Table 1: The formal expression of system’s connections.

Connection types between componentsGraphical representationDescription

Mechanical connection
()
Mechanical connection between components is unidirectional
Mechanical connection between components is bidirectional

Electrical connection
()
Electrical connection between components is unidirectional
Electrical connection between components is bidirectional

Information link
()
Information link between components is unidirectional
Information link between components is bidirectional