[RalfTobel · Accepted solution]

Attached you can find a model which shows how to use the pull control.

[claire]

That's great, thanks for all your help.

[Irina]

Hi All,

Building on this initial example, I need to simulate a line instead of a buffer. The logic is similar - let the line process MU of type "a" before accepting MU of type "b" onto the line.

I struggle to get the line going. Can anyone please check what I am doing wrong?

Many thanks

Kind regards

Irina

[Steffen_B]

You need to set minimum gap in the line, so that A can leave, before B starts.

[Irina]

working version attached; thanks Steffen!