24
SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System
Instruction Manual
Date Code 20210405
Device Installation
Avoiding Radio Interference From Adjacent Networks
The Network ID encoded in each message allows only SEL-FR12 Fault Receiv-
ers configured with the same Network ID to recognize that message. However,
the broadcast radio frequency (channel) selection is controlled by the Unit ID set-
ting in each SEL-FT50. The Network ID selection does
not
affect the radio chan-
nel.
In the example system shown in
Figure 17
, the Unit ID selections 01 through 06
are duplicated on each network. This channel sharing poses no problem when the
networks are monitoring separate distribution feeders and faults are isolated to
one network at a time.
In cases where two networks are on the same feeder, and some SEL-FT50 Fault
Transmitters on each network may simultaneously detect a fault, the Unit ID
assignments for those SEL-FT50 Fault Transmitters should be unique. This
avoids situations in which SEL-FT50 Fault Transmitters with a shared Unit ID
broadcast fault messages at the same time (on the same channel) and interfere
with one another.
Serial Port Settings
Configure the desired serial port baud rate through use of the control switch posi-
tions.
For best performance, choose the highest speed that matches the available
M
IRRORED
B
ITS
speed on the connected device.
Set the transmit address (
TX_ADD
) of the SEL-FR12 to match the receive address
of the connected device. Set the receive address (
RX_ADD
) of the SEL-FR12 to
match the receive transmit of the connected device.
Figure 19
outlines the control
switch settings. Do not set the TX and RX addresses of each device to the same
number because the SEL-FR12 detects a loopback condition when it receives its
own transmit address in the M
IRRORED
B
ITS
message. When the SEL-FR12
detects loopback, the
LOOP
LED illuminates and the
ROK
LED extinguishes.
Figure 18
Network ID Switch Selection
