Internal block diagram

Internal Block Diagrams (IDD)^[1]: 52 are a static representation of the internal structure of blocks. Where the BDDs represent a black box view of the system, the IBDs represent a white box view. It details how the parts of a block are interconnected through ports and connectors, providing a clear visualization of the system's internal composition and interactions.^[2]

Example IBD showing internal structure of a subsystem and the ports to other subsystems and external systems

Elements

Parts

The IBD represents the internal structure of a block, and the internal components of the block are represented by parts. These parts may have a multiplicity defined, indicating the number of instances of the component that may exist in the block.^[3]

Reference Properties

An IBD may contain external elements that the block does not own. These are represented by rectangles with dashed borders.^[3]

Ports ^{[1]: 75 [3]}

Ports specify interaction points between parts. In an IBD, they are represented by small squares on the edges of a part. There are two types of ports:

• Standard ports define provided and required interfaces.
• Flow ports specify the flow of objects between parts.

Connectors

Connectors are lines that connect ports and represent communication paths between the parts. Information, energy, and materials flow over these connectors.^[1]: 75

When to use