User's Manual

Date Code 20091009 SEL-3031 Instruction Manual
Settings and Commands
Commands
4.15
The CTS setting is used to set the state of the CTS (Pin 7) line on each of the ports. In
most cases this setting should be set to deasserted. Most SEL devices require CTS
deasserted in order for them to respond to DNP requests. The SEL-3031 does not
support hardware flow control. It will only assert or deassert the CTS line to signal
connected equipment to continue communication.
The ECHO setting is only enabled when Port 1 is ordered as an EIA-485 device. This
setting is used to set up a two-wire versus four-wire EIA-485 connection. The default
ECHO setting is set to ON which works with four-wire EIA-485 applications. For two-
wire operation, the ECHO setting must be set to OFF, and Pins 1 and 7 and Pins 2 and
8 must be connected together (see Table 2 .9 ).
Commands
Access Levels
Issue commands to an SEL-3031 serial port to view or change device settings or
retrieve information. For security, these commands are available on different password-
protected access levels. Throughout this section each command description indicates
the access level at which the command is available. There are three access levels in the
device, offering varying levels of control.
➤ Access Level 0 commands are the lowest security level. Access
Level 0 commands support minimum identification.
➤ Access Level 1 commands are for reviewing information only (e.g.,
status) and not for making any changes.
➤ Access Level 2 commands are for changing device settings.
Go to Communications on page 4.2 for instructions on connecting to the SEL-3031
through the USB interface.
The virtual serial interface created from the USB port must be set to 9600 bps, 8 data
bits, 1 stop bit, and no parity to communicate to the SEL-3031.
Table 4.7 Fixed Port Settings
Port Setting Fixed Port Settings
Fixed Port Settings With
SEL-3044 Card
Data Rate 19200 bps 9600 bps
Data Bits 8 8
Parity None None
Stop Bit 1 1
RTS/CTS Flow Control Off Off