Abstract: The invention relates to an object-oriented software system having replicated objects and which makes it possible to control a monitoring/control installation of redundant architecture and comprising at least one first processor (1) and one second processor (1'). The software system (2) comprises software objects (3) intercommunicating by means of messages via a dynamic object messaging mechanism. A replica (2') of the software system (2) is contained in the second processor (1'). Certain objects (3) of the software system (2) are marked and the dynamic object messaging mechanism (5) includes monitoring means (51) for identifying an object message addressed to a marked object, and means (52) for passing on the contents of the object message, in the form of a network message, to the second processor (1'). In response to the network message, the dynamic object messaging mechanism (5') in the second processor (1') activates the replica (3') of the marked object (3).

Abstract: A method of transmitting data between a set of data processing nodes interconnected by a communications network. Each node broadcasts data to the other nodes by causing a train of such data to travel over the network around a looped circuit or "ring" passing through each of said nodes, each node in the ring having a predecessor and a successor. A counter is provided in the data train, and on receiving a data train sent by its predecessor, each node recovers the counter from the received data train, increments the counter, and dispatches to its successor a new data train including the counter as incremented. It also stores the new data train with the incremented counter in its memory so that it is possible to implement a simple fault recovery procedure in the event of one of the nodes becoming faulty.