SEL-787-2, -3, -4 Data Sheet
Schweitzer Engineering Laboratories, Inc.
24
Additional Features
M
IRRORED
B
ITS
Relay-to-Relay
Communications
The SEL-patented M
IRRORED
B
ITS
communications
technology provides bidirectional relay-to-relay digital
communication. M
IRRORED
B
ITS
communications can
operate independently on as many as two EIA-232 rear
serial ports and one fiber-optic rear serial port on a single
SEL-787.
This bidirectional digital communication creates eight
additional virtual outputs (transmitted M
IRRORED
B
ITS
)
and eight additional virtual inputs (received M
IRRORED
B
ITS
) for each serial port operating in the M
IRRORED
B
ITS
mode (see
). Use these M
IRRORED
B
ITS
to
transmit/receive information between upstream relays
and a downstream relay to enhance coordination and
achieve faster tripping for downstream faults. M
IRRORED
B
ITS
technology also helps reduce total scheme
operating time by eliminating the need to assert output
contacts to transmit information.
Figure 35
M
IRRORED
B
ITS
Transmit and Receive Bits
Status and Trip Target LEDs
The SEL-787 includes 24 tricolor status and trip target
LEDs on the front panel. When shipped from the factory,
all LEDs are predefined and fixed in settings. You can
reprogram these LEDs for specific applications. This
combination of targets is explained and shown in
. Some front-panel relabeling of LEDs may be
needed if you reprogram them for unique or specific
applications—see
Event Messenger Points
The SEL-787, when used with the SEL-3010, allows for
ASCII-to-voice translation of as many as 32 user-defined
messages, along with analog data that has been measured
or calculated by the relay. This combination allows you
to receive voice message alerts (on any phone) regarding
Relay Word bit transitions in the relay.
Verbal notification of breaker openings, fuse failures,
RTD alarms, etc., can be sent directly to your cell phone
through the use of your SEL-787 and an SEL-3010 (must
be connected to an analog telephone line). In addition,
messages can include an analog value such as current,
voltage, or power measurements made by the SEL-787.
Configurable Labels
Use the configurable labels to relabel the operator con-
trols and LEDs (shown in
) to suit your installa-
tion requirements. This feature includes preprinted labels
(with factory-default text), blank label media, and a
Microsoft Word template on CD-ROM. This allows
quick, professional-looking labels for the SEL-787.
Labels may also be customized without the use of a PC
by writing the new label on the blank stock provided.
The ability to customize the control and indication fea-
tures allows specific utility or industry procedures to be
implemented without the need for adhesive labels.
Web Server
The web server allows you to communicate with the
relay via the Ethernet port without the need for additional
communication software (web browser required). The
web server allows you to access metering and monitoring
data and to perform firmware upgrades.
Firmware Download Via Ethernet
Ports
Relay firmware can be securely downloaded to your
relay via the Ethernet port. The firmware is digitally
signed to prevent malicious modification. Additionally,
the Ethernet firmware download allows you to access
and update all your network relays simultaneously.
SEL-787
Transmit
Receive
Transmit
Receive
.
.
.
.
Relay 2
0
0
0
1
0
0
.
.
.
.
1
0
0
0
0
0
TMB1
TMB2
TMB8
RMB1
RMB2
RMB8
RMB8
TMB1
TMB2
TMB8
.
.
.
.
.
.
RMB1
RMB2
.
.
