Function-Call Generator

Provide function-call events to control execution of subsystem or model

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Libraries:
Simulink / Ports & Subsystems

Description

The Function-Call Generator block provides function-call events that execute a function-call subsystem or function-call model at the rate you specify with the Sample time parameter. A function-call subsystem or function-call model is a subsystem or model containing a Trigger block with its Trigger type parameter set to function-call.

To iteratively execute each function-call subsystem or function-call model multiple times at each time step, use the Number of iterations parameter.

To execute multiple function-call subsystems or function-call models in a specified order, use the Function-Call Generator block with a Function-Call Split block. For an example, see Function-Call Split.

To execute a function-call subsystem or function-call model intermittently, meaning not at every time step, select the Show enable port parameter. You can then use the input at the enable port to control when the block outputs function-call events. In effect, you can turn the block on and off as needed.

Note

Starting in R2025a, the Function-Call Generator block no longer behaves as a masked, linked block. To locate this block in a model programmatically, use the command find_system('BlockType','FunctionCallGenerator'). When you update from another release to R2025a, it is recommended that you fix any Function-Call Generator block whose link to a Simulink^® library is broken. Otherwise, the block will not be updated, and it will continue to behave as a masked block in the updated model. The mask behavior of this block will be removed in a future release. For more information about identifying broken library links in a model, see Display Library Links.

For versions prior to R2025a, to locate this block in a model programmatically, use the command find_system('MaskType','Function-Call Generator').

Examples

Function-Call Blocks Connected to Branches of the Same Function-Call Signal

In this model, a Function-Call Feedback Latch block is on the feedback signal between the branched blocks.

• Open Model

Function-Call Feedback Latch on Feedback Signal Between Child and Parent

In this model, the Function-Call Feedback Latch block is on the feedback signal between the child and the parent.

• Open Model

Single Function-Call Subsystem

In this example, a single function-call subsystem output serves as its own input.

• Open Model

Function-Call Subsystem with Merged Signal as Input

In this model a merged signal serves as the input to a function-call subsystem.

• Open Model

Ports

Input

Enable — Control signal input

scalar

The block outputs function-call events only when the input at this port is a positive number.

Dependencies

To enable this port, select the Show enable port check box.

Output

Function Call — Function-call event output

scalar | vector

Sends function-call events to the function-call input port of a function-call subsystem or function-call model.

Parameters

Sample time — Specify time interval

1 (default) | scalar | vector | -1

Specify the time interval between function-call events to a function-call subsystem or function-call model. If the actual calling rate for the subsystem or model differs from the time interval this parameter specifies, Simulink displays an error.

By default, the block uses a time interval of 1. To set a different interval, enter a valid sample time based on the table in Types of Sample Time, or specify -1 to inherit the time interval from the model.

Dependencies

To enable this parameter, clear the Show enable port check box. If you select Show enable port, sample time is automatically set to -1 (inherited).

Programmatic Use

Block Parameter: sample_time

Type: character vector

Values: '1' | scalar expression | vector expression | '-1'

Default: '1'

Number of iterations — Specify number of times to provide a function-call at each time step

1 (default) | integer

The value of this parameter can be a vector, where each element of the vector specifies a number of times to execute a function-call subsystem or model. If a vector is specified, then the block outputs a vector of function-call events, which can be split into individual function-call events using a Demux block and used to drive multiple function-call subsystems or models.

Suppose that you specify Number of iterations to be [3 2] and connect the output of this block to a Demux block, which is connected to the control ports of two function-call subsystems. In this case, the first function-call subsystem executes three times at each time step, and the second function-call subsystem executes two times at each time step.

If, however, you connect the output of this block to a single function-call subsystem or model, the total number of times that the function-call subsystem or model executes per time step is equal to the sum of the vector element values. So in the example above, specifying Number of iterations to be [3 2] and connecting the output of this block to a single function-call subsystem results in the function-call subsystem executing five times at each time step.

Settings

1

Provide function-call once during each time step.

integer

Signed or unsigned integer number. Provide the specified number of function calls at each time step.

Programmatic Use

Block Parameter: numberOfIterations

Type: character vector

Values: '1' | integer in quotes | vector of integers in quotes

Default: '1'

Disallow wide output — Prevent implicit expansion of output signal

off (default) | on

Unless this parameter is selected, the output of this block is expanded into a vector, if necessary, to drive the blocks to which it is connected. For example, if Number of iterations is set to 2 and Disallow wide output is not selected, and the output of this block is connected to a Demux block, which is in turn connected to three separate function-call subsystems, then each function-call subsystem receives two function-call events at each time step. A similar result occurs if the output of this block is connected to a Stateflow^® chart with multiple events. If Disallow wide output is selected in these situations, the software produces an error.

Select this parameter to prevent implicit expansion of the output signal.

Clear this parameter to allow implicit expansion of the output signal when appropriate.

Programmatic Use

Block Parameter: DisallowWideOutput

Type: character vector

Values: 'off' | 'on'

Default: 'off'

Show enable port — Add input port for control signal

off (default) | on

Select this parameter to add a control signal input port to the block. The block outputs function-call events only when the value at the control signal input port is a positive number.

Clear this parameter to remove the control signal input port. The block outputs function-call events at every time step.

Programmatic Use

Block Parameter: ShowEnablePort

Type: character vector

Values: 'off' | 'on'

Default: 'off'

Block Characteristics

Data Types
Direct Feedthrough	no
Multidimensional Signals	no
Variable-Size Signals	no
Zero-Crossing Detection	no

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced before R2006a

R2025a: Function-Call Generator block no longer behaves as linked, masked block

The Function-Call Generator block now behaves as a built-in block. For versions prior to R2025a, the block behaves as a masked, linked block. This change in block behavior enables the block to execute faster during simulation.