Writing S-Functions Overview of S-Functions Introduction What Is an S-Function? Using S-Functions in Models Passing Parameters to S-Functions When to Use an S-Function How S-Functions Work Implementing S-Functions S-Function Concepts S-Function Examples Writing M S-Functions Introduction S-Function Arguments S-Function Outputs Defining S-Function Block Characteristics A Simple M-File S-Function Example Examples of M-File S-Functions Example - Continuous State S-Function Example - Discrete State S-Function Example - Hybrid System S-Functions Example - Variable Sample Time S-Functions Processing S-Function Parameters Writing S-Functions in C Introduction Example of a Basic C MEX S-Function Templates for C S-Functions S-Function Source File Requirements The SimStruct Compiling C S-Functions How Simulink Interacts with C S-Functions Process View Data View Writing Callback Methods Converting Level 1 C MEX S-Functions to Level 2 Obsolete Macros Creating C++ S-Functions Overview Source File Format Making C++ Objects Persistent Building C++ S-Functions Creating Ada S-Functions Introduction Ada S-Function Source File Format Ada S-Function Specification Ada S-Function Body Writing Callback Methods in Ada Callbacks Invoked By Simulink Implementing Callbacks Omitting Optional Callback Methods SimStruct Functions Building an Ada S-Function Using an Ada S-Function in a Model Example of an Ada S-Function Creating Fortran S-Functions Introduction Level 1 Versus Level 2 S-Functions Creating Level 1 Fortran S-Functions The Fortran MEX Template File Example Inline Code Generation Example Creating Level 2 Fortran S-Functions Template File C/Fortran Interfacing Tips Constructing the Gateway An Example C-MEX S-Function Calling Fortran Code Porting Legacy Code Find the States Sample Times Multiple Instances Use Flints If Needed Considerations for Real Time Implementing Block Features Introduction Dialog Parameters Tunable Parameters Run-Time Parameters Creating Run-Time Parameters Updating Run-Time Parameters Input and Output Ports Creating Input Ports Creating Output Ports Scalar Expansion of Inputs Masked Multiport S-Functions Custom Data Types Sample Times Block-Based Sample Times Port-Based Sample Times Specifying the Number of Sample Times in mdlInitializeSizes Hybrid Block-Based and Port-Based Sample Times Multirate S-Function Blocks Synchronizing Multirate S-Function Blocks Work Vectors Work Vectors and Zero Crossings An Example Involving a Pointer Work Vector Memory Allocation Function-Call Subsystems Handling Errors Exception Free Code ssSetErrorStatus Termination Criteria S-Function Examples Example - Continuous State S-Function Example - Discrete State S-Function Example - Hybrid System S-Functions Example - Variable Step S-Function Example - Zero Crossing S-Function Example - Time Varying Continuous Transfer Function Writing S-Functions for Real-Time Workshop Introduction Classes of Problems Solved by S-Functions Types of S-Functions Basic Files Required for Implementation Noninlined S-Functions S-Function Module Names for Real-Time Workshop Builds Writing Wrapper S-Functions The MEX S-Function Wrapper The TLC S-Function Wrapper The Inlined Code Fully Inlined S-Functions Multiport S-Function Example Fully Inlined S-Function with the mdlRTW Routine S-Function RTWdata for Generating Code with Real-Time Workshop The Direct-Index Lookup Table Algorithm The Direct-Index Lookup Table Example S-Function Callback Methods Callback Method Reference mdlCheckParameters mdlDerivatives mdlGetTimeOfNextVarHit mdlInitializeConditions mdlInitializeSampleTimes mdlInitializeSizes mdlOutputs mdlProcessParameters mdlRTW mdlSetDefaultPortComplexSignals mdlSetDefaultPortDataTypes mdlSetDefaultPortDimensionInfo mdlSetInputPortComplexSignal mdlSetInputPortDataType mdlSetInputPortDimensionInfo mdlSetInputPortFrameData mdlSetInputPortSampleTime mdlSetInputPortWidth mdlSetOutputPortComplexSignal mdlSetOutputPortDataType mdlSetOutputPortDimensionInfo mdlSetOutputPortSampleTime mdlSetOutputPortWidth mdlSetWorkWidths mdlStart mdlTerminate mdlUpdate mdlZeroCrossings SimStruct Functions Introduction Language Support The SimStruct SimStruct Macros and Functions Listed by Usage Miscellaneous Error Handling and Status I/O Port Dialog Box Parameters Run-Time Parameters Sample Time State and Work Vector Simulation Information Function Call Data Type Real-Time Workshop Macro Reference ssCallExternalModeFcn ssCallSystemWithTid ssGetAbsTol ssGetContStateAddress ssGetContStates ssGetDataTypeName ssGetDataTypeId ssGetDataTypeSize ssGetDataTypeZero ssGetDiscStates ssGetDTypeIdFromMxArray ssGetDWorkComplexSignal ssGetDWorkDataType ssGetDWorkName ssGetDWorkUsedAsDState ssGetDWorkWidth ssGetdX ssGetErrorStatus ssGetInputPortBufferDstPort ssGetInputPortConnected ssGetInputPortComplexSignal ssGetInputPortDataType ssGetInputPortDimensionInfo ssGetInputPortDimensions ssGetInputPortDirectFeedThrough ssGetInputPortFrameData ssGetInputPortNumDimensions ssGetInputPortOffsetTime ssGetInputPortOverWritable ssGetInputPortRealSignal ssGetInputPortRealSignalPtrs ssGetInputPortRequiredContiguous ssGetInputPortReusable ssGetInputPortSampleTime ssGetInputPortSampleTimeIndex ssGetInputPortSignal ssGetInputPortSignalAddress ssGetInputPortSignalPtrs ssGetInputPortWidth ssGetIWork ssGetModelName ssGetModeVector ssGetModeVectorValue ssGetNonsampledZCs ssGetNumContStates ssGetNumDataTypes ssGetNumDiscStates ssGetNumDWork ssGetNumInputPorts ssGetNumIWork ssGetNumModes ssGetNumNonsampledZCs ssGetNumOutputPorts ssGetNumParameters ssGetNumRunTimeParams ssGetNumPWork ssGetNumRWork ssGetNumSampleTimes ssGetNumSFcnParams ssGetOutputPortBeingMerged ssGetOutputPortComplexSignal ssGetOutputPortDataType ssGetOutputPortDimensions ssGetOutputPortFrameData ssGetOutputPortNumDimensions ssGetOutputPortOffsetTime ssGetOutputPortRealSignal ssGetOutputPortReusable ssGetOutputPortSampleTime ssGetOutputPortSignal ssGetOutputPortSignalAddress ssGetOutputPortWidth ssGetPath ssGetParentSS ssGetPlacementGroup ssGetPWork ssGetRealDiscStates ssGetRootSS ssGetRunTimeParamInfo ssGetRWork ssGetSampleTimeOffset ssGetSampleTimePeriod ssGetSFcnParam ssGetSFcnParamsCount ssGetSimMode ssGetSolverName ssGetStateAbsTol ssGetT ssGetTNext ssGetTaskTime ssGetTFinal ssGetTStart ssIsContinuousTask ssGetUserData ssIsFirstInitCond ssIsMajorTimeStep ssIsMinorTimeStep ssIsSampleHit ssIsSpecialSampleHit ssIsVariableStepSolver ssPrintf ssRegAllTunableParamsAsRunTimeParams ssRegisterDataType ssSetCallSystemOutput ssSetDataTypeSize ssSetDataTypeZero ssSetDWorkComplexSignal ssSetDWorkDataType ssSetDWorkName ssSetDWorkUsedAsDState ssSetDWorkWidth ssSetErrorStatus ssSetExternalModeFcn ssSetInputPortComplexSignal ssSetInputPortDataType ssSetInputPortDimensionInfo ssSetInputPortFrameData ssSetInputPortDirectFeedThrough ssSetInputPortMatrixDimensions ssSetInputPortOffsetTime ssSetInputPortOverWritable ssSetInputPortReusable ssSetInputPortRequiredContiguous ssSetInputPortSampleTime ssSetInputPortSampleTimeIndex ssSetInputPortVectorDimension ssSetInputPortWidth ssSetModeVectorValue ssSetNumContStates ssSetNumDiscStates ssSetNumDWork ssSetNumInputPorts ssSetNumIWork ssSetNumModes ssSetNumNonsampledZCs ssSetNumOutputPorts ssSetNumPWork ssSetNumRunTimeParams ssSetNumRWork ssSetNumSampleTimes ssSetNumSFcnParams ssSetOffsetTime ssSetOptions ssSetOutputPortComplexSignal ssSetOutputPortDataType ssSetOutputPortDimensionInfo ssSetOutputPortFrameData ssSetOutputPortMatrixDimensions ssSetOutputPortOffsetTime ssSetOutputPortReusable ssSetOutputPortSampleTime ssSetOutputPortVectorDimension ssSetOutputPortWidth ssSetParameterName ssSetParameterTunable ssSetPlacementGroup ssSetRunTimeParamInfo ssSetSampleTime ssSetSFcnParamNotTunable ssSetSFcnParamTunable ssSetSolverNeedsReset ssSetStopRequested ssSetTNext ssSetUserData ssSetVectorMode ssUpdateAllTunableParamsAsRunTimeParams ssUpdateRunTimeParamData ssUpdateRunTimeParamInfo ssWarning ssWriteRTWMxVectParam ssWriteRTWMx2dMatParam ssWriteRTWParameters ssWriteRTWParamSettings ssWriteRTWScalarParam ssWriteRTWStr ssWriteRTWStrParam ssWriteRTWStrVectParam ssWriteRTWVectParam ssWriteRTWWorkVect ssWriteRTW2dMatParam