Function-Call subsystems with S-Functions does not work in two differrent version matlab with same compiler

I tried to implement function-call subsystem with S-Function, block can work with matlab version 2019B, but it did not work with matlab version 2021A.

Two version matlab (2019B and 2021A) using same compiler

• Matlab version:

• Compiler:

Configure function-call subsystem with S-Function:

• In mdlInitializeSizes, set the data type of the S-function output port and configure block properties:

    ssSetNumContStates(S, 0);
    ssSetNumDiscStates(S, 0);

    if (!ssSetNumInputPorts(S, 0)) return;

    if (!ssSetNumOutputPorts(S,1)) return;
    ssSetOutputPortWidth(S, 0, 1);

    /* All output elements are function-call, so we can set the data type of the
     * entire port to be function-call. */
    ssSetOutputPortDataType(S, 0, SS_FCN_CALL);

    ssSetNumSampleTimes(   S, 1);
    ssSetNumRWork(         S, 0);
    ssSetNumIWork(         S, 0);
    ssSetNumPWork(         S, 0);
    ssSetNumModes(         S, 0);
    ssSetNumNonsampledZCs( S, 0);

    /* specify the sim state compliance to be same as a built-in block */
    ssSetOperatingPointCompliance(S, USE_CUSTOM_OPERATING_POINT);

    ssSetOptions(S, SS_OPTION_USE_TLC_WITH_ACCELERATOR |
                    SS_OPTION_CALL_TERMINATE_ON_EXIT |
                    SS_OPTION_CAN_BE_CALLED_CONDITIONALLY |
                    SS_OPTION_EXCEPTION_FREE_CODE |
                    SS_OPTION_ASYNCHRONOUS_INTERRUPT |
                    SS_OPTION_SFUNCTION_INLINED_FOR_RTW |
                    SS_OPTION_DISALLOW_CONSTANT_SAMPLE_TIME);
    
    /* Set model reference supported & sample time inheritance rule in model reference of S-function */
    ssSetModelReferenceNormalModeSupport(S, MDL_START_AND_MDL_PROCESS_PARAMS_OK);
    ssSetModelReferenceSampleTimeInheritanceRule(S, USE_DEFAULT_FOR_DISCRETE_INHERITANCE);

• In mdlInitializeSampleTimes, specify that an output port is issuing a function call and set sample time:

    ssSetSampleTime(S, 0, -1.0);
    ssSetOffsetTime(S, 0, 0.0);
    
    ssSetCallSystemOutput(S,0);  /* call on first element */

• In mdlStart, init value for userData

    UserDataType* userData = ssGetUserData(S);
    userData->condition = 0U;

• Execute the subsystem in mdlOutputs, execute the subsystem:

        UserDataType* userData = ssGetUserData(S);
mexPrintf("--------------------------\n");

    if (ssIsMajorTimeStep(S) == true) {

        userData->condition = userData->condition + 1U;

mexPrintf("current time %2.20f\n", ssGetT(S));
mexPrintf("userData->condition %u\n", userData->condition);
    
        if ((userData->condition % 10) == 0U) {
            ssCallSystemWithTid(S, 0, tid);
mexPrintf("calling\n");
        }
    }

• In mdlTerminate, free userData

    UserDataType* userData = ssGetUserData(S);
    /* Free memory for user data */
    free(userData)  

The model:

The result and log when I run moel in two matlab version:

Why are these different phenomenon on two matlab version?

Can anyone answer my questions? Thanks in advance

[Shivam Malviya]

Hi Hoa,

I understand that a Simulink model produces different outputs when run on different MATLAB versions.

Can you share the following information to understand the query better;

1. Simulink model file, s-function files, and any relevant files required to reproduce the issue.
2. The precise steps needed to reproduce the issue.

Regards,

Shivam Malviya

[Hoa Dang]

Hi Shivam,

Thanks for your answer,

1. I add model information in attached file
2. About procedure of the issue, you can mex the s-funtion file and run model in attached file

• I using an example function-call subsystem model of matlab and replace sfun_fcncall block with my s-function
• And change configuration "Solver" to "Fixed-step" only