Create and Activate Variant Configurations - MATLAB & Simulink (original) (raw)

Note

This functionality requires Variant Manager for Simulink®.

A model might contain several variant blocks or variant parameters, each with many variant choices. A variant configuration is used to represent a combination of such variant choices across the model hierarchy. For example, in a system with a plant and a controller, a linear controller with an internal plant with no noise and a nonlinear controller with an external low fidelity plant represent two different configurations of the system.

You can use Variant Manager to create and manage variant configurations for a model. Variant Manager defines a variant configuration as a set of variant control variables and their values that can activate a specific variation in the model hierarchy. For more information on variant configurations, see Variant Configurations. For an overview of Variant Manager, see Variant Manager for Simulink.

Steps to Create Variant Configurations

You can create multiple named variant configurations for a model or you can create variant control variables in the data sources used by the model to use as a temporary variant configuration for the model.

This image shows the high-level workflow to create and save a new named variant configuration for a model.

Workflow to create a named variant configuration

Open Variant Manager

Open the model for which you want to create new variant configurations. Here, open theslexVariantManagement model using the following command.

openExample('simulink_variants/VariantConfigurationObjectForAModelRefPageExample'); open_system('slexVariantManagement');

On the Modeling tab, open the Design section and click Variant Manager.

Configurations Tab in Variant Manager

View the Configurations tab in Variant Manager.

Variant configurations pane in Variant Manager

Add New Variant Configuration

  1. To create a temporary variant configuration, click the entry corresponding to the storage location used by the model in the Configurations tab, for example, topdata.sldd.
  2. To add a new named variant configuration, click the Add variant configuration button. A new row is added to the table of named configurations. Type a name for this configuration in the box.

Variant configurations pane in Variant Manager with a new configuration named Configuration

Add, Import, or Export Control Variables in Variant Configuration

  1. In the Configurations tab, scroll down to see theControl Variables section. The section shows the name of the currently selected variant configuration.
  2. In this section, click the Import control variables across model hierarchy button to import any existing control variables used by the model to the variant configuration.
  3. To import variant control variables of type Simulink.VariantControl defined in the base workspace or a data dictionary linked to the model even if the variant control is not yet used by the model, click the down arrow on the Import control variables across model hierarchy button and select Import control variables from model data source.
  4. To add a new control variable to the variant configuration, click the Add control variable button . By default, this operation adds a new control variable of type Simulink.VariantControl with a normal MATLAB® variable as its value to the control variables table. To add other types of control variables, click the down arrow on the button. You can update the values in this table. For a list of actions that you can perform from the control variables table, see Edit Control Variables in Variant Configuration.
  5. To export the control variables to the data sources where they are stored, click the Export control variables to workspace(s) button .
  6. You can use the Description section to provide an optional description for the configuration.

Control variables section in Configurations tab

Edit Control Variables in Variant Configuration

You can perform these operations from the Control Variables section.

Operation Action
Add new control variables to a configuration Click the Add control variable button .The default type of a new control variable isSimulink.VariantControl, with a normal MATLAB variable as its value.You can also add these types of variables. To see all the options, click the down arrow on the button. Normal MATLAB variableSimulink.ParameterAUTOSAR.ParameterUser-defined data class that derives fromSimulink.Parameter
Import variant control variables used by the model hierarchy Click the Import control variables across model hierarchy button.NoteControl variables from blocks in Label mode are not imported as they are not variant control variables.
Import variant control variables of type Simulink.VariantControl from the base workspace or a data dictionary linked to the model even if the variant control is not yet used by the model Click the down arrow on the Import control variables across model hierarchy button. Select Import control variables from model data source.
Export control variables to the data sources where they are stored. Click the Export control variables to workspace(s) button.
Sort the rows based on each column Click the column names, such as Name,Value, VAT, orSource, in the header row to sort the table based on the values in that column.
Show or hide the usage of control variables in a configuration To find the usage of a particular variant control variable in a variant configuration, select the variable in the control variables table and click the Show usage of selected control variables button. The rows that contain the variable appear highlighted in the model hierarchy table.For variant parameters in the model hierarchy, the control variable usage is shown in theVariant Parameters tab withView set to Choice per row. _(since R2024a)_To hide the usage of a variant control variable, click the Hide usage of selected control variables button .Alternatively, right-click the variable in the control variables table and select Show usage or Hide usage.TipYou can navigate the model hierarchy to understand the usage of control variables in a configuration. After you activate a variant configuration, enable Show usage for the required variant control variables. Now select variable usage from theNavigate list in the model hierarchy table. Use the arrow key to step through the model hierarchy rows that use those variables.
Change the data type of control variables in a configuration Click the down arrow in the Convert toSimulink.VariantControl button to see the options for conversion.You can convert the control variables to any of these types: Simulink.VariantControl with aSimulink.Parameter object as its valueSimulink.VariantControl with a normal MATLAB variable as its valueSimulink.VariantControl with a user-defined type that inherits from Simulink.Parameter as its valueSimulink.ParameterAUTOSAR.ParameterNormal MATLAB variableFor an example that shows the use of different types of variant control variables and their purpose, see Use Variant Control Variables in Variant Blocks.
Edit Simulink.Parameter orAUTOSAR.Parameter control variables Use the Edit Simulink.Parameter orAUTOSAR.Parameter control variable button .To specify Simulink.Parameter control variable as an expression, set the Value property of the parameter object by using an equal sign (=) followed by a mathematical expression. For example, enter = A + B.
Filter the table based on type of control variables Use the Filter based on variable types button.
Filter content in the table Enter the search term in the Filter text box. Press Esc to clear the text box.

Set Up Variant Configurations for Referenced Components

Your model may consist of referenced models that have predefined variant configurations. The variant configurations for a top-level model must also define the variant control variables used by any referenced components in the model hierarchy, such as referenced models. This approach helps to maintain a single consistent definition for a variant control across the hierarchy.

If the referenced component has existing named variant configurations of its own, you can use them to set up the corresponding variant control variables in the top-level model configuration. You can use the Component Configurations view in Variant Manager to select the referenced component configurations to be used for the initialization. For steps to use the Component Configurations view, see Compose Variant Configurations and Constraints for Top Model Using Referenced Component Configurations.

Define Constraints for Variant Configurations

A constraint is a user-defined check that you can use to prevent invalid variant combinations in a model. You can define model-wide constraints that must be satisfied by all variant configurations created for the model. A model-wide constraint is represented as a condition expression created using variant control variables, referenced component configurations (since R2025a), or both. The expression must evaluate to true to satisfy the constraint. When you activate a variant configuration, Variant Manager validates the configuration against the applicable constraints.

Note

Variant Manager constraints are also validated when you compile the model for an active configuration. However, these constraints are not validated post compilation, for example, at startup variant activation time.

  1. Click the Constraints tab in the Variant Manager window. TheConstraints table lists any existing constraints created for the model.
  2. To add a new constraint, click the Add constraint button. A new row is added.
  3. Enter a name for the constraint in the box.
  4. In the Constraint Definition section, in theCondition box, enter the boolean condition expression defined in terms of variant control variables. The condition must evaluate to true to satisfy the constraint.
  5. In the Description box, enter an optional description for the constraint.

Constraints tab in Variant Manager

For more information on defining constraints using component configurations, see Compose Variant Configurations and Constraints for Top Model Using Referenced Component Configurations.

Tip

You can change the layout of the Variant Manager window to keep theConfigurations and Constraints panes next to each other. This layout allows you to refer the Control Variables section when defining constraints. To move a pane, click at the top of the pane and drag.

Save Variant Configurations

You can use a variant configuration object of typeSimulink.VariantConfigurationData to store all named variant configurations and constraints for a model. You can define the object in the base workspace or in theConfigurations section of a data dictionary. If the model is not yet associated with a variant configuration object, Variant Manager helps you to setup a new variant configuration data object.

  1. Type a name for the variant configuration data object in theSimulink.VariantConfigurationData text box in the Variant Manager toolstrip.
  2. To export the variant configuration data object to the base workspace or Simulink data dictionary used by the model, click Apply changes. This action also associates the object with the model.
  3. To reload the object from the base workspace or data dictionary used by the model, click Reload object. This allows you to revert the changes that are not yet exported to the data sources used by the model.
    When you export the variant control variables in a variant configuration or when you activate a variant configuration, the control variables are pushed to the data sources where the variables are stored. Reloading the variant configuration object from Variant Manager does not revert these changes.
  4. To disassociate the variant configuration data object from the model, set theSimulink.VariantConfigurationData box to empty and clickApply changes.
  5. To export the variant configuration data object to a MAT file or MATLAB script, click Export to file.
    If the variant configuration data object is defined in the base workspace, this step allows you to save the object and reuse it later by importing it into Variant Manager. However, if the object is defined in a data dictionary, you need not export the object to a MAT file or MATLAB script. Instead, you must save changes to the data dictionary.
  6. To load the variant configuration data object saved in a file into Variant Manager, click Import from file.

Note

After you click Apply changes, save the model to save the changes made from Variant Manager.

Validate and Activate Variant Configuration

To activate a model programmatically, see Simulink.VariantManager.activateModel.

For information on how the activation process differs from model compilation (update diagram), see Differences Between Variant Manager Activation and Update Diagram Process.

Use Model Compilation Information in Variant Manager

Since R2024b

You can obtain model compilation information in Variant Manager to produce more accurate results for user workflows such as importing control variables to a configuration, activation, and identifying variant parameters used by the model hierarchy. Click Update Model in the Variant Manager toolstrip or use the Simulink.VariantManager.updateModel function. For more information, see Obtain and Use Model Compilation Information in Variant Manager.

Apply Variant Configuration on Model

Once you have saved the validated variant configuration to a file, you might want to simulate your model for the configuration at a later time.

To programmatically apply a configuration on your model before compiling or simulating the model, use the Simulink.VariantManager.applyConfiguration method.

See Also

Simulink.VariantConfigurationData | Simulink.VariantConfigurationAnalysis

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