Main Content

FMU

Include Functional Mockup Unit (FMU) in model

  • Library:
  • Simulink Extras / FMU Import

  • FMU block

Description

The FMU block imports existing functional mockup units (FMUs) into Simulink®. The block automatically selects an FMU mode based on the existing FMU you want to import:

  • Co-Simulation — Integrate FMUs that implement a Functional Mock-up Interface (FMI) Co-Simulation interface. These FMUs may contain local solvers that are used for tool coupling.

  • Model Exchange — Integrate FMUs that implement an FMI Model Exchange interface. These FMUs do not contain local solvers. Instead, they inherit solvers from Simulink.

This block supports FMI versions 1.0 and 2.0. For FMI version 2.0, if your FMU contains both Co-Simulation and Model Exchange elements, the block detects them and prompts you to select the mode you want the block to operate in.

To use this block, you must first have an existing FMU, exported from another tool, or authored in C language.

Ports

Output Arguments

expand all

Placeholder port that produces no output as is. Input and output ports are configured when an actual FMU is imported into the block. Both input and output ports support numerical and string data types.

Parameters

expand all

Specify the name of an FMU, with or without the file extension. This entry is case sensitive. The FMU must exist on the MATLAB® path.

To specify an FMU name, enter the name in the FMU name text box.

When you click OK, the block creates an /slprj/_fmu/unique_ID folder with the unpacked files and the file hierarchy intact.

Dependencies

When you specify an FMU name, the block dialog updates to contain four tabs:

  • Parameters

  • Simulation

  • Input Bus

  • Output Bus

Programmatic Use

Block Parameter: FMUName
Type: character vector
Values: name of an FMU, with or without file extension
Default: ' '

Parameters

This tab lists parameters defined in the FMU.

  • To display only the parameters you are interested in, type a search string in the filter field. This string can match the parameter name or text in the description.

  • In the parameter table, you can change the value of the parameter in the Value field.

Simulation

Select this check box to enable the specification of a tolerance value to the FMU.​ Otherwise, clear this check box.

Dependencies

This parameter is applicable only if your FMU version or mode supports tolerance values.

Programmatic Use

Block Parameter: FMUIsToleranceUsed
Type: character vector
Values: on | off
Default: 'off'

FMU relative tolerance value (%), specified as a scalar.​

Dependencies

This parameter is applicable only if your FMU version or mode supports tolerance values.

Programmatic Use

Block Parameter: FMUToleranceValue
Type: character vector
Values: 1E-3 | scalar
Default: '1E-3'

Communication step size during simulation, specified as a scalar.​ Specify the time interval between simulation time instants for the block. For more information, see Timing Considerations.

In most cases, to prevent unexpected behavior, set this value to a positive value. To inherit the sample time from the driving block or the model solver, set this parameter to -1. For more information, see Specify Sample Time.

The block supports different types of sample time,​ including continuous,​ discrete,​ and Inherited. However,​ common co-simulation FMUs support only periodic discrete sample times without offset (such as positive scalar).

Dependencies

This parameter is applicable only in Co-Simulation mode.

Programmatic Use

Block Parameter: FMUSampleTime
Type: character vector
Values: scalar
Default: '-1'

To enable the display of FMU debug logging, select this check box. Otherwise, clear this check box.

Programmatic Use

Block Parameter: FMUDebugLogging
Type: 1xN cell array of character vectors
Values: on | off
Default: 'off'

Filter debug logs by type, specified by selecting these check boxes:

  • OK

  • Warning

  • Discard

  • Error

  • Fatal

  • Pending

Programmatic Use

Block Parameter: FMUDebugLoggingFilter
Type: character vector
Values: OK | Warning | Discard | Error | Fatal | Pending
Default: 'OK' | 'Warning' | 'Discard' | 'Error' | 'Fatal' | 'Pending'

Direct debug logs, specified as:

  • File — Stream to slprj/_fmu/_logs_modelname/modelname_FMUblockname.txt​.

  • Display — Stream to the MATLAB Command Window.

Dependencies

Setting this parameter to File enables the Open FMU Log File... link.

Programmatic Use

Block Parameter: FMUDebugLoggingRedirect
Type: character vector
Values: File | Display
Default: 'File'

Input

This tab lists input variables specified in the FMU modelDescription.xml.

Specify the variable for a structured input port.

To filter the variable by name, type the variable name in the text box.

The variables table lists the variables and their values for nodes at the top of the hierarchy and their children, many of which you can edit on this tab.

  • Name — Variable name. This is not editable.

  • Visibility — Select this check box to enable an input port on the block for the variable. Clear this check box to remove a port.

    Selecting this check box at a top-level node makes the child nodes visible as one port for the block.

    Note

    When you click Apply, the number of block ports change. Remember to add or remove connections accordingly.

  • Start — Add a start value defined in modelDescription.xml. You cannot:

    • Change the start value when the corresponding input port is visible.

    • Add start values to nonleaf nodes. (You can edit start values only for leaf nodes.)

  • Bus object name — Set the bus object variable that corresponds to the port. By default, the variable uses the structured variable name defined in modelDescription.xml. To create a new variable in the workspace, use fmudialog.createBusType.

Changing any variable values enables the Restore output to default settings button, which you can click to restore original settings.

Output

This tab lists output variables specified in the FMU modelDescription.xml.

Specify the variable for a structured output port.

To filter the variable by name, type the variable name in the text box.

The variables table lists the variables and their values for nodes at the top of the hierarchy and their children, many of which you can edit on this tab.

  • Name — Variable name. This is not editable.

  • Visibility — Select this check box to enable an output port on the block for the variable. Clear this check box to remove a port. If internal variables exist in this FMU, you can enable or disable visibility for individual internal variables. If an internal variable is selected, it creates an additional output port.

    Selecting this check box at a top-level node makes the child nodes visible as one port for the block.

    Note

    When you click Apply, the number of block ports change. Remember to add or remove connections accordingly.

  • Start — Add a start value defined in modelDescription.xml. You cannot change or add a start value for an output variable.

  • Bus object name — Set the bus object variable that corresponds to the port. By default, the variable uses the structured variable name defined in modelDescription.xml. To create a new variable in the workspace, use fmudialog.createBusType.

Changing any variable values enables the Restore output to default settings button, which you can click to restore original settings.

Block Characteristics

Data Types

string

Direct Feedthrough

no

Zero-Crossing Detection

no

Introduced in R2017b