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Internal Block Diagrams

An Internal Block diagram (IBD) captures the internal structure of a Block element, in terms of its properties (Ports and Parts) and the connections between those properties. The IBD is an instance of the Block element, and the Block is the classifier for the IBD.

The elements in the IBD are enclosed in a frame representing the parent Block element. The name of the parent Block is displayed in both the diagram title and in the frame label; in the example diagram, the Block is called 'PowerSubsystem' and its IBD is called 'CAN Bus Description'.

If necessary you can create more than one IBD for a Block. As an IBD is its Block's composite child diagram, if you have more than one IBD you specify which one is the active child of the Block.

Whilst the IBD defines the structure of a Block, the broader context and usage of that Block is defined in a Block Definition diagram.

IBD Ports

Ports on an IBD can be set to show compartments containing the features and characteristics of the element, such as Tagged Values, Constraints and Attributes. To set which compartments to show, right-click on the Port and select the 'Compartment Visibility' option (for full details, see the Feature Visibility Help topic).

To show the compartments, right-click on the Port and select the 'Advanced | Show Compartments' option.

The Ports in the IBD can also be set to show the direction of flow into and out of the Block (by associating them on the Block with a Flow Property). See the Show Direction on SysML Ports Help topic.

Model Elements

The Model Elements for Internal Block diagrams are available through the 'SysML Block Internal' pages of the Diagram Toolbox.

The elements that you can use in Internal Block diagrams are:

  • Property
  • Connector Property
  • Distributed Property
  • Flow Property
  • Participant Property
  • Directed Feature
  • Adjunct Property
  • Bound Reference
  • End Path Multiplicity
  • Classifier Behavior Property
  • Signal
  • Port

The connectors that you can use in Internal Block diagrams are:

  • Item Flow
  • Connector
  • Binding Connector
  • Dependency

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