Patent ID: 9106595
Filing Date: 2015-08-11
Classification: H04L

Abstract:
1. A method of transmitting frames in a communication network interconnecting a plurality of synchronized nodes of a Process Control (PC) or Substation Automation (SA) system, wherein the nodes periodically transmit regular frames comprising time-critical data, and wherein the nodes non-periodically transmit sporadic frames, the method comprising: transmitting, by each node of the plurality of nodes of the Process Control (PC) or Substation Automation (SA) system, at the beginning of a common transmission period, a regular frame; receiving, by at least one node of the Process Control (PC) or Substation Automation (SA) system, regular frames from a first neighboring node, and forwarding within the common transmission period, the received regular frames to a second neighboring node, and delaying, by the at least one node of the Process Control (PC) or Substation Automation (SA) system, transmission of a sporadic frame until forwarding of all received regular frames is completed, wherein the communication network is a ring, comprising: transmitting, by a node of origin, a frame and a duplicate frame to a first and second neighboring node, respectively, with the frame and the duplicate frame being identified by means of a redundancy identifier, and wherein the redundancy identifier comprises the length of the frame, comprising: verifying, by the node of origin and prior to transmission of a sporadic frame or a duplicate sporadic frame, whether the transmission of the sporadic frame or of the duplicate sporadic frame can be completed before the start of the next transmission period, based on the redundancy identifier comprising the length of the frame.