Sel SEL-787 - Page 299

7.11
Date Code 20150130 Instruction Manual SEL-787 Relay
Communications
Communications Protocols
MIRRORED BITS Protocol
The SEL-787 supports two MIRRORED BITS communications channels,
designated A and B. Within each M
IRRORED BITS communications message
for a given channel (A or B), there are eight logical data channels (1–8). You
can, for example, set MBA on Port 3 of the base unit and MBB on Port 4A of
the optional communications card. Attempting to set the PROTO setting to
MBA, MB8A, or MBTA when channel A is already assigned to another port
(or MBB, MB8B, or MBTB when channel B is already assigned on another
port) results in the following error message:
This Mirrored Bits channel
is assigned to another port.
After displaying the error message, the
device returns to the PROTO setting for reentry.
C37.118 Protocol
The SEL-787 provides C37.118 protocol (synchrophasor data) support at one
of the serial ports F, 2, 3, or 4. The protocol is described in Appendix H:
Synchrophasors.
Modbus RTU Protocol
The SEL-787 provides Modbus RTU support. Modbus is a protocol described
in Appendix E: Modbus RTU Communications.
DNP3 (Distributed Network Protocol)
The SEL-787 provides DNP3 protocol support if the option is selected. The
DNP3 protocol is described in Appendix D: DNP3 Communications.
DeviceNet
The SEL-787 provides DeviceNet support. DeviceNet is an optional protocol
described in Appendix G: DeviceNet Communications.
Ethernet Protocols
As with other communications interfaces, you must choose a data exchange
protocol that operates over the Ethernet network link in order to exchange
data. The relay supports FTP, Telnet, Ping, Modbus/TCP, IEC 61850, and
DNP3 LAN/WAN protocols.
You should carefully design your Ethernet network to maximize reliability,
minimize system administration effort, and provide adequate security. Work
with a networking professional to design your substation Ethernet network.
FTP Server
Use the single FTP (File Transfer Protocol) session to access the following
files:
➤ CFG.XML—Configuration read-only file in XML format
➤ CFG.TXT—Configuration read-only file in TXT format
➤ ERR.TXT—Error read-only file in TXT format
➤ SET_61850.CID—IEC 61850 CID read-write file
➤ SET_xx.TXT—Setting files in TXT format
FTP is a standard TCP/IP protocol for exchanging files. A free FTP application is
included with most web browser software. You can also obtain a free or inexpensive
FTP application from the Internet. When you connect to the relay Ethernet port,
you will find files stored in the root (top-level) directory.