Configure C/C++ S-Function Features

Configure block functionality for C/C++ S-functions

C/C++ S-functions allow you to configure extended block functionality through various callback and SimStruct methods.

Create and configure input/output ports.
Specify block-based and port-based sample times.
Pass dialog parameters to S-functions.
Model zero crossings and allocate memory for S-functions.
Configure code generation settings for S-functions.

S-Function Callback Methods

Input and Output

Initialize, Output, Terminate

`mdlInitializeSizes`	Specify the number of inputs, outputs, states, parameters, and other characteristics of the C MEX S-function
`mdlInitializeSampleTimes`	Specify the sample rates at which this C MEX S-function operates
`mdlOutputs`	Compute the signals that this block emits
`mdlUpdate`	Update a block's states
`mdlTerminate`	Perform any actions required at termination of the simulation

Signal Specification

`mdlSetDefaultPortComplexSignals`	Set the numeric types (real, complex, or inherited) of ports whose numeric types cannot be determined from block connectivity
`mdlSetDefaultPortDataTypes`	Set the data types of ports whose data types cannot be determined from block connectivity
`mdlSetDefaultPortDimensionInfo`	Set the default dimensions of the signals accepted or emitted by a C MEX S-function's ports
`mdlSetInputPortComplexSignal`	Set the numeric types (real, complex, or inherited) of the signals accepted by an input port
`mdlSetInputPortDataType`	Set the data types of the signals accepted by an input port
`mdlSetInputPortSampleTime`	Set the sample time of an input port that inherits its sample time from the port to which it is connected
`mdlSetOutputPortComplexSignal`	Set the numeric types (real, complex, or inherited) of the signals accepted by an output port
`mdlSetOutputPortDataType`	Set the data type of the signals emitted by an output port
`mdlSetOutputPortSampleTime`	Set the sample time of an output port that inherits its sample time from the port to which it is connected

Signal Dimensions

`mdlSetInputPortDimensionInfo`	Set the dimensions of the signals accepted by an input port
`mdlSetInputPortDimensionsModeFcn`	Propagate the dimensions mode
`mdlSetInputPortWidth`	Set the width of an input port that accepts 1-D (vector) signals
`mdlSetOutputPortDimensionInfo`	Set the dimensions of the signals accepted by an output port
`mdlSetOutputPortWidth`	Set the width of an output port that outputs 1-D (vector) signals

Signal Access

mdlSetWorkWidths Specify the sizes of the work vectors and create the run-time parameters required by this C MEX S-function

Sample Time

`mdlSetInputPortSampleTime`	Set the sample time of an input port that inherits its sample time from the port to which it is connected
`mdlSetOutputPortSampleTime`	Set the sample time of an output port that inherits its sample time from the port to which it is connected

Run-Time Parameters

`mdlSetWorkWidths`	Specify the sizes of the work vectors and create the run-time parameters required by this C MEX S-function
`mdlCheckParameters`	Check the validity of a C MEX S-function's parameters
`mdlProcessParameters`	Process the C MEX S-function's parameters

Model Reference

`mdlStart`	Initialize the state vectors of this C MEX S-function
`mdlProcessParameters`	Process the C MEX S-function's parameters
`mdlSetWorkWidths`	Specify the sizes of the work vectors and create the run-time parameters required by this C MEX S-function

Interactions with Simulink Engine

Simulation Information

`mdlGetOperatingPoint`	Return C MEX S-function's simulation operating point as a MATLAB data structure
`mdlSetOperatingPoint`	Restore operating point of C MEX S-function

Error Handling

`mdlStart`	Initialize the state vectors of this C MEX S-function
`mdlTerminate`	Perform any actions required at termination of the simulation

State and Work Vector

`mdlSetWorkWidths`	Specify the sizes of the work vectors and create the run-time parameters required by this C MEX S-function
`mdlZeroCrossings`	Update zero-crossing vector
`mdlInitializeConditions`	Initialize the state vectors of this C MEX S-function

SimStruct Functions

expand all

Input and Output

Signal Specification

`ssSetNumInputPorts`	Specify the number of input ports that a block has
`ssSetInputPortComplexSignal`	Set the numeric type (real or complex) of an input port
`ssSetInputPortDataType`	Set the data type of an input port
`ssSetInputPortDirectFeedThrough`	Specify the direct feedthrough status of a block's ports
`ssSetInputPortOffsetTime`	Specify the offset time of an input port
`ssSetInputPortRequiredContiguous`	Specify that the signal elements entering a port must be contiguous
`ssSetInputPortSampleTime`	Specify the sample time of an input port
`ssRegisterUnitFromExpr`	Register unit from unit expression
`ssSetInputPortUnit`	Specify unit of input port
`ssSetNumOutputPorts`	Specify the number of output ports that a block has
`ssSetOutputPortComplexSignal`	Set the numeric type (real or complex) of an output port
`ssSetOutputPortDataType`	Set the data type of an output port
`ssSetOutputPortOffsetTime`	Specify the offset time of an output port
`ssSetOutputPortSampleTime`	Specify the sample time of an output port
`ssSetOutputPortUnit`	Specify unit of output port
`ssGetInputPortComplexSignal`	Determine whether an input port accepts complex signals.
`ssGetInputPortDataType`	Get the data type of an input port
`ssGetInputPortDirectFeedThrough`	Determine whether a port has direct feedthrough
`ssGetInputPortFrameData`	Determine whether a port accepts signal frames
`ssGetInputPortOffsetTime`	Get the offset time of an input port
`ssGetInputPortRequiredContiguous`	Determine whether the signal elements entering a port must be contiguous
`ssGetInputPortSampleTime`	Get the sample time of an input port
`ssGetInputPortSampleTimeIndex`	Get the sample time index of an input port
`ssGetInputPortUnit`	Get unit of input port
`ssGetOutputPortComplexSignal`	Get the numeric type (complex or real) of an output port
`ssGetOutputPortDataType`	Get the data type of an output port
`ssGetOutputPortFrameData`	Determine whether a port outputs signal frames
`ssGetOutputPortOffsetTime`	Get the offset time of an output port
`ssGetOutputPortSampleTime`	Get the sample time of an output port
`ssGetOutputPortUnit`	Get unit of output port
`ssAllowSignalsWithMoreThan2D`	Enable S-function to work with multidimensional signals
`ssSetOneBasedIndexInputPort`	Specify that an input port expects one-based indices
`ssSetOneBasedIndexOutputPort`	Specify that an output port emits one-based indices.
`ssSetZeroBasedIndexInputPort`	Specify that an input port expects zero-based indices
`ssSetZeroBasedIndexOutputPort`	Specify that an output port emits zero-based indices.

Signal Access

`ssGetNumInputPorts`	Get the number of input ports that a block has
`ssGetNumOutputPorts`	Get the number of output ports that a block has
`ssGetInputPortBufferDstPort`	Determine the output port that is sharing this input port's buffer
`ssGetInputPortConnected`	Determine whether a port is connected to a nonvirtual block
`ssGetInputPortOptimOpts`	Get the reusability setting of the memory allocated to the input port of an S-function
`ssGetInputPortOverWritable`	Determine whether an input port can be overwritten
`ssGetInputPortRealSignal`	Get the address of a real, contiguous signal entering an input port
`ssGetInputPortRealSignalPtrs`	Get pointers to signals of type `double` connected to an input port
`ssGetInputPortSignal`	Get the address of a contiguous signal entering an input port
`ssGetInputPortSignalPtrs`	Get pointers to an input port's signal elements
`ssGetOutputPortConnected`	Determine whether an output port is connected to a nonvirtual block
`ssGetOutputPortBeingMerged`	Determine whether the output of this block is connected to a Merge block
`ssGetOutputPortOptimOpts`	Get the reusability setting of the memory allocated to the output port of an S-function
`ssGetOutputPortRealSignal`	Get a pointer to an output signal of type `double` (`real_T`)
`ssGetOutputPortSignal`	Get the vector of signal elements emitted by an output port
`ssSetInputPortOptimOpts`	Specify reusability of the memory allocated to the input port of an S-function
`ssSetInputPortOverWritable`	Specify whether one of an S-function's input ports can be overwritten by one of its output ports
`ssSetOutputPortOptimOpts`	Specify reusability of the memory allocated to the output port of an S-function
`ssSetOutputPortOverwritesInputPort`	Specify whether an output port can share its memory buffer with an input port
`ssSetInputPortAcceptExprInRTW`	Specify whether a block input accepts a nonconstant expression
`ssGetInputPortAcceptExprInRTW`	Determine whether a block input accepts a nonconstant expression
`ssSetOutputPortOutputExprInRTW`	Specify whether a block output generates a nonconstant expression
`ssGetOutputPortOutputExprInRTW`	Determine whether a block output generates a nonconstant expression

Signal Dimensions

`ssSetInputPortDimensionInfo`	Specify information about the dimensionality of an input port
`ssSetInputPortDimensionsMode`	Set the dimensions mode of the input port indexed by pIdx
`ssSetInputPortDimsSameAsOutputPortDims`	Set the dimensions of output port outIdx to be equal to the dimensions of input port inpIdx. This method is called from mdlSetWorkWidths.
`ssSetInputPortMatrixDimensions`	Specify dimension information for an input port that accepts matrix signals
`ssSetInputPortVectorDimension`	Specify dimension information for an input port that accepts vector signals
`ssSetInputPortWidth`	Specify the width of an input port
`ssPruneNDMatrixSingletonDims`	Prune trailing singleton dimensions
`ssSetCurrentOutputPortDimensions`	Set the current size corresponding to dimension dIdx of the output signal at port pIdx.
`ssSetOutputPortDimensionInfo`	Specify information about the dimensionality of an output port
`ssSetOutputPortDimensionsMode`	Set the dimensions mode of the output port indexed by pIdx
`ssSetOutputPortMatrixDimensions`	Specify dimension information for an output port that emits matrix signals
`ssSetOutputPortVectorDimension`	Specify dimension information for an output port that emits vector signals
`ssSetOutputPortWidth`	Specify the width of an output port
`ssSetOutputPortMatrixDimensions`	Specify dimension information for an output port that emits matrix signals
`ssAddOutputDimsDependencyRule`	Register a method to handle current dimensions update.
`ssAddVariableSizeSignalsRuntimeChecker`	Register a method to check the current input dimensions
`ssAllowSignalsWithMoreThan2D`	Enable S-function to work with multidimensional signals
`ssRegMdlSetInputPortDimensionsModeFcn`	Register the method to handle dimensions mode propagation for each input port.
`ssSetDWorkRequireResetForSignalSize`	Set the block flag for resetting the dIndex Dwork size upon subsystem reset.
`ssSetSignalSizesComputeType`	Set the type of output dependency on the input signal.
`ssSetVectorMode`	Specify the vector mode that an S-function supports
`ssGetCurrentInputPortDimensions`	Get the current size of dimension dIdx of input port pIdx
`ssGetCurrentInputPortWidth`	Get the total width (total number of elements) of the signal at input port pIdx
`ssGetInputPortDimensions`	Get the dimensions of the signal accepted by an input port
`ssGetInputPortDimensionSize`	Get the size of one dimension of the signal entering an input port
`ssGetInputPortDimensionsMode`	Get the dimensions mode of the input port indexed by pIdx
`ssGetInputPortNumDimensions`	Get the dimensionality of the signals accepted by an input port
`ssGetInputPortWidth`	Get the width of an input port
`ssGetCurrentOutputPortDimensions`	Get the current size of dimension dIdx of the signal at output port pIdx.
`ssGetCurrentOutputPortWidth`	Get the total width (total number of elements) of the signal at output port pIdx.
`ssGetOutputPortDimensions`	Get the dimensions of the signal leaving an output port
`ssGetOutputPortDimensionSize`	Get the size of one dimension of the signal leaving an output port
`ssGetOutputPortDimensionsMode`	Get the dimensions mode of the output port indexed by pIdx
`ssGetOutputPortNumDimensions`	Get the number of dimensions of an output port
`ssGetOutputPortWidth`	Get the width of an output port

Signal Region

`ssCallSelectedSignalsFcn`	Invoke the selected signals function for an S-function
`ssCallSigListCreateFcn`	Invoke the signal list creation function for an S-function
`ssCallSigListDestroyFcn`	Invoke the signal list destruction function for an S-function
`ssCallSigListUnavailSigAlertFcn`	Invoke the unavailable signal alert function for a signal list in an S-function
`ssCallGenericDestroyFcn`	Invoke the generic destruction function for an S-function
`ssCallGetPortNameFcn`	Get the name for a given port
`ssCallUnselectSigFcn`	Invoke the signal deselection function for an S-function
`gsl_FirstReg`	Get the first region of an element in a signal list
`gsl_nSigRegions`	Get the number of regions in an element of a signal list
`gsl_nSigs`	Get the number of signals in a signal list
`gsl_NumElements`	Get the number of elements in an element of a signal list
`gsl_PortObj`	Get the port associated with an element of a signal list
`gsl_TieWrap`	Determine whether an element in a signal list is contiguous
`gsr_Complex`	Determine whether the data in a signal region is complex
`gsr_currDims`	Access the current dimensions for a variable-sized signal in a signal region
`gsr_data`	Access the data in a signal region
`gsr_DataType`	Get the Simulink data type identifier for a region
`gsr_DataTypeSize`	Get the size of a single real value in a signal region
`gsr_Dims`	Access the values in the dimensions vector for a signal region
`gsr_nEls`	Get the number of elements in a region
`gsr_NextReg`	Get next region in the corresponding signal list
`gsr_NumDims`	Get the number of dimensions of the data in a signal region
`gsr_portObj`	Get the port associated with a signal region
`gsr_startIdx`	Get the index for the element in a signal list at the start of a region
`gsr_status`	Determine whether signal in a signal region is available
`gsr_Unit`	Get the Simulink unit identifier for a signal region
`gsr_M`	Determine number of rows in matrix signal
`gsr_N`	Get the number of rows in or width of a signal

Block Dialog Parameters

`ssGetDTypeIdFromMxArray`	Get the data type of an S-function parameter
`ssGetNumSFcnParams`	Get the number of parameters that an S-Function block expects
`ssGetSFcnParam`	Get a parameter of an S-Function block
`ssGetSFcnParamsCount`	Get the number of block dialog parameters that an S-Function block has
`ssSetNumSFcnParams`	Specify the number of parameters that an S-Function block has
`ssSetSFcnParamTunable`	Make a block parameter tunable

Data Type and Sample Time

Sample Time

`ssSetSampleTime`	Set the period of a sample time
`ssSetInputPortSampleTime`	Specify the sample time of an input port
`ssSetModelReferenceSampleTimeDefaultInheritance`	Specify that a referenced model containing this S-function can inherit its sample time from its parent model
`ssSetModelReferenceSampleTimeDisallowInheritance`	Specify that the use of this S-function in a referenced model prevents the referenced model from inheriting its sample time from its parent model
`ssSetModelReferenceSampleTimeInheritanceRule`	Specify whether use of this S-function in a referenced model prevents the referenced model from inheriting its sample time from its parent model
`ssSetNumSampleTimes`	Specify the number of sample times that an S-Function block has
`ssSetOffsetTime`	Set the offset time of a block
`ssSetTNext`	Set the time of the next sample hit
`ssSetVariableDiscreteSampleTime`	Register controllable sample time in a block
`ssSetNumTickstoNextHitForVariableDiscrete`	Schedule number of steps to next event
`ssSetNeedAbsoluteTime`	Specify if a block should use absolute time
`ssSetTimeSource`	Set source of time for asynchronous task
`ssGetInputPortSampleTime`	Get the sample time of an input port
`ssGetInputPortSampleTimeIndex`	Get the sample time index of an input port
`ssGetNumSampleTimes`	Get the number of sample times that a block has
`ssGetOffsetTime`	Get one of an S-function's sample time offsets.
`ssGetOutputPortSampleTime`	Get the sample time of an output port
`ssGetOutputPortSampleTimeIndex`	Get sample time index of output port
`ssGetPortBasedSampleTimeBlockIsTriggered`	Determine whether a block that uses port-based sample times resides in a triggered subsystem
`ssGetSampleTime`	Get one of an S-function's sample times.
`ssGetTNext`	Get the time of the next sample hit
`ssSetParameterTuningCompliance`	Specify sample time behavior and tunability for S-function blocks with port-based sample times
`ssGetParameterTuningCompliance`	Get the sample time behavior and tunability for S-function blocks with port-based sample times
`ssIsContinuousTask`	Determine whether a task is continuous
`ssIsSampleHit`	Determine whether the sample time is hit
`ssIsSpecialSampleHit`	Determine whether the sample time is hit
`ssSampleAndOffsetAreTriggered`	Determine whether a sample time and offset value pair indicate a triggered sample time
`ssSampleAndOffsetAreTriggeredOrAsync`	Determine whether a sample time and offset value pair indicate a triggered or asynchronous sample time
`ssSetAsyncTimerAttributes`	declares that the Simulink block requires a timer
`ssSetAsyncTimerDataType`	sets the data type of the asynchronous task
`ssSetAsyncTaskPriorities`	sets the Simulink task priority

Data Type

`ssRegisterDataType`	Register a custom data type
`ssRegisterTypeFromNamedObject`	Register a custom data type from a `Simulink.AliasType`, `Simulink.NumericType`, or `Simulink.Bus` object.
`ssSetDataTypeSize`	Set the size of a custom data type
`ssSetDataTypeZero`	Set the zero representation of a data type
`ssSetInputPortDataType`	Set the data type of an input port
`ssSetOutputPortDataType`	Set the data type of an output port
`ssGetDataTypeId`	Get the ID of a data type
`ssGetDataTypeIdAliasedThruTo`	Get the base data type associated with a data type alias
`ssGetDataTypeName`	Get the name of a data type
`ssGetDataTypeSize`	Get the size of a custom data type
`ssGetDataTypeZero`	Get the zero representation of a data type
`ssGetInputPortDataType`	Get the data type of an input port
`ssGetNumDataTypes`	Get number of data types registered for this simulation, including built-in types
`ssGetOutputPortDataType`	Get the data type of an output port
`ssGetOutputPortSignal`	Get the vector of signal elements emitted by an output port
`ssGetSFcnParamDataType`	Get the data type of a parameter for an S-Function block

Buses

`ssGetBusElementComplexSignal`	Get the signal complexity for a bus element
`ssGetBusElementDataType`	Get the data type identifier for a bus element
`ssGetBusElementDimensions`	Get the dimensions of a bus element
`ssGetBusElementName`	Get the name of a bus element
`ssGetBusElementNumDimensions`	Get the number of dimensions for a bus element
`ssGetBusElementOffset`	Get the offset from the start of the bus data type to a bus element
`ssGetNumBusElements`	Get the number of elements in a bus signal
`ssGetSFcnParamName`	Get the value of a block parameter for an S-function block
`ssIsDataTypeABus`	Determine whether a data type identifier represents a bus signal
`ssRegisterTypeFromParameter`	Register a data type that a parameter in the Simulink data type table specifies
`ssRegisterTypeFromNamedObject`	Register a custom data type from a `Simulink.AliasType`, `Simulink.NumericType`, or `Simulink.Bus` object.
`ssSetBusInputAsStruct`	Specify whether to convert the input bus signal for an S-function from virtual to nonvirtual
`ssSetBusOutputAsStruct`	Specify whether the output bus signal from an S-function must be virtual or nonvirtual
`ssSetBusOutputObjectName`	Specify the name of the bus object that defines the structure and type of the output bus signal

Strings

`ssGetInputStringLength`	Get length of string from input port
`ssGetStringDataTypeMaxLength`	Get maximum length of string data type
`ssIsStringDataType`	Determine if data type is string
`ssReadInputString`	Read C string from input port
`ssRegisterStringDataType`	Register string data type
`ssWriteOutputString`	Write C string to output port

Run-Time Parameters

`ssGetNumRunTimeParams`	Get the number of run-time parameters created by this S-function
`ssGetRunTimeParamInfo`	Get the attributes of a run-time parameter
`ssRegAllTunableParamsAsRunTimeParams`	Register all tunable parameters as run-time parameters
`ssRegDlgParamAsRunTimeParam`	Register a dialog parameter as a run-time parameter
`ssSetNumRunTimeParams`	Specify the number of run-time parameters created by this S-function
`ssSetRunTimeParamInfo`	Specify the attributes of a run-time parameter
`ssUpdateAllTunableParamsAsRunTimeParams`	Update the values of run-time parameters to be the same as those of the corresponding tunable dialog parameters
`ssUpdateDlgParamAsRunTimeParam`	Update a run-time parameter that corresponds to a dialog parameter
`ssUpdateRunTimeParamData`	Update the value of a run-time parameter
`ssUpdateRunTimeParamInfo`	Update the attributes of a run-time parameter

Function-Call Subsystems, Simulink Functions, and Model Reference

Function-Call Subsystems

`ssCallSystemWithTid`	Call the update and outputs methods of a function-call subsystem
`ssDisableSystemWithTid`	Disable a function-call subsystem connected to this S-function block
`ssEnableSystemWithTid`	Enable a function-call subsystem connected to this S-function
`ssGetCallSystemNumFcnCallDestinations`	Get the number of function-call destinations.
`ssGetExplicitFCSSCtrl`	Determine whether this S-function explicitly enables and disables the function-call subsystems that it invokes
`ssSetCallSystemOutput`	Specify that an output port is issuing a function call
`ssSetExplicitFCSSCtrl`	Specify whether this S-function explicitly enables and disables the function-call subsystem that it calls

Simulink Functions

`ssDeclareSimulinkFunction`	Declare Simulink Function with a given function prototype and scope.
`ssDeclareFunctionCaller`	Declare Simulink Function call with a given function prototype.
`ssCallSimulinkFunction`	Call a declared Simulink Function of a given function prototype at run time.
`ssQuerySimulinkFunction`	Determine if function name is declared as a Simulink Function.
`ssGetSimulinkFunctionInput`	Get a pointer to an input argument passed to a Simulink Function.
`ssGetSimulinkFunctionOutput`	Get a pointer to an output argument passed to a Simulink Function.
`ssSetSimulinkFunctionArgComplexity`	Declare complexity of a Simulink Function argument.
`ssSetSimulinkFunctionArgDataType`	Declare data type of Simulink Function argument.
`ssSetSimulinkFunctionArgDimensions`	Declare dimension of Simulink Function argument.

Model Reference

`ssRTWGenIsModelReferenceRTWTarget`	Determine if the model reference Simulink Coder target is generating
`ssRTWGenIsModelReferenceSimTarget`	Determine if the model reference simulation target is generating
`ssSetModelReferenceNormalModeSupport`	Specify if S-function can be used in referenced model simulating in normal mode
`ssSetModelReferenceSampleTimeDefaultInheritance`	Specify that a referenced model containing this S-function can inherit its sample time from its parent model
`ssSetModelReferenceSampleTimeDisallowInheritance`	Specify that the use of this S-function in a referenced model prevents the referenced model from inheriting its sample time from its parent model
`ssSetModelReferenceSampleTimeInheritanceRule`	Specify whether use of this S-function in a referenced model prevents the referenced model from inheriting its sample time from its parent model

Interactions with Simulink Engine

Simulation Information

`ssSetStateAbsTol`	Set the absolute tolerance used by a variable-step solver for a specific S-function continuous state.
`ssSetBlockReduction`	Request that the Simulink engine attempt to reduce a block
`ssSetOperatingPointCompliance`	Specify the behavior of a Simulink S-function when saving and restoring the operating point of a model containing the S-function
`ssSetOperatingPointVisibility`	Specify whether to make the S-function simulation operating point visible in model simulation operating point
`ssSetSolverNeedsReset`	Ask Simulink engine to reset solver
`ssSetSkipContStatesConsistencyCheck`	Ask Simulink engine to skip continuous state consistency check
`ssSetStopRequested`	Set the simulation stop requested flag
`ssGetBlockReduction`	Determine whether a block has requested block reduction before the simulation has begun and whether it has actually been reduced after the simulation loop has begun
`ssGetErrorStatus`	Get a character vector that identifies the last error
`ssGetFixedStepSize`	Get the fixed step size of the model containing the S-function.
`ssGetMaxStepSize`	Get the maximum step size used by the model containing the S-function.
`ssGetMinStepSize`	Get the minimum step size used by the model containing the S-function.
`ssGetSimMode`	Get the simulation mode of an S-Function block
`ssGetSimStatus`	Get the current simulation status of an S-Function block
`ssGetSolverMode`	Get the solver mode being used to solve the S-function
`ssGetSolverName`	Get the name of the solver being used to solve the S-function
`ssGetStateAbsTol`	Get the absolute tolerance used by the variable-step solver for a specified state
`ssGetStopRequested`	Get the value of the simulation stop requested flag
`ssGetT`	Get the current simulation time
`ssGetTaskTime`	Get the current time for the current task
`ssGetTFinal`	Get the simulation stop time
`ssGetTNext`	Get the time of the next sample hit
`ssGetTStart`	Get the simulation start time
`ssIsExternalSim`	Determine if the model is running in external mode.
`ssIsFirstInitCond`	Determine whether the simulation time is equal to the start time.
`ssIsMajorTimeStep`	Determine whether the simulation is in a major step
`ssIsMinorTimeStep`	Determine whether the simulation is in a minor step
`ssIsVariableStepSolver`	Determine if a variable-step solver is being used to solve the S-function
`ssRTWGenIsAccelerator`	Determine if the model is running in Accelerator mode.
`ssIsRapidAcceleratorActive`	Determine whether the model is running in Rapid Accelerator mode

Error Handling

`ssGetErrorStatus`	Get a character vector that identifies the last error
`ssGetLocalErrorStatus`	Get a character vector that identifies the last error
`ssPrintf`	Print a variable-content message
`ssSetErrorStatus`	Report an error
`ssSetLocalErrorStatus`	Report an error in a thread-safe manner
`ssWarning`	Display a warning message

Information and Options

`ssSetOptions`	Specify S-function options
`ssCallExternalModeFcn`	Invoke the external mode function for an S-function
`ssGetModelName`	Get the model name
`ssGetParentSS`	Get the parent of a SimStruct
`ssGetPath`	Get the path of a block
`ssGetRootSS`	Get the root of a SimStruct hierarchy
`ssGetUserData`	Access user data
`ssSetExternalModeFcn`	Specify the external mode function for an S-function
`ssSetPlacementGroup`	Specify the name of the placement group of a block
`ssSetUserData`	Specify user data
`ssSupportsMultipleExecInstances`	Specify that a For Each Subsystem block supports an S-function operating inside the subsystem.

State and Work Vector

`ssSetNumDWork`	Specify the number of Dwork vectors used by a block
`ssSetDWorkComplexSignal`	Specify whether the elements of a Dwork vector are real or complex
`ssSetDWorkDataType`	Specify the data type of a Dwork vector
`ssSetDWorkName`	Specify the name of a Dwork vector
`ssSetDWorkUsageType`	Specify how DWork vector is used in S-function
`ssSetDWorkUsedAsDState`	Specify that a Dwork vector is used as a discrete state vector
`ssSetDWorkWidth`	Specify the width of a Dwork vector

`ssGetNumDWork`	Get the number of Dwork vectors used by a block
`ssGetDWork`	Get a DWork vector
`ssGetDWorkComplexSignal`	Determine whether the elements of a Dwork vector are real or complex numbers
`ssGetDWorkDataType`	Get the data type of a Dwork vector
`ssGetDWorkName`	Get the name of a Dwork vector
`ssGetDWorkUsageType`	Determine how DWork vector is used in S-function
`ssGetDWorkUsedAsDState`	Determine whether a Dwork vector is used as a discrete state vector
`ssGetDWorkWidth`	Get the size of a Dwork vector
`ssGetdX`	Get the derivatives of a block's continuous states

`ssSetNumContStates`	Specify the number of continuous states that a block has
`ssSetNumDiscStates`	Specify the number of discrete states that a block has
`ssSetNumNonsampledZCs`	Specify the number of states for which a block detects zero crossings that occur between sample points

`ssGetContStates`	Get a block's continuous states
`ssGetDiscStates`	Get a block's discrete states
`ssGetRealDiscStates`	Get a block's discrete state vector
`ssGetNonsampledZCs`	Get the zero-crossing signal values
`ssGetNumContStates`	Get the number of continuous states that a block has
`ssGetNumDiscStates`	Get the number of discrete states that a block has
`ssGetNumNonsampledZCs`	Get the size of the zero-crossing vector

`ssSetNumRWork`	Specify the size of a block's floating-point work vector
`ssGetNumRWork`	Get the size of a block's floating-point work vector
`ssGetRWork`	Get a block's floating-point work vector
`ssGetRWorkValue`	Get an element of a block's floating-point work vector
`ssSetRWorkValue`	Set an element of a block's floating-point work vector
`ssSetNumIWork`	Specify the size of a block's integer work vector
`ssGetNumIWork`	Get the size of a block's integer work vector
`ssGetIWork`	Get a block's integer work vector
`ssGetIWorkValue`	Get an element of a block's integer work vector
`ssSetIWorkValue`	Set an element of a block's integer work vector
`ssSetNumPWork`	Specify the size of a block's pointer work vector
`ssGetNumPWork`	Get the size of a block's pointer work vector
`ssGetPWork`	Get a block's pointer work vector
`ssGetPWorkValue`	Get a pointer from a block's pointer work vector
`ssSetPWorkValue`	Set an element of a block's pointer work vector
`ssSetNumModes`	Specify the size of the block's mode vector
`ssGetNumModes`	Get the size of the mode vector
`ssGetModeVector`	Get the mode vector
`ssGetModeVectorValue`	Get an element of a block's mode vector
`ssSetModeVectorValue`	Set an element of a block's mode vector

Code Generation

`ssGetDWorkRTWIdentifier`	Get the identifier used to declare a DWork vector in code generated from the associated S-function
`ssGetDWorkRTWIdentifierMustResolveToSignalObject`	Get a flag indicating if a DWork vector resolves to a `Simulink.Signal` object
`ssGetDWorkRTWStorageClass`	Get the storage class of a DWork vector in code generated from the associated S-function
`ssGetDWorkRTWTypeQualifier`	Get the C type qualifier (e.g., `const`) used to declare a DWork vector in code generated from the associated S-function
`ssGetPlacementGroup`	Get the name of the placement group of a block
`ssRTWGenIsCodeGen`	Identify any code generation that is not used by the Accelerator.

`ssSetArrayLayoutForCodeGen`	Specify array layout of the S-function
`ssSetDWorkRTWIdentifier`	Specify the identifier used to declare a DWork vector in code generated from the associated S-function
`ssSetDWorkRTWIdentifierMustResolveToSignalObject`	Specify if a DWork vector resolves to a `Simulink.Signal` object
`ssSetDWorkRTWStorageClass`	Specify the storage class of a DWork vector in code generated from the associated S-function
`ssSetDWorkRTWTypeQualifier`	Specify the C type qualifier (e.g., `const`) used to declare a DWork vector in code generated from the associated S-function
`ssSetPlacementGroup`	Specify the name of the placement group of a block

`ssWriteRTW2dMatParam`	Write a matrix parameter to the `model.rtw` file
`ssWriteRTWMx2dMatParam`	Write a matrix parameter in MATLAB format to the `model.rtw` file
`ssWriteRTWMxVectParam`	Write a vector parameter in MATLAB format to the `model.rtw` file
`ssWriteRTWParameters`	Write tunable parameter information to the `model.rtw` file
`ssWriteRTWParamSettings`	Write values of nontunable parameters to the `model.rtw` file
`ssWriteRTWScalarParam`	Write a scalar parameter to the `model.rtw` file
`ssWriteRTWStr`	Write a character vector to the `model.rtw` file
`ssWriteRTWStrParam`	Write a character vector parameter to the `model.rtw` file
`ssWriteRTWStrVectParam`	Write a vector of character vector parameters to the `model.rtw` file
`ssWriteRTWVectParam`	Write a vector parameter to the `model.rtw` file
`ssWriteRTWWorkVect`	Write work vectors to the `model.rtw` file