Patent ID: 6184778
Filing Date: 2001-02-06
Classification: H04L

Abstract:
A communications network system including a plurality of node devices distributed at a plurality of positions and transmission lines for connecting the plurality of no node devices in a ring-shaped configuration, one of the plurality of node devices being set as a master station to operate the system, wherein each node device comprises:detection means for detecting a trouble by determining that a monitor signal from the master station was not received;inquiring means for making an inquiry in an asynchronous transmission mode among the respective node devices when the detection means detects that the trouble has occurred with the master station;confirming means for confirming that there is no node device having a higher priority than itself based on an inquired result by the inquiring means; andmaster station setting means for setting the node device, if the confirming means confirmed that there is no node device having a higher priority than itself, as a substitute master station in place of the troubled master station.