Message sequence chart: Difference between revisions

Revision as of 14:04, 28 July 2014

Revision as of 15:27, 28 July 2014

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Latest version has been published in February 2011.

==Symbols in MSC==

The existing symbols are:

* MSC head, lifeline, and end: a vertical line with a box at the top, and a box or a cross at the bottom.

* Instance creation: horizontal dashed arrow to the newly created instance.[[File:Dynamic Process Creation in a Message Sequence Chart.png|thumb|Dynamic process creation in an MSC]]

* Message exchange: horizontal arrow.

* Control flow: horizontal arrow with the 'call' prefix, dashed arrow for reply symbol, method and suspension symbols in between. [[File:MSC CallOperation.png|thumb|Call operation in an MSC]]

* Timers: start, cancel, time out.

* Time interval: relative and absolute with a dashed vertical arrow. [[File:MSC TimeConstraint.png|thumb|Time constraint in an MSC]]

* Conditions: usually used to represent a state of the underlying state machine.

* Action: a box.

* In-line expressions: alternative composition, sequential composition, exception, optional region, parallel composition, iteration (loop).

* Reference: reference to another MSC. [[File:MSC Reference.png|thumb|MSC Reference in an MSC]]

* Data concept: The user can use any data concept, if binding is undefined the default data concept is the one from [[Specification and Description Language|SDL]] as defined in Z.121 recommendation.

* Coregion: a double dashed instance line to describe unordered events.

==Symbol extensions==

* [[SDL-RT]] has introduced:

** a semaphore instance representation. [[File:SDL-RT MSC Semaphore.png|thumb|SDL-RT Semaphore extension to MSC]]

** a save symbol to save messages.

==Comparison to UML==