This model shows how to propagate fixed-point data types in fixed-point S-Functions. It exercises a custom C language S-function written to enforce data types across multiple signals. This operation is available in Simulink® with the "Data Type Propagation" block, which can be used for comparison with this S-function example.
To see the source code for the S-function, use the right-click context menu to select "Block Parameters". When the dialog box appears, press the Edit button.