A synchronous and asynchronous mode algorithm in an industrial LAN based distributed communication system

We give ideas that contribute to a clear description, specification and modelling of some communication protocols for distributed communication systems based on industrial LANs. In these systems problems turn up with time management, coexistence of different intelligent devices that work in real time, compatibility of synchronous and asynchronous operation modes, concurrent processes and bus and ring topology LANs. The algorithm specification and formal modelling that handle these problems have been made with the formal description technique (FDT) ESTELLE.