Real-time mode-machines

  • Stephen Paynter
Selected Presentations State Charts
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1135)


Modes are a natural abstract way of structuring the behaviour of complex systems. The different ways in which a system can operate are associated with different modes, and transitions link modes to form mode-machines. However, mode-machines need a precise semantics if they are to be used for specifying the behaviour of critical systems. This paper analyses the possible relationships between modes and states. A number of concurrent systems described using MASCOT are considered, and their mode-based behaviour is used to motivate the semantics of a new real-time mode-machine notation, RTMMs. It is argued that RTMMs should not behave like abstract state-machines. A list of concurrent transactions is associated with each RTMM mode, and a notation is given for specifying their timing properties. RTMM transactions need not terminate when the central mode-controller switches mode, thus capturing the asynchronous way in which large systems respond to mode changes. RTMMs are given a proof-theoretic semantics using many-sorted logic, extended with the RTL occurrence relation, Θ.


Execution Time Mode Change Concurrent System Concurrent Design Concurrent Transaction 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • Stephen Paynter
    • 1
  1. 1.British Aerospace Dynamics Ltd.FiltonUK

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