How to change the input of a subsystem using open_system

There are two blocks in the model I designed: MATLAB Function and testSub.

At this time, I would like to control the input of testSub using MATLAB Function.

So I designed the code as below.

function y = fcn(u)
coder.extrinsic("set_param");
coder.extrinsic("close_system");
coder.extrinsic("open_system");

    set_param('untitled1/Subsystem/testSub','OpenFcn','');
    open_system('untitled1/Subsystem/testSub','OpenFcn');
    
y=1;

I want to set input to 'u' in set_param, but is there any way?

help will be appreciated.

Thanx

[Angelo Yeo]

Can you describe the desired workflow? What do you want to do in the end?

[eblee]

I want to run or stop the testSub block with a MATLAB Function. So I implemented code to control testSub using open_system.

At this time, I wonder if there is a way to directly set the input to testSub with set_param.

Answer 1

[Angelo Yeo]

I understood that you want to input a signal to input port. You don't need to use set_param. You can use Data Import/Export functionality in Simulink. See the documentation below which has examples on how to implement them.

Load Data to Root-Level Input Ports

Moreover, if you are to create test cases for Simulink models, you can consider using Simulink Test. You can author tests with shipped funcitonalities such as importing external file data for test cases, e.g., Excel spreadsheet. Please refer to the doc below for detailed information on how to create tests with user-defined input signals.

Use External File Data in Test Cases

[eblee]

I used set_param and open_system because I wanted all inputs to always be input in a state where the model was initialized.

Regarding your answer, is there a way to initialize the model every time for all inputs?

[Angelo Yeo]

You can use variables from base workspace. This means you can always set your variables as you need and run simulation with the sim command in an m-file.