Little delays before pulling

My problem is the unwanted delay times just before pulling an item from a rack.

Please find the model in attach.
When the global variable gets a value smaller than 5, I want to pull one item from the rack.
If you look carrefully, you can see ASRS vehicle waits 0-10 time units before start moving after variable changes.
This little delays became very important for my model and I couldn't solve it.

Enver,

I can not find where you have the code that tells the ASRS to go and pick up a flowitem. For anybody to be able to give you much help you are going to have to explain in you post how you are making and where you are making the decisions in your model. How and where are you getting the ASRS to not pull items when the count is equal to 5?

From looking at the model it seems to me that the ASRS doesn't attempt to remove an item from the rack until a new item enters the rack but only if the global variable is less than 5. This would explain the delay you are seeing.

Good Luck,
Brandon

Dear Brandon,

First of all thank you for your fast reply.
Let me explain the logic in the model.
OnExit trigger of the rack increases global variable "gelen1".
OnExit trigger of processor decreases same variable.
Pull requirement of queue make the queue pull the items from the rack if the variable is less than 5.

But you are true, rack releases an item when a new item arrives.
I want it to release an item just at the time when variable decrease to 4.

How can I make it?

Thanks.

Enver,

The best way to accomplish what you are trying to do would be to close the output of the rack when the gelen1 is equal or greater than 5. Since you increment the number on exit of the rack I would put that code there. Next on exit of the processor put a check that looks at the gelen1 variable and opens the output of the rack if the value is less than 5. Being that you can only get a value of 5 and never go over, you could just decrement the variable and then open the output of the rack without the check. This way you can remove the pull logic on the conveyor and everything will still work fine.

The reason you were getting the delay is because the pull requirement on the conveyor doesn't update or check for a part all the time. It only does that when something changs with the rack: get a part, a part leaves, the output opens from being closed. So, even though you changed variable the pull requirement didn't recognize that something had changed and so didn't pull a part until a new item entered the rack.

If you control the flow of the model by opening and closing ports then the result of a change will be instantaneous and you won't have the problem you are seeing.

P.S. When you use a Global Variable like you are it doesn't go back to its original value when you reset the model. So in your case if the variable is equal to 5 then nothing happens anymore in the model.

Good Luck,
Brandon