What is S-Function?
S-Functions is computer language description of Simulink block
If written in MATLAB programming environment it is called M-file s-function
If written in ‘C/C++’ programming environment it is called C Mex s-function
What S-Function Do?
Allows you to add your own code to simulink model or environment
Code can be written for continuous, discrete or hybrid system
Can be use with Real Time Workshop
Real Time workshop generates code for Simulink/s-function to run in real time ………..faster
Here you can find good reference for that
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