Integrate Custom Function Block in Generated Code

To integrate a custom function block, ExternallyDefinedBlock, this procedure uses the example plcdemo_external_symbols. To open the example, enter:

openExample('plcdemo_external_symbols');

1. In a Simulink^® model, add a MATLAB Function block.

2. Double-click the MATLAB Function block.

3. In the MATLAB^® editor, minimally define inputs, outputs, and stubs. For example:

   Functions that have only one output, no states, and do not access global variables are generated as FUNCTION in the generated structured text code.

   function Y = fcn(U,V)
   % Stub behavior for simulation. This block 
   % is replaced during code generation
   Y = U + V;

4. Change the MATLAB Function block name to ExternallyDefinedBlock.

5. Create a subsystem from this MATLAB Function block.

6. Complete the model to look like the Subsystem block in

   openExample('plcdemo_external_symbols');

   .

   

7. Open the Configuration Parameters dialog box for the model.

8. Add ExternallyDefinedBlock to PLC Code Generation > Identifiers > Externally Defined Identifiers.

9. The plcdemo_external_symbols model also suppresses K1 and InBus. Add these symbol names to the Externally Defined Identifiers field, separated by spaces or commas. For other settings, see the plcdemo_external_symbols model.

   

10. Save and close your new model. For example, save it as plcdemo_external_symbols_mine.

11. Generate code for the model.

12. In the generated code, look for instances of ExternallyDefinedBlock.

    The reference of ExternallyDefinedBlock is:

    

    The omission of ExternallyDefinedBlock is: