User's Manual

SEL-3031 Instruction Manual Date Code 20091009
Settings and Commands
Settings
4.14
The protocol setting defines the type of data that will be passing through the serial port.
This setting automatically sets parameters in the radio to optimize best performance.
Any of the three serial ports may be set to any of the protocols. Ports 2 and 3 are always
EIA-232 ports. For example, you have three ports of M
IRRORED BITS
®
(MB8), or any
combination or MB8, MODBUS, and STANDARD.
PROTO sets the intended protocol used to communicate through the radio ports. Set to
STANDARD for all byte-oriented protocols such as DNP3, ASCII, Synchrophasors, or
file transfer. This is the default setting for PROTO and should be used unless you are
using M
IRRORED BITS or MODBUS. Set PROTO to MB8 to work with SEL
M
IRRORED BITS devices. The SEL-3031 only supports MB8 MIRRORED BITS protocol.
See Section 3: Job Done Examples for more information on setting up MIRRORED
B
ITS. Set PROTO to MODBUS when used with Modbus protocol. When PROTO is set
to either STANDARD or MODBUS the radio will not perform the 32-bit CRC check
on the received data. If you do not have a good link with high availability you will see
noise on the channel. These errors are better handled by the communications protocols
to ignore this data rather than have conflicting retry messages between the radio and
communications protocols. If PROTO is set to MB8, the 32-bit CRC will remove any
data that does not pass the CRC. The data rate on all three ports is fixed at 19200 bps. If
the unit has an SEL-3044 Encryption Card then the data rate is fixed at 9600 bps.
NOTE: If you are using the SEL-3044 Encryption Card and
PROTO is equal to MB8 you must change the connected
devices’ RMBxPU and RMBxDO settings = 2 to maintain
the same level of channel security as standard MB8
protocol. This will delay operation by one processing
interval but will give you a higher level of channel
security.
Ta b le 4. 6 Por t X
a
Settings
a. X = 1, 2, or 3.
Settings Prompt Settings Range Setting Name := Factory Default
Protocol STANDARD, MB8, MODBUS PROTO := STANDARD
CTS State Asserted, Deasserted CTS := DEASSERTED
Echo ON, OFF ECHO := OFF