Argument Specification for Simulink Function Blocks

When a Simulink Function block is within the scope of a Function Caller block, you do not have to specify the parameters. In such a case, the Function Caller block can determine the input and output argument specifications.

You specify arguments when a Simulink Function block is outside the scope of a Function Caller block. A Simulink Function block is considered to be out of scope of a Function Caller block when the two blocks are in separate models referenced by a common parent model.

Example Argument Specifications for Data Types

This table lists possible input and output argument specifications.

Simulink Function Block Data Type	Function Caller Block Expression	Description
`double`	`double(1.0)`	Double-precision scalar.
`double`	`double(ones(12,1))`	Double-precision column vector of length 12.
`single`	`single(1.0)`	Single-precision scalar.
`int8`, `int16`, `int32`	`int8(1)`, `int16(1)`, `int32(1)`	Integer scalars.
	`int32([1 1 1])`	Integer row vector of length 3.
	`int32(1+1i)`	Complex scalar whose real and imaginary parts are 32-bit integers.
`uint8`, `int16`, `int32`	`uint8(1)`, `uint16(1)`, `uint32(1)`	Unsigned integer scalars.
`boolean`	`boolean(true)`,`boolean(false)`	Boolean, initialized to true (1) or false (0).
`fixdt(1,16)` `fixdt (signed, word_length)`	`fi(0,1,16)` `fi (value, signed, word_length)`	16-bit fixed-point signed scalar with binary point set to zero. Fixed-point numbers can have a word size up to 128 bits.
`fixdt(1,16,4)`	`fi(0,1,16,4)`	16-bit fixed-point signed scalar with binary point set to 4.
`fixdt(1,16,2^0,0)`	`fi(0,1,16,2^0,0)`	16-bit fixed-point signed scalar with slope set to `2^0` and bias set to 0.
`Bus: <object name>`	`parameter object name`	`Simulink.Parameter` object with the `Value` parameter set to a MATLAB^® structure for the bus.
`Enum: <class name>`	`parameter object name`	`Simulink.Parameter` object with the `Value` parameter set to an enumerated value.
`<alias name>`	`parameter object name`	`Simulink.Parameter` object with the `DataType` parameter set to a `Simulink.AliasType` object and the `Value` parameter set to a value.

Input Argument Specification for Bus Data Type

Create a bus with two signals, and then specify the Input argument specification parameter for a Function Caller block. The Function Caller block calls a Simulink Function block that accepts the bus as input.

A bus input to a Function Caller block must be a non-virtual bus using a bus object.

Create a Simulink^® bus object myBus.
```
myBus = Simulink.Bus;
```

Add elements A and B.

myBus.Elements(1).Name = 'A';
myBus.Elements(2).Name = 'B';

Create a MATLAB structure myBus_MATLABstruct with fields A and B.
```
myBus_MATLABStruct.A = 0; 
myBus_MATLABStruct.B = 0;
```

Create a Simulink parameter object myBus_parameter and assign the MATLAB structure to the Value parameter.

myBus_parameter = Simulink.Parameter;
myBus_parameter.DataType = 'Bus: myBus';
myBus_parameter.Value = myBus_MATLABStruct;

For the Function Caller block dialog box, set the Input argument specification parameter to myBus_parameter.
For the Argument In block dialog box of the Simulink Function block, set the Data type parameter to Bus: myBus.

Input Argument Specification for Enumerated Data Type

Create an enumerated data type for the three primary colors, and then specify the Input argument specification parameter for a Function Caller block. The Function Caller block calls a Simulink Function block that accepts a signal with the enumerated type as input.

Create a MATLAB file for saving the data type definition. On the MATLAB toolstrip, select New > Class.
In the MATLAB editor, define the elements of an enumerated data type. The class BasicColors is a subclass of the class Simulink.IntEnumType.
```
classdef BasicColors < Simulink.IntEnumType
  enumeration
    Red(0)
    Yellow(1)
    Blue(2) 
  end
end 
```
Save the class definition in a file named BasicColors.m.
Create a Simulink parameter object myEnum_parameter and assign one of the enumerated values to the Value parameter.
```
myEnum_parameter = Simulink.Parameter;
myEnum_parameter.Value = BasicColors.Red;
```
For the Function Caller block dialog box, set the Input argument specification. to myEnum_parameter.
For the Argument In block dialog box within a Simulink Function block, set the Data type parameter to Enum: BasicColors.

Input Argument Specification for an Alias Data Type

Create an alias name for the data type single, and then specify the Input argument specification parameter for a Function Caller block. The Simulink Function block called by the Function Caller block also uses the alias name to define the input data type.

Create a Simulink alias data type object myAlias.
```
myAlias = Simulink.AliasType;
```
Assign a data type.
```
myAlias.BaseType = 'single';
```
Create a Simulink parameter object myAlias_parameter and assign the alias name to the DataType parameter.
```
myAlias_parameter = Simulink.Parameter;
myAlias_parameter.DataType = 'myAlias';
myAlias_parameter.Value = 1;
```
For the Function Caller block dialog box, set the Input argument specification parameter to myAlias_parameter.
For the Argument In block dialog box within a Simulink Function block, set the Data type parameter to myAlias.

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