This paper presents a new model for the specification of communicating X-machine systems (CXMS). In previous papers, systems of X-machines have been implemented in two ways: using an unique X-machine which simulates the concurrent behaviour of several processes [1], or using several X-machines which communicate through asynchronous channels [2]. This article introduces an X-machine system for which the communication between components is done through synchronous channels. The model supposes that each X-machine has a local memory, an input and an output tape. The X-machines act simultaneously. The states of each component of the system are partitioned into processing and communicating states. Passing messages between the X-machines involves only communicating states. It is shown that, taking advantage of the behaviour of X-machines, communication using channels may be implemented, thus providing a synchronous message passing.

communicating X-machine systems, concurrent processes, communication using channels