Hi Alessandro Mutasci,
I understand that you are facing difficulties conceptualizing defining variables and managing them in S functions.
To initialize variables which in your case is an array, you need to first allocate the appropriate amount of space. You can use the “ssSetUserDataSize” and “ssSetOptions” functions for this purpose.
ssSetUserDataSize(YourStructElement, sizeof(double) * ARRAY_SIZE);
Later, you can follow basic C constructs and paradigms to input a variable, loop over the array and assign data.
I would highly recommend looking at S function examples from the MATLAB documentation here https://www.mathworks.com/help/simulink/sfg/s-function-examples.html to gain more clarity.
