How to set the output port type in dependence on an parameter - S Function

Hello,

i'm trying to write an S-Function which allows to set the output port type dependence on one of the parameter? What i already tried:

static void mdlOutputs(SimStruct *S, int_T tid)
{
DTypeId y0DataType = ssGetSFcnParam(S,2);
    switch(y0DataType)
    {
        case SS_INT8:
        {
         int8_T            *pY0 = (int8_T *)ssGetOutputPortSignal(S,0);    
         pY0[0] = 0;
         break;
        }
        case SS_UINT8:
        {
         uint8_T            *pY0 = (uint8_T *)ssGetOutputPortSignal(S,0);     
         pY0[0] = 13;
         break;
        } 
        default:
        {
         uint8_T            *pY0 = (uint8_T *)ssGetOutputPortSignal(S,0);     
         pY0[0] = 7;  
        }
    }
}

I can compile it and run the corresponding simulink model, but it doesn't work. Can me tell anyone why?

Regards V.Sadiku

[Jordan Monthei]

Could you go into more detail as to how it does not work? Is there an error that occurs during simulation? Is it not outputting as you would expect, in which case, what are you expecting and what are you seeing?

[Valmir Sadiku]

Simulink sets the output port type to 'double' and the attached display shows a strange value -> 3.953e-323). The parameter in the mask are set to"uint8", so i expected that simulink will set this one as output type. Maybe i have to do it another way, but i'm at a loss with this Problem.

[Valmir Sadiku]

If i try to do this in this way:

static void mdlInitializeSizes(SimStruct *S)
{
......
...
ssSetOutputPortDataType(S, 0, ssGetSFcnParam(S,2));

 ....
}

After recompiling it works without any error message, but if i run that corresponding simulink model it will give the following error in the Matlab command window:

Attempt to  use invalid data type id -5373248

And the Simulink model freezes, and i have to restart matlab.

Answer 1

[William James]

hello,

 i met the problem as you ! if you resolved it ,please tell me how to set the output type .

thank you with Hz

[Kaustubha Govind]

Do you validate the value entered for the parameter is a valid datatype ID before configuring it as the output datatype in mdlInitializeSizes?