GE C30 Instruction Manual page 249

CHAPTER 5: SETTINGS
The C30 supports the Simple Network Time Protocol specified in RFC-2030. With SNTP, the C30 can obtain clock time over
an Ethernet network. The C30 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 setting enables or disables the SNTP feature on the C30.
SNTP FUNCTION
To use SNTP in unicast mode, set
is "Enabled," the C30 attempts to obtain time values from the SNTP/NTP server. Since many time values are
FUNCTION
obtained and averaged, it generally takes three to four minutes until the C30 clock is closely synchronized with the SNTP/
NTP server. It takes up to two minutes for the C30 to signal an SNTP self-test error if the server is offline.
To use SNTP in broadcast mode, set the
then listens to SNTP messages sent to the "all ones" broadcast address for the subnet. The C30 waits up to 18 minutes
(>1024 seconds) without receiving an SNTP broadcast message before signaling an SNTP self-test error.
The is 123 for normal SNTP operation. The change takes effect when the C30 is restarted.
SNTP UDP PORT NUMBER
Do not set more than one protocol to the same TCP/UDP port number, as this results in unreliable operation of
those protocols.
5.3.6.4 Local time
SETTINGS  PRODUCT SETUP  REAL TIME CLOCK  LOCAL TIME
 LOCAL TIME

The C30 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.
C30 CONTROLLER SYSTEM – INSTRUCTION MANUAL
SNTP UDP PORT

NUMBER: 123
to the SNTP/NTP server IP address. Once this address is set and
SNTP SERVER IP ADDR
setting to "0.0.0.0" and
SNTP SERVER IP ADDR
LOCAL TIME OFFSET

FROM UTC: 0.0 hr
DAYLIGHT SAVINGS

TIME: Disabled
DST START MONTH:

January
DST START DAY:

Sunday
DST START DAY

INSTANCE: First
DST START HOUR:

2:00
DST STOP MONTH:

January
DST STOP DAY:

Sunday
DST STOP DAY

INSTANCE: First
DST STOP HOUR:

2:00
Range: 1 to 65535 in steps of 1
to "Enabled." The C30
SNTP FUNCTION
Range: –24.0 to 24.0 hr in steps of 0.5
Range: Disabled, Enabled
Range: January to December (all months)
Range: Sunday to Saturday (all days of the week)
Range: First, Second, Third, Fourth, Last
Range: 0:00 to 23:00 in steps of one hour
Range: January to December (all months)
Range: Sunday to Saturday (all days of the week)
Range: First, Second, Third, Fourth, Last
Range: 0:00 to 23:00 in steps of one hour
PRODUCT SETUP
SNTP
5
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