User`s guide

Examples of C MEX-File S-Function Blocks
3-77
/*
* Modes and zero crossings:
* If we have a variable step solver and this block has a continuous
* sample time, then
* o One mode element will be needed for each scalar output
* in order to specify which equation is valid (1), (2), or (3).
* o Two ZC elements will be needed for each scalar output
* in order to help the solver find the exact instants
* at which either of the two possible "equation switches."
* One will be for the switch from eq. (1) to (2);
* the other will be for eq. (2) to (3) and vise versa.
* otherwise
* o No modes and nonsampled zero crossings will be used.
*
*/
ssSetNumModes(S, DYNAMICALLY_SIZED);
ssSetNumNonsampledZCs(S, DYNAMICALLY_SIZED);
/*
* options
* o No mexFunctions and no problematic mxFunctions are called
* so the exception free code option safely gives faster simulations.
* o Scalar expansion of the inputs is desired. The option provides
* this without the need to write mdlSetOutputPortWidth and
* mdlSetInputPortWidth functions.
*/
ssSetOptions(S, ( SS_OPTION_EXCEPTION_FREE_CODE |
SS_OPTION_ALLOW_INPUT_SCALAR_EXPANSION));
} /* end mdlInitializeSizes */
/* Function: mdlInitializeSampleTimes =========================================
* Abstract:
* Specify that the block is continuous.
*/
static void mdlInitializeSampleTimes(SimStruct *S)
{
ssSetSampleTime(S, 0, INHERITED_SAMPLE_TIME);
ssSetOffsetTime(S, 0, 0);
}