350 Daisy Chain - GE 350 Communications Manual

CHAPTER 3: ETHERNET INTERFACE

350 Daisy Chain

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SR3 SERIES PROTECTIVE RELAY PLATFORM – COMMUNICATIONS GUIDE
A daisy chain is an interconnection of devices where each device is connected in series to
the next.
When an Ethernet daisy-chain redundancy is selected, the 350 relay has two Ethernet
ports and it is working as an unmanaged Ethernet switch. The two Ethernet ports are used
for connecting each device to the ports of its two neighboring devices, see figure.
Figure 3-4: Ethernet daisy-chain redundancy
Each device in the daisy chain forwards the message until it reaches the destination.
Ports A and B use the same MAC (physical device) address and operate by chaining one
device with the next one.
It is important not to create a loop in this topology. Both ends of the chain can be
connected to different networks. The device operates only with one IP address through
these two ports.
If a closed loop configuration is required, it is possible to use two RSTP switches as shown:
Figure 3-5: Ethernet daisy-chain loop with two RSTP switches
350 REDUNDANCY OPTIONS
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