how to control entities in the queue

I want to control the entities in the queue block. For example I have two entities in queue block and connected server has the capacity of 1 followed by another server with the capacity 1. Now I want that second entity only leaves the queue when 1st entity leaves the second server.

I think, this is control by writing code in "exit", of "event actions" in queue block.

[Natasa]

Hallo! Did you solve this problem?

Answer 1

[Shreshth]

Hey Asad,

To control entity departure in a Simulink Queue block:

1. Open the Queue Block: Double-click the Queue block in your model.
2. Access Event Actions: Go to the "Event Actions" tab.
3. Modify "Exit" Event:

• Write MATLAB code to control entity departure.
• Use a persistent flag to track if the first entity has left the second server.

Example code:

persistent firstEntityProcessed;
if isempty(firstEntityProcessed)
    firstEntityProcessed = false;
end

if firstEntityProcessed
    % Allow second entity to leave
else
    % Hold second entity in queue
end

% Update `firstEntityProcessed` when the first entity leaves the second server

4. Set Up State Update: Ensure firstEntityProcessed is updated when the first entity exits the second server.

5.Test: Run the simulation to verify behavior.

Hope it helps.