| 摘要 |
The present invention applies to highly available automation networks arranged in a ring topology connecting critical devices that require seamless communication in case of link or device failure. The network coupling device is connected over a respective first and second port in a communication network with a ring topology operating with full duplex links, and inserts, when sending, in the ring two duplicate frames, one over each of its ports, said frames containing information allowing to identify these two frames as being a a pair of duplicates of the same frame. Each similar device in the ring comprises a Switching Element able to receive a frame from one port and to forward it to the other port without modification, with the exception that the Switching Element discards a frame that was originally sent by that same node and/or discards a frame that it already forwarded in that direction, and/or discards a frame that it cannot recognize as being a member of a pair. A further similar device on the ring is able to receive the two duplicate frames and to pass the earlier of a pair to the application, while discarding the later, based on the identification within the frames. |
