GE N60 Instruction Manual page 199

CHAPTER 5: SETTINGS
— While this port setting is selected to disabled, PTP is disabled on this port. The relay does not
PORT 1 ... 3 FUNCTION
generate or listen to PTP messages on this port.
PORT 1 ... 3 PATH DELAY ADDER
being used to synchronize the relay's real time clock. This is to compensate to the extent practical for time delivery delays
not compensated for in the network. In a fully compliant PP network, the peer delay and the processing delay mechanisms
compensate for all the delays between the grandmaster and the relay. In such networks, make this setting zero.
In networks containing one or more switches and/or clocks that do not implement both of these mechanisms, not all
delays are compensated, so the time of message arrival at the relay is later than the time indicated in the message. This
setting can be used to approximately compensate for this delay. However, as the relay is not aware of network switching
that dynamically changes the amount of uncompensated delay, there is no setting that always and completely corrects
for uncompensated delay. A setting can be chosen that reduces the worst-case error to half of the range between
minimum and maximum uncompensated delay, if these values are known.
PORT 1 ... 3 PATH DELAY ASSYMMETRY
mechanism to compensate for any difference in the propagation delay between the two directions of a link. Except in
unusual cases, the two fibers are of essentially identical length and composition, so make this setting zero.
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 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. 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 N60.
SNTP FUNCTION
To use SNTP, set
SNTP SERVER IP ADDR
"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.
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 N60 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

N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
— The time delivered by PTP is advanced by the time value in this setting prior to the time
— This setting corresponds to "delayAsymmetry" in PTP, which is used by the peer delay
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
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
PRODUCT SETUP
5
is
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