calling mex function from Simulink

I have a mex-fille build from C. I want to use it in Simulink but do I need to re write a S-function? I have tried to call without success a Matlab function.

Answer 1

[galaxy]

After you build mexw64 file successful, you can use S-Function block

if not, you need to build mex file by mex from S-function file.