reusable simulink functions prototype

Hello,

I am trying to use reusable simulink functions, and have the functions calls in different referenced models. But when generating c code I get:

Function caller prototype '' is not compatible with function definition.

I put the simulink function declaration in a referenced model "Model_B", but the function definition:

extern real_T Model_B_timestwo(RT_MODEL_Model_B_T * const Model_B_M, const real_T rtu_u);

doesn't match with the called function prototype:

extern real_T Model_B_timestwo(const real_T rtu_u);

This information is missing from the function call: the real time model data structure, and the pointer to the structure. How do I let the function caller know that the function called is a reusable one ? and that he shoulf include an entry point to it?

Best regards.

Answer 1

[sanidhyak]

Hi @Loubna Ibnou Fairouze,

I understand that you are trying to use reusable Simulink functions across different referenced models. When generating the C code, the issue which you faced usually occurs because by default, a referenced model generates a model data structure argument “(RT_MODEL_*)” in the function definition:

extern real_T Model_B_timestwo(RT_MODEL_Model_B_T * const Model_B_M, const real_T rtu_u);

while the caller expects a simpler reusable prototype:

extern real_T Model_B_timestwo(const real_T rtu_u);

The mismatch actually arises due to model reference interface settings and function packaging options.

To resolve this, kindly follow the steps below:

1. Open your referenced model (“Model_B”)

2. Go to Code Mappings > Functions

3. For your Simulink Function (“timestwo”), set:

- “Function Packaging = Reusable function”

4. In Model Settings (Ctrl+E) > Code Generation > Interface:

- Set Code interface packaging = Reusable function

- Disable "Pass root-level I/O as structure reference"

- Disable "Use model data structure"

5. In Code Mappings > Inports/Outports:

- Set storage class to Auto or ExportedGlobal

6. Now, regenerate code. The new generated prototype will be:

extern real_T Model_B_timestwo(const real_T rtu_u);

matching the caller function signature and hence resolving the incompatibility.

Kindly refer to the following official documentation for more details:

• https://www.mathworks.com/help/rtw/ug/reusing-functions-in-generated-code.html

Cheers & Happy Modeling!