Patent ID: 6282669
Filing Date: 2001-08-28
Classification: H04L

Abstract:
A redundancy method for Ethernet communication between a plurality of nodes constituting a distributed control system, comprising the steps of:connecting each node of said plurality of nodes to each other in a duplex state through a first and a second Ethernet communication line, wherein said first Ethernet communication line and said second Ethernet communication line are independent of each other;transmitting identical data from a node on a transmission side through each of said first and said second Ethernet communication lines;receiving said identical data at a node on a receiving side through each of said first and said second Ethernet communication lines; andselecting which one of the identical data received at a node on said receiving side from said node on said transmission side through said first and said second Ethernet communication lines has arrived first as reception data;adding a data identifier to each of said identical data for identifying data to be transmitted as data transmitted on one of said first Ethernet communication line and said second Ethernet communication line, and said selecting step further comprises checking on the basis of said data identifier added to each of said identical data transmitted from said node on said transmission side to said node on said receiving side whether said data from said node on said transmission side is data that has arrived at said node on said receiving side first through one of said first Ethernet communication line and said second Ethernet communication line.