Patent ID: 6343331
Filing Date: 2002-01-29
Classification: G06F,H04B,H04L

Abstract:
A local communication system comprising:a plurality of stations in which one station is designated a master station and the other stations designated as slave stations, the plurality of stations being interconnected by point-to-point links in a ring network for the exchange of data messages, wherein each station is arranged, in a start-up procedure, to recognise a signal received from a preceding station in the ring and to transmit a corresponding signal to a following station in the ring, and wherein, in the event that recognition is not obtained within a predetermined time, a start fault procedure is implemented, the start fault procedure implemented by each station comprising: configuring each slave station to act as temporary system master, generating its own output signal for recognition by the following station in the ring; in the event that recognition of a signal from the preceding station in the ring is still not achieved, generating a position message indicating a default ring position; in the event that recognition of a signal from the preceding station is obtained, reverting to slave status, receiving said position message and transmitting to the following station a modified position message so as to indicate an incremented ring position; recording in at least one designated diagnostic station, an indication of the ring position indicated by a position message received by the designated diagnostic station, as an indication of fault position for diagnostic purposes.