Schweitzer Engineering Laboratories SEL-351-5, Instruction Manual

Page: 667 / 706

Date Code 20070117
Instruction Manual SEL-351-5, -6, -7 Relay
Appendix I
R.Instruction Manual
M
IRRORED
B
ITS
(in Firmware Versions 6 and 7)
Overview
M
IRRORED
B
ITS®
is a direct relay-to-relay communications protocol that
allows protective relays to exchange information quickly and securely, and
with minimal expense. The information exchanged can facilitate remote
control, remote sensing, or communications-assisted protection schemes such
as POTT, DCB, etc. The SEL-351 Relay supports two M
IRRORED
B
ITS
channels, differentiated by the channel specifiers A and B. Bits transmitted are
called TMB1
x through TMB8 x , where x is the channel specifier (e.g., A or B),
and are controlled by the corresponding SEL
OGIC®
control equations. Bits
received are called RMB1 x through RMB8 x and are usable as inputs to any
SEL
OGIC
control equations. Channel status bits are called ROK x , RBAD x ,
CBAD x , and LBOK x and are also usable as inputs to any SEL
OGIC
control
equations. Further channel status information is available via the COM
command.
IMPORTANT:
Do not connect an
unconfigured port to a M
IRRORED
B
ITS
device. Otherwise, the relay will
appear to be locked up. Configure the
port first, and then connect the
device.