UML Protocol State Machine Diagrams

UML protocol state machine diagram in Altova UModel

UModel Protocol State Machine Diagram Features:

  • Toolbar for quick access to protocol state machine diagram elements
  • Entry helpers and fast editing buttons
  • Right-click context menu activates anywhere in diagram
  • Cascading styles for colors, fonts, line size, and more
  • Customizable alignment grid
  • Elements can be assigned to diagram layers and selectively viewed or hidden
  • Unlimited undo/redo encourages exploring new ideas

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UML Protocol State Machine Diagrams Display a Sequence of Events without Specific Behaviors

UModel® 2017 supports protocol state machine diagrams as a unique diagram type, with a specialized diagram toolbar.

UML Protocol state machine diagrams are a subset of state machine diagrams that display a sequence of events an object responds to, without having to show the specific behavior. Protocol state machines are most often used to describe complex protocols, such as database access through a specific interface, or communication protocols such as TCP/IP.

Although you can create protocol state machine diagrams using existing state diagram elements, state diagram history elements are not employed, and other elements imply slightly different syntax. For instance, transitions between states can have pre- or post- conditions that define what must be true for a transition to another state to occur, and what the resulting state must be after the transition has taken place. UModel shows transition pre- and post-conditions in the Properties helper window. You can enter them directly in your diagram, or in the Properties window.

Because of the special features of protocol state machine diagrams, to avoid confusion when you share models with other project stakeholders, and to help enforce correct UML syntax, it is appropriate to treat protocol state machines separately.

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