Communicating Reactive State Machines: Design, Model and Implementation

Abstract This paper proposes a language, called Communicating Reactive State Machines (CRSM), useful for describing behaviors of real-time distributed controllers. The characteristic features of this language are that it has a pictorial syntax, a precise formal semantics and an efficient implementation. CRSM is based on Argos, a language proposed for centralized real-time controllers. Argos is extended by including a primitive for communication between Argos programs. This communication primitive is based upon the communication primitive of CSP. A precise mathematical model, called communicating boolean automata (CBA) based upon the boolean automata model of Argos is developed. A number of operations over CBA have been defined to model the constructs of CRSM and a notion of bisimulation equivalence is also defined. CBA would form the basis for automatic verification of CRSM. An outline of an implementation of CRSM is also given.