27
Date Code 20210405
Instruction Manual
SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System
Device Installation
For critical links, the best practice is to have at least 15 dB of fade margin above
your receive sensitivity (which corresponds to at least eight illuminated LEDs)
for a reliable link. At lower RSSI values, the device is more susceptible to
unwanted interference from other radio systems.
When the SEL-FR12 is receiving link messages, the RSSI indicated by the
LINK
LEDs updates every 15 seconds. If the SEL-FR12 misses a link message, the
LINK
LEDs that represent the RSSI will flash at the last measured value of a successful
message. This will persist until another successful message is received or the
SEL-FR12 is turned off.
Press and hold the
TARGET RESET
pushbutton for two more seconds to enter Read
Settings mode (see
Read Settings on page 30
for details), and then for two sec-
onds longer to get back to Normal mode. The SEL-FR12 will default to Normal
mode automatically after 30 minutes.
Connecting the SEL-FR12 to Other SEL Devices
The SEL-FR12 uses the MB8 M
IRRORED
B
ITS
protocol. The following examples
give sample configurations for SEL devices that operate with the SEL-FR12. For
each of these examples, select BAUD = 38400, RX_ADD = 2, and TX_ADD = 1
on the SEL-FR12. Only the minimum settings required are shown. Consult the
appropriate instruction manual to ensure proper settings for your particular
M
IRRORED
B
ITS
application.
SEL-351, SEL-751 Relays, SEL-351R, and SEL-651R Recloser Controls
PROTO = MB8A*
SPEED = 38400
TXID = 2
RXID = 1
* = MB8A or MB8B may be used
Table 6
RSSI Specifications for FR12-0004/FR12-0005 (Europe, Australia,
and New Zealand)
Number of LINK LEDs Illuminated
RSSI (High Gain Mode)
a
a
For RSSI values in Low Gain mode, add 16 dB to each value.
0
–105 dBm or worse
1
–103 dBm
2
–101 dBm
3
–99 dBm
4
–97 dBm
5
–95 dBm
6
–93 dBm
7
–91 dBm
8
–89 dBm
9
–87 dBm
10
–85 dBm
11
–83 dBm
12
–81 dBm or better
