User's Manual

Date Code 20091009 SEL-3031 Instruction Manual
Job Done Examples
High-Speed Teleprotection or Control With M
IRRORED BITS Communications
3.3
SEL-351, SEL-311, and SEL-700 Series MIRRORED BITS Settings
The required settings for the SEL-351 are shown below. These settings are similar to
all of the SEL-351, SEL-311, and SEL-700 series of relays. To establish a
communication link via the radio, the most critical settings are PROTO, SPEED,
RTSCTS, RXID, and TXID.
=>SHO P 2 <Enter>
Port 2
PROTO = MB8A
SPEED = 19200 RTSCTS= N RBADPU= 60 CBADPU= 1000
RXID = 1 TXID = 2 RXDFLT=XXXXXXXX
RMB1PU= 1 RMB1DO= 1 RMB2PU- 1 RMB2DO= 1
RMB3PU= 1 RMB3DO= 1 RMB4PU- 1 RMB4DO= 1
RMB5PU= 1 RMB5DO= 1 RMB6PU- 1 RMB6DO= 1
RMB7PU= 1 RMB7DO= 1 RMB8PU- 1 RMB8DO= 1
Figure 3.3 SEL-351 Port Settings for MIRRORED BITS Connection
The SEL-3031 locks all three serial ports to 19200 bps (8, N, 1). You cannot change the
port speed. If the SEL-3044 Encryption Card is used then the data rate changes to 9600
bps (8, N, 1).
NOTE: If you are using the SEL-3044 Encryption Card, you
must change the connected devices’ RMBxPU and
RMBxDO settings = 2 to maintain the same level of
channel security as the standard MB8 protocol. This will
delay operation by one processing interval but will give
you a higher level of channel security.
Set PROTO equal to MB8x, where x equals A or B depending on which MIRRORED
B
ITS channel is used.
NOTE: This setting is slightly different in the SEL-2100 Logic
Processor, SEL-3530 Real-Time Automation Controller
(RTAC), and SEL-321 Relay.
Set SPEED equal to 19200 (or 9600 if the encryption card is installed).
Set RTSCTS (hardware handshaking) to N to disable that option.
Set the RXID equal to one and TXID equal to two at the master end. At the remote end,
set the RXID equal to two and the TXID equal to one. The relays use these addresses to
prevent a relay from receiving messages from a secondary M
IRRORED BITS device if
the paths are accidentally connected wrong. The relay only receives messages sent by a
relay with the matching transmit address and vice versa.
To connect the relay to the radio, use an SEL-C285 cable (DB-9 male-to-DB-9 male
straight-through). If complete electrical isolation is desired between the radio and a
relay’s EIA-232 communications port, use the SEL-2812MR Fiber-Optic Transceiver
and fiber-optic cable to connect the relay to the radio.