Selecting a Standard Redundancy Method for Highly Available Industrial Networks
Hubert Kirrmann, Dacfey Dzung · 2006
Availability of Industrial Ethernet networks can be increased by providing redundant links and nodes. Although many specifications of Industrial Ethernet have been submitted to the International Electrotechnical Committee (IEC), they do not disclose methods to implement network redundancy. A working group of the IEC will, as part of the fieldbus maintenance team, issue guidelines for implementing redundancy in switched networks. Since the redundancy is dictated by the plant and less by the network, several solutions are studied. While less time critical processes can be satisfied by a standby solution with alternate links, hard real time systems require a full duplication and parallel operation of redundancy. Both methods can be combined to increase further availability. Network safety or security is not considered here.