CHAPTER 5: SETTINGS
PRODUCT SETUP
N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
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The N60 supports the Simple Network Time Protocol specified in RFC-2030. With SNTP, the N60 can obtain clock time over
an Ethernet network. The N60 acts as an SNTP client to receive time values from an SNTP/NTP server, usually a dedicated
product using a GPS receiver. UR family relays support unicast, broadcast, multicast, and anycast SNTP functionality.
The
SNTP FUNCTION
setting enables or disables the SNTP feature on the N60.
To use SNTP in unicast mode, set
SNTP SERVER IP ADDR
to the SNTP/NTP server IP address. Once this address is set and
SNTP
FUNCTION
is “Enabled,” the N60 attempts to obtain time values from the SNTP/NTP server. Since many time values are
obtained and averaged, it generally takes three to four minutes until the N60 clock is closely synchronized with the SNTP/
NTP server. It takes up to two minutes for the N60 to signal an SNTP self-test error if the server is offline.
To use SNTP in broadcast mode, set the
SNTP SERVER IP ADDR
setting to “0.0.0.0” and
SNTP FUNCTION
to “Enabled.” The N60
then listens to SNTP messages sent to the “all ones” broadcast address for the subnet. The N60 waits up to 18 minutes
(>1024 seconds) without receiving an SNTP broadcast message before signaling an SNTP self-test error.
The
SNTP UDP PORT NUMBER
is 123 for normal SNTP operation. The change takes effect when the N60 is restarted.
5.3.7.4 Local time
SETTINGS
PRODUCT SETUP
REAL TIME CLOCK
LOCAL TIME
The N60 maintains two times: local time and Universal Coordinated Time (UTC). Local time can be provided by IRIG-B
signals. UTC time is provided by SNTP servers.
The real-time clock (RTC) and time stamps reported in historical records and communication protocols can be incorrect if
the Local Time settings are not configured properly.
See the IRIG-B section in the Installation chapter for guidance on these settings when using an IRIG-B source that sets the
IRIG-B control bits according to IEEE Std 1344-1995.
LOCAL TIME OFFSET FROM UTC
— Used to specify the local time zone offset from UTC (Greenwich Mean Time) in hours. Time
zones in the eastern hemisphere have positive values; time zones in the western hemisphere have negative values. A value
of zero causes the relay to use UTC for local time. This setting has two uses. When the system RTC is synchronized with a
communications protocol providing only local time or it is free-running, the offset setting is used to calculate UTC from the
Do not set more than one protocol to the same TCP/UDP port number, as this results in unreliable operation of
those protocols.
LOCAL TIME
LOCAL TIME OFFSET
FROM UTC: 0.0 hr
Range: –24.0 to 24.0 hr in steps of 0.5
DAYLIGHT SAVINGS
TIME: Disabled
Range: Disabled, Enabled
DST START MONTH:
January
Range: January to December (all months)
DST START DAY:
Sunday
Range: Sunday to Saturday (all days of the week)
DST START DAY
INSTANCE: First
Range: First, Second, Third, Fourth, Last
DST START HOUR:
2:00
Range: 0:00 to 23:00 in steps of one hour
DST STOP MONTH:
January
Range: January to December (all months)
DST STOP DAY:
Sunday
Range: Sunday to Saturday (all days of the week)
DST STOP DAY
INSTANCE: First
Range: First, Second, Third, Fourth, Last
DST STOP HOUR:
2:00
Range: 0:00 to 23:00 in steps of one hour