Sel 411L - Figure 13.3 Results of the TIME Q Command

P.13.4
SEL-411L Relay Protection Manual Date Code 20151029
Time-Synchronized Measurements
Configuring High-Accuracy Timekeeping
If TSOK is not asserted, but TIRIG is asserted, the relay is in
regular IRIG timekeeping mode. Following is a list of possible
reasons for not entering HIRIG mode:
➢ The IRIG-B clock does not use the IEEE C37.118
control bit assignments, or the IRIG-B signal is not of
sufficient accuracy.
➢ The termination resistor, required by some IRIG clocks,
is not installed.
➢ If the time-source clock is reporting that its time error is
greater than 1 µs.
➢ The IRIG-B clock source is connected via Serial Port 1
instead of the IRIG-B BNC connector.
If neither TSOK nor TIRIG is asserted, the relay is not in an
IRIG time-source mode. Following is a list of possible reasons
for not entering IRIG mode:
➢ The IRIG-B clock signal is not of sufficient accuracy or
is improperly configured.
➢ The termination resistor, required by some IRIG clocks,
is not installed.
➢ The time source clock is not connected to an antenna.
Step 5. Type TIME Q <Enter> to confirm that the relay is operating
in the high-accuracy IRIG (HIRIG) mode.
The relay displays information similar to Figure 13.3.
The Time Source will be HIRIG, indicating that the relay
internal clock is locked to the high-accuracy IRIG input signal.
=>TIME Q <Enter>
Relay 1 Date: 10/06/2004 Time: 15:44:30.840
Station A Serial Number: 0000000000
Time Source: HIRIG
Last Update Source: HIRIG
IRIG Time Mark Period: 1000.000000 ms
Internal Clock Period: 24.999995 ns
=>
Figure 13.3 Results of the TIME Q Command
TIME Q Descriptions
The TIME Q command provides details about relay timekeeping (see
Figure 13.3). The internal clock of the relay is initially calibrated at the SEL
factory. An external IRIG source is required to eliminate clock drift. For high-
accuracy timekeeping functions such as synchrophasor measurement, the
connected clock must support IEEE C37.118—Annex F, IRIG-B control bit
assignments. The Time Source field provides the present high-accuracy timing
input source; entries for this line are HIRIG 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-priority or low-priority sources.
Table 13.2 lists the possible Last Update Source values for the relay.
NOTE: When EPMU := Y, the relay
year is updated automatically from
the connected clock IEEE C37.118—
Annex F, IRIG-B Control Bit
information.