Sel SEL-421 - ASCII Command Reference

Date Code 20111215 Reference Manual SEL-421 Relay
Section 9
R.Reference Manual
ASCII Command Reference
This section covers Description of Commands on page R.9.2.
You can use a communications terminal or terminal emulation program to set
and operate the SEL-421 Relay. This section explains the commands that you
send to the SEL-421 using SEL ASCII (American National Standard Code for
Information Interchange) communications protocol. The relay responds to
commands such as settings, metering, and control operations.
This section lists ASCII commands alphabetically. Commands, command
options, and command variables that you enter are shown in bold. Lower case
italic letters and words in a command represent command variables that you
determine based on the application (for example, circuit breaker number n = 1
or 2, remote bit number nn = 01–32, and level).
Command options appear with brief explanations about the command
function. Refer to the references listed with the commands for more
information on the relay function corresponding to the command or examples
of the relay response to the command.
You can simplify the task of entering commands by shortening any ASCII
command to the first three characters; for example, ACCESS becomes ACC.
Always send a carriage return <CR> character, or a carriage return character
followed by a line feed character <CR><LF> to command the relay to process
the ASCII command. Usually, most terminals and terminal programs interpret
the <Enter> key as a <CR>. For example, to send the ACCESS command,
type ACC <Enter>. For more information on SEL ASCII protocol, including
handshaking, see Section 5: SEL Communications Protocols.
Tables in this section show the access level(s) where the command or
command option is active. Access levels in the SEL-421 are Access Level 0,
Access Level 1, Access Level B (breaker), Access Level P (protection),
Access Level A (automation), Access Level O (output), and Access Level 2.
For information on access levels see Changing the Default Passwords on
page U.4.6.