Call a MEX function from Simulink

Dear all,

I have a .mex64 function that was build from C++ libraries (IPOPT solver) and is able to solve an optimzation problem (NLP constraint).

I can call this function from an .m file easily, but how should I do it in Simulink? An S-function will build a mex file, but I already have this MEX file.

The final goal is to run the optimization in real-time (Model Predictive Control) on a XPC target machine.

[Martijn]

Using a simple mex file function I get the following error:

"Only MATLAB files are supported for code generation. Unsupported file extension 'mexw64' [...]"

Answer 1

[Titus Edelhofer]

Hi Martijn,

for the xPC Target you will need to have the source code of IPOPT solver available. You can write your S-function and for compilation add all source files for IPOPT. Should work, but I guess your solver code (and therefore the resulting S-function) will be fairly large ...

Titus

[Martijn]

Thank you Titus!

I have the source code available (open-souce), but I have no idea how to wrap them inside an S-function. Do you have any references to examples of people who have done this?

And what will be the issue with the large S-function?

[Titus Edelhofer]

You just add the sources to your call to mex:

mex mysfunction.c ipopt1.c ipopt2.c ipopt3.c

Titus

[Kaustubha Govind]

Not sure if your MEX-function is written as an S-function (MEX-functions have one entry-point, named mexFunction; while S-functions have multiple entry-points like mdlInitializeSizes, mdlStart, mdlOutputs, mdlTerminate, etc.). Please be sure to follow the doc examples on S-functions.