Help Me in Debugging C Code to S-Function MATLAB

Hello Community,

I have .c code file ( for model predictive control) which I received from my professor. That code was written by one of student who is now graduated and I don't have any contact with him.

I am facing problem in compiling that code. I didn't have any experience about C programming language as well as S Function.

After watching few tutorials on Youtube I know how to call using Legacy Tool.

In def.OutputFcnSpec we need to specify our output but unfortunately I am not able to do it and contineously receiving error. I know there is no fault in the code but only mistake I am doing is that I can't able to define the def.OutputFcnSpec correctly.

I have attached the zip file to this question in which I want to compile mpcsolver.c file to use in S-Function block. In the zip file there is .m file which I code to call the legacy function. Please Help me.

Answer 1

[Sayan]

Hi Muhammad,

I understand from your issue that you need to create a ".mexXXX" (MATLAB executable) file from the source files "mpcsolver.c" and "EKFSolver.c" using the "Legacy Code Tool".

After looking at the source file, I could not find any "add" function, which is specified as "OutputFcnSpec" in the "code_to_call_s_function.m" file for the "Legacy Code Tool." If you are using a handwritten S-function, you still need to define the "add" function and make a call to it from "mdlOutputs".

Alternatively, as you have the "mpcsolver.c" written as "Level-2 MATLAB S-function", you can create the ".mexXXX" without the "Legacy Code Tool" by using the following command:

mex mpcsolver.c

This will create the MATLAB executable, which you can use in the S-Function block to create the desired block in the Simulink model. However, you need to specify the parameters of the S-function in the "S-function parameters" field, separated by comma.

You can find the following documentations on "Integrate C Functions Using Legacy Code Tool" , "S-Functions Incorporate Legacy C Code","Write Level-2 MATLAB S-Functions" and "S-Function" block for more useful information on them.

• "Integrate C Functions Using Legacy Code Tool" : https://www.mathworks.com/help/simulink/sfg/integrating-existing-c-functions-into-simulink-models-with-the-legacy-code-tool.html
• "S-Functions Incorporate Legacy C Code" : https://www.mathworks.com/help/simulink/sfg/example-using-s-functions-to-incorporate-legacy-c-code.html
• "Write Level-2 MATLAB S-Functions" : https://www.mathworks.com/help/simulink/sfg/writing-level-2-matlab-s-functions.html
• "S-Function" block : https://www.mathworks.com/help/simulink/slref/sfunction.html

Hope this helps in resolving the issue.