A model for asynchronous control networks

A control network is viewed as a set of interconnected circuits, each performing an asynchronous sequential function. The reaction time of every circuit and the size of the delays present on the interconnection wires are considered to be nonbounded but finite quantities. An abstract model is proposed which provides a useful tool for the analysis and synthesis of control networks. Some network properties are defined precisely, i. e. persistence (no loss of signal); liveness (no hang-ups in any part of the network; activity (the network as a whole never hangs-up); determinacy (the same signals are always generated independently of the speed of the circuits and the size of the delays). The problem of the physical implementation of such circuits in a network is discussed.