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General


Editing Functions

The MSC Editor is the graphical tool that you use to create, edit, print and store Message Sequence Charts. The MSC Editor provides, among other things, the facility of including MSCs into SDL systems.

The basic editing functionality that the MSC Editor provides can be summarized as:

Tracing a Simulation

You can also use the MSC Editor as a graphical trace tool, which enables the automatic generation of an MSC from a simulation. The results of the simulation will be presented in an MSC Editor window, in which each event of interest will be appended to the chart in order to build up a chart which reflects the history of the simulation. The results of a simulation can be saved in MSC/PR form and re-read by the MSC Editor.

The commands that start up the logging of MSC events, set up the scope of trace, stop the logging of events, and so on, are given to the Simulator. See Simulating a System.

Validating a System

An MSC can be used as a means to express the requirements on an SDL system. With the MSC Editor and the SDL Explorer, a powerful validation environment is provided. The basic idea is to draw an MSC using the MSC Editor and then use the Explorer to check if there is a possible execution path for the SDL system that satisfies the MSC.

The commands that validate a system are given to the Explorer. See Validating a System.

Tracing user-defined events

The MSC editor also contains an API that enables any user or tool vendor to make interactive traces of events of their own choice (custom trace). Please see the header file <product install dir>/include/msctrace/msctrace.h for further details on this API.

Supported MSC Formats

The MSC Editor supports reading MSCs stored in either:

By default, the MSC Editor stores diagrams in the MSC/GR format, but it can also generate MSC/PR for a diagram.

MSC/PR files can be expressed in two forms, event-oriented1 or instance-oriented2. See the Z.120 recommendation for more information on these two alternative formats.

1

Event oriented MSC/PR describes the MSC using the order in which the events occur, i.e. starting with the top of the diagram and downwards, providing the feeling of a global event order.

2

Instance oriented MSC/PR describes the MSC on an instance by instance basis. The feeling of a global event order within the MSC is lost.


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