GE L30 Instruction Manual page 326

PRODUCT SETUP
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.
5.3.7.3 SNTP protocol
SETTINGS  PRODUCT SETUP  REAL TIME CLOCK  SNTP PROTOCOL
 SNTP PROTOCOL

The L30 supports the Simple Network Time Protocol specified in RFC-2030. With SNTP, the L30 can obtain clock time over
an Ethernet network. The L30 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
To use SNTP in unicast mode, set
is "Enabled," the L30 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 L30 clock is closely synchronized with the SNTP/
NTP server. It takes up to two minutes for the L30 to signal an SNTP self-test error if the server is offline.
5
To use SNTP in broadcast mode, set the
then listens to SNTP messages sent to the "all ones" broadcast address for the subnet. The L30 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
Do not set more than one protocol to the same TCP/UDP port number, as this results in unreliable operation of
those protocols.
5.3.7.4 Local time
SETTINGS  PRODUCT SETUP  REAL TIME CLOCK  LOCAL TIME
 LOCAL TIME

5-112
SNTP FUNCTION:

Disabled
SNTP SERVER IP ADDR:

0.0.0.0
SNTP UDP PORT

NUMBER: 123
setting enables or disables the SNTP feature on the L30.
SNTP SERVER IP ADDR
SNTP SERVER IP ADDR
is 123 for normal SNTP operation. The change takes effect when the L30 is restarted.
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: 1 to 65535 in steps of 1
to the SNTP/NTP server IP address. Once this address is set and
setting to "0.0.0.0" and
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)
L30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
to "Enabled." The L30
SNTP FUNCTION
SNTP