How to connect matlab and C# to create a winform gui to run a simulink model

I am new to Matlab and trying to code a winform based GUI for a simulink model in C#. But i had issue about how to communicate them efficiently.

2 different ways i tried:

1) I tried is COM communication between C# to matlab but after loading model, it was frozen.

C# script for communicating matlab over COM:

MLApp.MLApp matlab = new MLApp.MLApp();
matlab.Visible = 0;
matlab.Execute(@"cd('path to model')");
matlab.Execute("model");
matlab.Execute("set_param('model','SimulationCommand','start')");

It looks like a buffer overflow to me but I couldn't find any resources on the subject.

How can i prevent freezing?

2) I tried to communicate c# and matlab to control simulink model using udp protocol. I coded a matlab script to be bridge. However, i realized that i need to create more than one thread that will communicate with each other. Eventhough i used parellel computing toolbox in matlab, i can not accomplish it.

matlab script :

u = udp('', 'LocalHost', '127.0.0.1', 'LocalPort', 49013);
fopen(u);
while(true)
    command = fread(u);

   if(command == 1)
        %start model 
        set_param('model','SimulationCommand','start')
      
    elseif(command == 3)
        %pause model 
        set_param('model','SimulationCommand','pause')
    .
    .
    .
    else(command == 4)
        %stop model 
        set_param('model','SimulationCommand','pause')
    end
end

Is there a way to communicate threads each other in matlab?

Any suggestion would be nice.

[Mario Malic]

Matlab_Inst = actxserver('matlab.application')
Matlab_Inst.Execute("open_system('sldemo_autotrans')")

Don't know what's the purpose of @ in your cd command.

These two lines open up simulink for me.

[John Smith]

I think there is confusion because the code you shared is for matlab but in my question I tried to communicate with C# and matlab over COM. I edited question to clarify it. Thank you for your answer.

I will try to implement your suggestion to my matlab script that i designed as bridge between simulink and C#.

Thanks again.

Btw, @ is a 3 notation for string :

https://stackoverflow.com/questions/556133/whats-the-in-front-of-a-string-in-c

[Mario Malic]

That's correct, so this would be the change in your C# setup.

matlab.Execute("cd('path to model')");
matlab.Execute("model");
% or
% matlab.Execute("open_system(model)");

[John Smith]

I tried but it continues to freeze.

Thanks again.

[Mario Malic]

Try first loading simulink without window and then try to load the model, as it takes some time to start up.

start_simulink

What you can do as well is to leave the MATLAB window visible, and press control-c when it freezes so it will throw an error so you can know what the issue is.

[John Smith]

It worked.

Thank you :D

[Mario Malic]

Ok, then I'll post my comments as an answer so you can close this question.

Answer 1

[Mario Malic]

Based on the comments section, looks like this would be the way to start up the Simulink externally without freezing.

matlab.Execute("cd('path to model')");
matlab.Execute("start_simulink")
matlab.Execute("model");
% or
% matlab.Execute("open_system(model)");