ABB RELION REC615 Operation Manual page 44

Section 3
REC615 and RER615 overview
36
COM600
Ethernet switch
GUID-334D26B1-C3BD-47B6-BD9D-2301190A5E9D V3 EN
Figure 8: PRP solution
In case a laptop or a PC workstation is connected as a non-PRP node to one of the PRP
networks, LAN A or LAN B, it is recommended to use a redundancy box device or an
Ethernet switch with similar functionality between the PRP network and SAN to
remove additional PRP information from the Ethernet frames. In some cases, default
PC workstation adapters are not able to handle the maximum-length Ethernet frames
with the PRP trailer.
There are different alternative ways to connect a laptop or a workstation as SAN to a
PRP network.
• Via an external redundancy box (RedBox) or a switch capable of connecting to
PRP and normal networks
• By connecting the node directly to LAN A or LAN B as SAN
• By connecting the node to the protection relay's interlink port
HSR
HSR applies the PRP principle of parallel operation to a single ring, treating the two
directions as two virtual LANs. For each frame sent, a node, DAN, sends two frames,
one over each port. Both frames circulate in opposite directions over the ring and each
node forwards the frames it receives, from one port to the other. When the originating
node receives a frame sent to itself, it discards that to avoid loops; therefore, no ring
protocol is needed. Individually attached nodes, SANs, such as laptops and printers,
must be attached through a "redundancy box" that acts as a ring element. For example,
a 615 or 620 series protection relay with HSR support can be used as a redundancy
box.
Ethernet switch
IEC 61850 PRP
1MRS758754 B
SCADA
REC615 and RER615
Operation Manual