U.4.68
SEL-421/SEL-421-1 Relay
User’s Guide
Date Code 20020501
Basic Relay Operations
Configuring High-Accuracy Timekeeping
END<Enter>
to end the settings session. Type
N<Enter>
(for
no) to return to the Access Level 2 prompt. (If you changed
either setting ETPPS or ETIRIG from N to Y, save the new
settings by answering
Y<Enter>
to the Save settings (Y,N) ?
prompt).
=>>SET G EGADVS TERSE<Enter>
Global
Global Enables
Advanced Global Setting (Y,N) EGADVS := N ?
Y<Enter>
Control Inputs (Global)
Input Pickup Level (15-265 Vdc) GINP := 85 ?
><Enter>
Settings Group Selection
Select Setting Group 1 (SELogic Equation)
SS1 := PB3 AND NOT SG1
?
><Enter>
Frequency Estimation
Alternate Freq. Source (SELogic Equation)
EAFSRC := NA
?
><Enter>
Time and Date Management
PPS/IRIG Time Source (Y,N) ETPPS := Y ?
<Enter>
IRIG Time Source (Y,N) ETIRIG := Y ?
<Enter>
Current and Voltage Source Selection
Current and Voltage Source Selection (Y,N,1,2) ESS := N ?
END<Enter>
Save settings (Y,N) ?
N<Enter>
Settings aborted
Figure 4.62
Confirming the High-Accuracy Timekeeping Enable Settings.
Step 5. Confirm that the relay is operating in the high-accuracy PPS
mode. Type
TIME Q<Enter>
. The relay displays information
. The Time Source will be PPS,
indicating that the relay internal clock is locked to the 1k PPS
input signal.
=
>
TIME Q<Enter>
Relay 1
Date: 03/15/2001 Time: 14:09:14.803
Station A
Serial Number: 2001001234
Time Source: PPS
Last Update Source: PPS
Sync Status: SYNC
FF
Time Mark Period:
0.000
m
s
PPS
Time Mark Period: 1000.018
m
s
IRIG Time Mark Period: 1000.000 ms
Internal Clock Period:
24.999816 ns
=
>
Figure 4.63
Results of the TIME Q Command.
TIME Q Descriptions
The TIME Q command provides details about relay timekeeping
. The header line internal clock setting is initially calibrated at the
SEL factory; you do not need to connect a PPS mode satellite receiver to get
good time results from the SEL-421 Relay. The Time Source provides the
present high-accuracy timing input source; entries for this line are PPS, IRIG,
and OTHER. The Last Update Source reports the source from which the relay
referenced the last time value measurement. Entries for this line can be high-
accuracy or low-accuracy sources.
lists the possible Last Update
Source values for the SEL-421 Relay.
Summary of Contents for SEL-421
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