MatLab version compatibility with FAST V7 SimuLink S Function

Hoping somebody knows the answer to a quick question:

With which legacy versions of MatLab/SimuLink is the FAST V7 SimuLink 64bit S Function (as distributed on NWTC website) compatible? Without recompiling, that is.

We have some old legacy models (originally run in FAST6 using very old versions of 32bit MatLab) that we have picked up and we are unable to run them using the FAST V7 SimuLink 64bit S Function in versions of MatLab that include 2011b, 2013b, and 2016a. We have tried running the sample files included with FAST V7 with the same versions of MatLab and we are also finding that they will not run in our installations. In each case, we receive the error about obtaining sizes from MEX S-function, which we understand to typically be a classic sign of version incompatibility.

If there are other issues that can result in this error, I would welcome the feedback.

Yes, I know we could recompile, but we are hoping to avoid that complication if possible.

Yes, we can convert to FAST V8. Again, we are hoping to avoid that complication right now.

BTW, we had similar issues with running the FAST V8 SimuLink sample with the 64bit S Function (as distributed on NWTC website) in MatLab 2016a, although we were able to get it to run just fine in 2013b without recompiling. Hence, we took this error to primarily be due to the version incompatibility.

Any insights anyone has are very much welcome and appreciated.

Kyle K. Wetzel, Ph.D.
Wetzel Engineering

Dear Kyle,

According to the following forum post, the Simulink 64-bit S-Function for FAST v7 that NREL has released was compiled using MATLAB R2012a:

Best regards,

Dear Jason,

This problem persists when using MATLAB R2012a.

I am aware of some software packages that are sensitive to the OS of the machine on which they are installed. To your knowledge, does MATLAB also have this problem?

Dear Ryan,

Are you referring to different versions of Windows e.g. XP or 10? I’m not aware of specific problems, but that doesn’t mean there aren’t any.

Hopefully someone on this forum with more experience using the FAST-Simulink interface can comment.

Best regards,


That’s correct. Some software programs are sensitive to the version of Windows that is installed. I am curious if MATLAB also exhibits this behavior, possibly relating to the manner in which MATLAB sets the path to the S-Function.