Figure 85: Hsr Network; Figure 86: Hsr Network With Redboxes - ABB UniGear Series Engineering Manual

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High Availability Seamless Redundancy (HSR) network
The HSR ring applies the PRP principle of parallel operation to a single ring. For each message
sent, a node sends two frames, one over each port. Both frames circulate in opposite direc-
tions over the ring and every node forwards the frames it receives from one port to the other.
When the originating node receives a frame it sent, it discards the frame to avoid loops.
HSR redundancy is supported by Relion
640 series.

Figure 85: HSR network

HSR network with redboxes

Figure 86: HSR network with redboxes

The maximum number of IEDs in a HSR ring is 30. It is not recommended to configure more
than four SMV senders due to all information is sent into both directions in parallel.
1V LG 5 000 07 E
® 615 (RED615 only via fiber optic interfaces), 620 and
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