FAST S-function direct feedthrough error


I’ve compiled my own version of FAST for swept blades in a MATLAB S-function. My code was based on FAST v6.0 and I used modified versions of FASTGateway and FASTDynamics from v6.10.

The model starts (reads inputs files, opens output file and prints headers) and then crashes MATLAB, given a fairly cryptic error regarding “input port direct feedthrough setting”. Please let me know if you have any experience with this. The help information is all in regards to c-programming.


The error message said to compile with the mex -g option for diagnostics. I recompiled with this option, and I did not get any new messages during the compilation. I then tried to run a simulation with the new SFunc, and it ran with no errors…funny MATLAB.

Turns out my problem was in Read_FAST_input.m; I did not include the new DOFs for blade twist. For some crazy reason, the program would run if I compiled the mex file with the -g option, but have strange control behavior. But after I fixed the Read_FAST_input.m file, the simulation ran normally and I recompiled mex without the -g option (now optimizes) and it ran fine…