C Construct

float mySig;

extern float mySig;

Procedure

1. Open the example model ex_defn_decl.

2. In the Model Data Editor, open the Inports/Outports tab.

3. From the Change view drop-down list, select Design.

4. In the Model Data Editor, for the Inport block, set Signal Name to mySig.

5. Set Data Type to single.

6. From the Change view drop-down list, select Code.

7. For the Inport block, set Storage class to ExportToFile.

8. Set Header File to myDecls.h.

9. Set Definition File to myDefns.c. Click OK.

10. Generate code from the model.

Results

The generated header file myDecls.h declares the global variable myParam by using the extern keyword.

/* Declaration for custom storage class: ExportToFile */
extern real32_T mySig;                 /* '<Root>/In1' */

The generated source file myDefns.c defines and initializes myParam.

/* Definition for custom storage class: ExportToFile */
real32_T mySig;                        /* '<Root>/In1' */