Why Use a Mask?

Masks can provide interface customization, logic encapsulation, and data hiding. For example, although defining a subsystem simplifies a model's graphical appearance, the simplification does not provide a user interface that is specific to the subsystem. The lack of a subsystem-specific interface has several possible disadvantages, including:

• The subsystem's icon is generic: it does not indicate the meaning of the subsystem, and cannot change to provide information about parameter settings in the subsystem.

• The subsystem parameters that need to be changed to control behavior may be distributed among many subsystem blocks, making the parameters hard to find.

• The parameter names in the blocks comprising the subsystem reflect only the generic purpose of each block, rather than the parameter's purpose in the context of the model.

• Making any change to the subsystem requires exposing its complete contents in an editor, which makes the subsystem vulnerable to unintended changes.

• Because the subsystem has no separate parameters dialog box, no Block Help information is available for the subsystem, as it would be for a built-in block.

Masking a subsystem can address all of these problems. A subsystem mask can:

• Display a meaningful icon that updates dynamically and reflects values within the subsystem.

• Define customized user-settable parameters whose names reflect the purpose of the subsystem.

• Provide a parameters dialog box that gives access only to parameters that should be exposed.

• Shows customized Block Help and Online Help information that is specific to the subsystem.

The mask thereby encapsulates the subsystem under an interface that reflects the subsystem as the user sees it, as distinct from the subsystem's architecture, and provides the look and feel of a built-in Simulink block. Similar advantages apply to masks on Model blocks and S-Function blocks.

What Are Masks?

Masked Subsystem Example

Related Products & Applications

• Simulink
• Control Design
• Signal Processing & Communications
• Model-Based Design
• Physical Modeling
• Verification & Validation

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