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Make a block parameter tunable


void ssSetSFcnParamTunable(SimStruct *S, int_T param,
  int_T isTunable)



SimStruct representing an S-Function block.


Index of the parameter.


Valid values are SS_PRM_TUNABLE (true / tunable), SS_PRM_NOT_TUNABLE (false / not tunable), or SS_PRM_SIM_ONLY_TUNABLE (tunable only during simulation).


Use this macro in mdlInitializeSizes to specify whether a user can change a dialog parameter during the simulation. The parameter index starts at 0 and is less than ssGetSFcnParamsCount(S). This improves efficiency and provides error handling in the event that an attempt is made to change the parameter.

If you specify the SS_PRM_TUNABLE option, you must create a corresponding run-time parameter (see Creating Run-Time Parameters). You do not have to create a corresponding run-time parameter if you specify the SS_PRM_SIM_ONLY_TUNABLE option.

    Note   Dialog parameters are tunable by default. However, an S-function should declare the tunability of all parameters, whether tunable or not, to avoid programming errors. If the user enables the simulation diagnostic S-function upgrade needed, the Simulink® engine issues the diagnostic whenever it encounters an S-function that fails to specify the tunability of all its parameters.


C, C++


See the following S-functions for examples that use this function:

Introduced before R2006a

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