GE C30 Instruction Manual page 199

CHAPTER 5: SETTINGS
In unusual cases where the length of the link is different in different directions, set this setting to the number of
nanoseconds the Ethernet propagation delay to the relay is longer than the mean of path propagation delays to and from
the relay. For instance, if it is known say from the physical length of the fibers and the propagation speed in the fibers that
the delay from the relay to the Ethernet switch it is connected to is 9000 ns and that the delay from the switch to the relay
is 11000 ns, then the mean delay is 10000 ns, and the path delay asymmetry is 11000 - 10000 = +1000 ns.
5.3.6.3 SNTP protocol
SETTINGS  PRODUCT SETUP  REAL TIME CLOCK  SNTP PROTOCOL
 SNTP PROTOCOL

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. Unicast SNTP is supported. The UR series relays do not support the broadcast, multicast, or
anycast SNTP functionality.
The setting enables or disables the SNTP feature on the C30.
SNTP FUNCTION
To use SNTP, set
SNTP SERVER IP ADDR
"Enabled," the C30 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 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.
The is 123 for normal SNTP operation. If SNTP is not required, close the port by setting the port
SNTP UDP PORT NUMBER
number to 0, after which the change takes effect when the C30 is restarted.
Do not set more than one protocol to the same TCP/UDP port number, as this results in unreliable operation of
those protocols.
NOTE
5.3.6.4 Local time
SETTINGS  PRODUCT SETUP  REAL TIME CLOCK  LOCAL TIME
 LOCAL TIME

C30 CONTROLLER SYSTEM – INSTRUCTION MANUAL
SNTP FUNCTION:

Disabled
SNTP SERVER IP ADDR:

0.0.0.0
SNTP UDP PORT

NUMBER: 123
to the SNTP/NTP server IP address. Once this address is set and
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
Range: Enabled, Disabled
Range: standard IP address format
Range: 0 to 65535 in steps of 1
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
Range: January to December (all months)
Range: Sunday to Saturday (all days of the week)
PRODUCT SETUP
is
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