C-MEX S-Function Simulink Crash

Hello,

I generated an S-Function from C++ using the Legacy code to run in simulink. It does not work for all cases: If I change the input parameters or add a new block to run exactly as the existing block I get the message: Your model is still running. Do you want to close it? Yes/No. It does no matter what I choose and the program shuts down either way.

Can someone give me an explanation for that, and give me a hint in what I could do to avoid such behavior please?

I appreciate.

Answer 1

[Kaustubha Govind]

Perhaps your C code is causing some memory corruption? You could try debugging your S-function to see which line the crash happens at - this will give you a better idea of what might be going on.

[Daniel]

Hi Kaustubha,

Thank you.

If the code was causing memory corruption would not the simulation crashes every time? Or would not even be possible to compile? The fact is the S-function has been compiled and it works but not always.

What does it mean when Matlab pops up a message box with: "The model '' is still running. Do you want to stop and close it? Yes/No"? Clicking Yes or No yields to shutting the program down always.

Additionally C S-Functions do not give the same result as S-Functions from .m files. The plots of .m S-functions are continuous and smooth curves. The C S-Functions, on the other hand, give a "stairway" pattern as if it was discrete. Why do that happen?

Thank you again.

[Kaustubha Govind]

Daniel: No, I've seen that memory corruptions can produce sporadic failures. (Note that they are usually run-time failures that cannot be detected by the compiler)

Your question about your C S-function producing a non-continuous waveform seems like a separate issue. Could you please create a new question for this? You might need to provide snippets of your MATLAB code and your equivalent C code for contributors to provide meaningful feedback.