To model your design, you can integrate external software with your real-time application. You can access external software with Simulink® S-Function blocks written in C or in Fortran. Using Fortran requires processing steps beyond the steps required to write an S-function in C.
Define custom block functionality with MATLAB®, C, C++, or Fortran code
Legacy Code Integration (Simulink)
Integrate existing C or C++ functions, such as device drivers or external simulation code
S-Functions (Simulink Coder)
Develop S-function to represent external code and inline S-function with Target Language Compiler (TLC) block target file