3-18
Communications
Date Code 970103
SEL-251, -2, -3 Instruction Manual
prevents confusion among station operators and readers, it can be inconvenient if the relay tester
requires targets to remain on another level. Targets remain in the specified level if you assign the
AUTO setting to a port with zero timeout or set both TIME1 and TIME2 to zero. This halts
automatic message transmission to a port which may be timed out.
TARGET R
You can reset front panel targets to TAR 0 and clear them remotely or locally with the TARGET
R command. Type TARGET R <ENTER> to reset and clear the targets as shown in the
following example.
=>TARGET R <ENTER>
TARGET R <ENTER>
Targets reset
INST A B C Q N RS LO
0 0 0 0 0 0 1 0
=>
TIME hh:mm:ss
TIME displays the internal clock. To set the clock, type
TIME
and the desired setting, then
press
<ENTER>
. Separate the hours, minutes, and seconds with colons, semicolons, spaces,
commas, or slashes. To set the clock to 23:30:00, enter:
=>TIME 23:30:00 <ENTER>
TIME 23:30:00 <ENTER>
23:30:00
=>
A quartz crystal oscillator provides the time base for the internal clock. You can set the clock
automatically through the relay time code input with a source of demodulated IRIG-B time code.
TRIGGER
TRIGGER generates an event record. After command entry, the relay responds "Triggered" and
displays a record summary.
=>TRIGGER <ENTER>
TRIGGER <ENTER>
Triggered
=>
Example 21.6 kV distribution feeder Date: 04/01/93 Time: 10:45:20.000
Event : TRIG Location: Shot: 0 Targets:
Currents (A pri), ABCQN: 347 354 355 5 6
=>
Use TRIGGER to inspect input voltages. For example, when the relay is first installed, execute
the TRIGGER command, draw the phasors (
Section 4: Event Reporting
explains how to do
this), and check for the proper polarity and phase sequence of the inputs.