Variant Connector

Remove or disconnect physical components from network

Since R2020b

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Libraries:
Simscape / Utilities

Description

The Variant Connector block lets you define variant choices in a physical network. Variant choices allow you to exclude some components from simulation without physically removing the components from the physical network. The components to be disconnected must be connected to the port associated with condition data. During simulation, the variant condition is propagated to all the connected components within the physical network. If the variant control associated with the block evaluates to true, all the components that are connected to the block become active. If the variant control evaluates to false, all the components connected to the block become inactive.

Examples

Variant Leaf Region in Mechanical System

Simulate the displacement of velocity sources and mass by using the leaf type of the Variant Connector block. The leaf Variant Connector block forms a leaf region that allows you to vary the displacement during simulation.

• Open Model

Variant Bounded Region in Electrical Circuit

Activate or deactivate the flow of a current to a set of components in an electrical circuit by using the primary and nonprimary type Variant Connector blocks. The primary and nonprimary Variant Connector blocks form a bounded region that allows you to vary the electrical circuit during simulation.

• Open Model

Variant Connector Block with Simscape Bus Block

Use Variant Connector blocks with the Simscape Bus block.

• Open Model

Mask Workspace Variable in Variant Connector Block

Use a mask workspace variable as a variant control variable in a Variant Connector block.

• Open Model

Limitations

• The Variant Connector block does not propagate the variant condition across the boundary between the Simscape™ physical network and the Simulink^® blocks connected to it. In other words, if a block has both conserving ports and Simulink signal ports, such as a Simulink-PS Converter, a PS-Simulink Converter block, or a Subsystem block, the Variant Connector block stops propagating the variant condition at the boundary of that block. The condition is not propagated to any of its connected blocks. For more information, see Variant Condition Propagation From Variant Connector Block to Subsystem Block.

Ports

Conserving

Port_1 — Condition port

untyped conserving port

This port is located on the left side of the block and is labeled with a rectangle. During simulation, if the variant choice associated with the block evaluates to true, all the components that are connected to this port become active. If the variant choice associated with the block evaluates to false, all the components connected to this port become inactive.

By default, this port is untyped. You define the type of this port by connecting it to a conserving port of another block, components in the network, or a Simscape Bus port.

Port_2 — Connection port

untyped conserving port

Conserving connection port. By default, this port is untyped.

You define the type of the port by connecting it to a conserving port of another block, components in the network, or a Simscape Bus port.

Parameters

Connector Type — Type of connector block

Leaf (default) | Primary | Nonprimary

Select a connector type based on the components to deactivate.

• Leaf: If you want to deactivate all the components connected to the block, set Connector Type to Leaf.

  For example, in this model, the variant condition associated with the Variant Connector block, ConneBlk1, is A == 1. The variant condition associated with the Variant Connector block, ConneBlk2, is B == 1. During simulation, when A == 1 evaluates to true and B == 1 evaluates to false, all the components connected to ConneBlk1 block become active, and all the components connected to ConneBlk2 block become inactive.

  

• Primary and Nonprimary: If you want to restrict the propagation of the variant condition to a set of components, create a Bounded region by using primary and nonprimary connector blocks. To form a bounded region, the primary and nonprimary connector blocks must have the same Connector Tag property.

  When you set Connector Type to Primary or Nonprimary, the connector tag of the block is displayed on the block icon. The connector tag of the primary connector block is displayed with double lines and the connector tag of the nonprimary connector block is displayed with single lines.

  A primary Variant Connector block and all nonprimary Variant Connector blocks with the same Connector Tag as the primary block constitute a set of related blocks.

  You can select a primary or nonprimary Variant Connector block to highlight all related Variant Connector blocks.

  The blocks that are highlighted in the model canvas are also highlighted in the miniature map.

  To show a related block in an open diagram, pause on the ellipsis that appears after selection. Then, select Related Blocks from the action bar. When multiple blocks correspond to the selected block, a list of related blocks opens. You can filter the list of related blocks by entering a search term in the text box. After you select a related block from the list, window focus goes to the open diagram or new tab that shows the related block.

Connector Tag — Unique identifier of bounded region

A (default) | valid MATLAB^® identifier that starts with a letter, contains no spaces or special characters and is at most 63 characters long

Specify an identifier in the Connector Tag parameter. The primary and nonprimary connector blocks with the same tag form a Bounded region.

Dependencies

To enable this parameter, set Connector Type to Primary or Nonprimary.

Variant control expression — Variant controls available in global workspace

true (default) | boolean condition expression

Displays the variant controls available in the global workspace. The variant control can be a Boolean condition expression containing a regular MATLAB variable or a Simulink.VariantExpression object representing a Boolean condition expression.

To edit a variant name, double-click a Variant control expression cell and type in the variant control expression. Click Apply after you edit a variant control name.

When the variant control associated with the block evaluates to true, all the components connected to the block become active.

Programmatic Use

Block Parameter: VariantControls

Type: cell array of character vectors

Value: Variant control that is associated with the Variant choice

Default: 'Variant'

Condition (read-only) — Condition for Variant controls

no default

This read-only field is based on the condition for the associated Variant control in the global workspace. Create or change a Variant condition in the Simulink.VariantExpression parameter dialog box or in the global workspace.

For more information, Simulink.VariantExpression.

Show variant condition on block — Display variant condition on block icon

off (default) | on

Select Show variant condition on block to display the variant condition associated with the block on the block icon.

Open block in Variant Manager — Open Variant Manager window

no default

Click Open block in Variant Manager to open the Variant Manager.

More About

Bounded region

A bounded region is a part of a model located between one Variant Connector block where Connector type is set to Primary and any number of Variant Connector blocks where Connector type is set to Nonprimary. All of the blocks in a bounded region must use the same Connector tag parameter.

For example, this model has two bounded regions. The first region has one primary and two nonprimary Variant Connector blocks. These blocks are connected to each other by the connector tag Region1 and the associated variant condition A == 1. The second region has one primary and one nonprimary Variant Connector block. These blocks are connected to each other by the connector tag Region2 and the associated variant condition B == 1. During simulation, when A == 1 evaluates to true, the components in the first region become active. When B == 1 evaluates to false, the components in the second region become inactive.

When you create a bounded region, ensure that:

• Each region has only one primary Variant Connector block. Each primary Variant Connector block is connected to at least one nonprimary Variant Connector block. All Variant Connector blocks must be connected using the port associated with condition information.

• All the primary and nonprimary blocks are at the same level of model hierarchy.

• Each region has a unique connector tag in a model hierarchy.

  

• The region is bounded and has no external connections.

  

• There are no Variant Connector blocks where the Condition type is set to Leaf inside the bounded region.

• No bounded regions overlap each other.

  

Variant Condition Propagation From Variant Connector Block to Subsystem Block

The Variant Connector block does not propagate the variant condition across the boundary between the Simscape physical network and the Simulink blocks connected to it. In other words, if a block has both conserving ports and Simulink signal ports, such as a Simulink-PS Converter, a PS-Simulink Converter block, or a Subsystem block, the Variant Connector block stops propagating the variant condition at the boundary of that block. The condition is not propagated to any of its connected blocks.

For example, in this model, as the Subsystem block has both conserving ports and Simulink signal ports, the Variant Connector block does not propagate the variant condition to the Subsystem block.

However, if the Subsystem has only conserving ports, the Variant Connector block propagates the variant condition to the Subsystem block and to the blocks that are connected to the Subsystem block. However, the propagation stops at the PS-Simulink Converter block because it has both conserving ports and Simulink signal ports.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

Usage notes and limitations:

The code is generated only for active blocks in the model. Inactive blocks do not participate in code generation.

Version History

Introduced in R2020b