where the highest performance class with a total transmission time of 3 ms is
supported. The protection relay meets the GOOSE performance requirements for
tripping applications in distribution substations, as defined by the IEC 61850
standard.
The protection relay can support five simultaneous clients. If PCM600 reserves one
client connection, only four client connections are left, for example, for IEC 61850
and Modbus.
All communication connectors, except for the front port connector, are placed on
integrated optional communication modules. The protection relay can be connected to
Ethernet-based communication systems via the RJ-45 connector (100Base-TX) or the
fiber-optic LC connector (100Base-FX). An optional serial interface is available for
RS-485 communication.
2.7.1
Self-healing Ethernet ring
For the correct operation of self-healing loop topology, it is essential that the external
switches in the network support the RSTP protocol and that it is enabled in the
switches. Otherwise, connecting the loop topology can cause problems to the
network. The protection relay itself does not support link-down detection or RSTP.
The ring recovery process is based on the aging of the MAC addresses, and the link-
up/link-down events can cause temporary breaks in communication. For a better
performance of the self-healing loop, it is recommended that the external switch
furthest from the protection relay loop is assigned as the root switch (bridge priority
= 0) and the bridge priority increases towards the protection relay loop. The end links
of the protection relay loop can be attached to the same external switch or to two
adjacent external switches. A self-healing Ethernet ring requires a communication
module with at least two Ethernet interfaces for all protection relays.
Section 2
1MRS757455 E
REB611 overview
20
REB611
Application Manual
