C code to S function tutorials

Hi does anyone have any good tutorial examples that i can use to get to grips with using the legacy code toolbox ?

I have some C code and I want to learn effective ways to to turn it into S code to put in my simulink model. This model will eventually be working on a real time machine.

I have been told that the legacy code tool box is my best candidate. Does anyone have any informative tutorials that might help ?

Answer 1

[Suneesh]

There are several examples in Simulink documentation for the legacy code tool. Look under "Custom Blocks with S-functions, System Objects and Legacy Code Tool" in:

http://www.mathworks.com/help/simulink/examples/index.html#industrial-automation-applications

Do consider the S-Functions mentioned in Bruno's answer as well and choose the solution which seems more suitable for you.

Answer 2

[Bruno Pop-Stefanov]

I am not familiar with legacy_tool but there is another way to create an S-Function from C code.

You can call a binary from a Simulink model using MEX files. A MEX file is a binary compiled from C, C++ or Fortran code that is properly formatted to work with MATLAB code. Here is a short introduction:

Implementing S-Functions

and here is good starting point in the MATLAB documentation:

Introducing MEX-Files.

Answer 3

[Paul]

Thanks guys

I used the example to create an s function but then attempted to use the model wizard to compile the simulink model into my target machine but it comes up wth the error :

S-function 'ex_sfun_doubleit' in 'untitled/ex_sfun_doubleit' specifies option SS_OPTION_SFUNCTION_INLINED_FOR_RTW however a 'ex_sfun_doubleit.tlc' file could not be located in the current working directory, the S-function directory 'C:\Users\HIL\Documents\MATLAB\LEGACY_TEST', or the directory 'C:\Users\HIL\Documents\MATLAB\LEGACY_TEST\tlc_c'

can some one explain ?

[Kaustubha Govind]

As the documentation states, you also need to run legacy_code('sfcn_tlc_generate', def) in order to generate the ex_sfun_doubleit.tlc file.