7.3
Date Code 20081022
Instruction Manual
SEL-787 Relay
Communications
Communications Interfaces
Fiber-Optic Serial
Port
Use the optional fiber-optic port for safety and large (500 m to 8 km)
communications distances.
Ethernet Port
Use the Ethernet port for interfacing with an Ethernet network environment.
SEL-787 Ethernet port choices include single or dual copper or fiber-optic
configurations. With dual Ethernet ports the unit has an unmanaged Ethernet
switch. Redundant configurations support automatic failover switching from
primary to backup network if a failure in the primary network is detected. In
addition to failover mode, the unit can operate in a “fixed connection (to
netport) mode” or in a “switched mode” (as an unmanaged switch).
Dual Network Port Operation
The SEL-787 dual Ethernet port option has two network ports. Network port
failover mode enables the dual Ethernet port to operate as a single network
adapter with a primary and standby physical interface. You can connect the
two network ports to the same network or to different networks depending on
your specific Ethernet network architecture.
Failover Mode
In the failover mode operation, the relay determines the active port. To use
failover mode, proceed with the following steps.
Step 1. Set NETMODE to FAILOVER.
Step 2. Set FTIME to the desired network port failover time.
Step 3. Set NETPORT to the preferred network interface.
On startup the relay communicates via NETPORT (primary port) selected. If
the SEL-787 detects a link failure on the primary port, it activates the standby
port after the failover time, FTIME, elapses. If the link status on the primary
link returns to normal before the failover time expires, the failover timer resets
and uninterrupted operation continues on the primary network port.
After failover, while communicating via standby port, the SEL-787 checks the
primary link periodically and continues checking until it detects a normal link
status. The relay continues to communicate via the standby port even after the
primary port returns to normal. The port of choice for communications is
reevaluated on change of settings or failure of the standby port or on reboot.
The relay returns to operation on the primary link under those conditions if it
detects a normal link status. When the active and backup links both fail, the
relay alternates checking for the link status of the primary and standby ports.
Unmanaged Switch Mode
If you have a network configuration where you want to use the relay as an
unmanaged switch, set NETMODE to SWITCHED. In this mode, both links
are enabled. The relay will respond to the messages received on either port.
All the messages received on one network port that are not addressed to the
relay will be transmitted out of the other port without any modifications. In
this mode NETPORT setting is ignored.
Fixed Connection Mode
If you have a single network and want to use only one network port, or if you
have both ports connected but want to force usage of only one port for various
reasons, set NETMODE to FIXED and set NETPORT to the port you want to
use. Only the selected network port operates and the other port is disabled.
NOTE:
If you change settings for
the host port in the relay and the
standby network port is active, the
relay resets and returns to operation
on the primary port.
Summary of Contents for SEL-787
Page 1: ...20081022 SEL 787 Transformer Protection Relay Instruction Manual PM787 01 NB ...
Page 6: ...This page intentionally left blank ...
Page 12: ...This page intentionally left blank ...
Page 18: ...This page intentionally left blank ...
Page 78: ...This page intentionally left blank ...
Page 206: ...This page intentionally left blank ...
Page 280: ...This page intentionally left blank ...
Page 334: ...This page intentionally left blank ...
Page 376: ...This page intentionally left blank ...
Page 388: ...This page intentionally left blank ...
Page 474: ...This page intentionally left blank ...
Page 508: ...This page intentionally left blank ...