GE N60 Instruction Manual

Also see for N60: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

Contents

CHAPTER 5: SETTINGS PRODUCT SETUPN60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL 5-835PORT 1 ... 3 FUNCTION — While this port setting is selected to disabled, PTP is disabled on this port. The relay does notgenerate or listen to PTP messages on this port.PORT 1 ... 3 PATH DELAY ADDER — The time delivered by PTP is advanced by the time value in this setting prior to the timebeing used to synchronize the relay’s real time clock. This is to compensate to the extent practical for time delivery delaysnot compensated for in the network. In a fully compliant PP network, the peer delay and the processing delay mechanismscompensate 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 alldelays are compensated, so the time of message arrival at the relay is later than the time indicated in the message. Thissetting can be used to approximately compensate for this delay. However, as the relay is not aware of network switchingthat dynamically changes the amount of uncompensated delay, there is no setting that always and completely correctsfor uncompensated delay. A setting can be chosen that reduces the worst-case error to half of the range betweenminimum and maximum uncompensated delay, if these values are known.PORT 1 ... 3 PATH DELAY ASSYMMETRY — This setting corresponds to “delayAsymmetry” in PTP, which is used by the peer delaymechanism to compensate for any difference in the propagation delay between the two directions of a link. Except inunusual 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 ofnanoseconds the Ethernet propagation delay to the relay is longer than the mean of path propagation delays to and fromthe relay. For instance, if it is known say from the physical length of the fibers and the propagation speed in the fibers thatthe delay from the relay to the Ethernet switch it is connected to is 9000 ns and that the delay from the switch to the relayis 11000 ns, then the mean delay is 10000 ns, and the path delay asymmetry is 11000 - 10000 = +1000 ns.5.3.6.3 SNTP protocolSETTINGS  PRODUCT SETUP  REAL TIME CLOCK  SNTP PROTOCOLThe N60 supports the Simple Network Time Protocol specified in RFC-2030. With SNTP, the N60 can obtain clock time overan Ethernet network. The N60 acts as an SNTP client to receive time values from an SNTP/NTP server, usually a dedicatedproduct using a GPS receiver. Unicast SNTP is supported. The UR series relays do not support the broadcast, multicast, oranycast SNTP functionality.The SNTP FUNCTION setting enables or disables the SNTP feature on the N60.To use SNTP, 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 andaveraged, it generally takes three to four minutes until the N60 clock is closely synchronized with the SNTP/NTP server. Ittakes up to two minutes for the N60 to signal an SNTP self-test error if the server is offline.The SNTP UDP PORT NUMBER is 123 for normal SNTP operation. If SNTP is not required, close the port by setting the portnumber to 0, after which the change takes effect when the N60 is restarted.5.3.6.4 Local timeSETTINGS  PRODUCT SETUP  REAL TIME CLOCK  LOCAL TIME SNTP PROTOCOL  SNTP FUNCTION:DisabledRange: Enabled, Disabled SNTP SERVER IP ADDR:0.0.0.0Range: standard IP address format SNTP UDP PORTNUMBER: 123Range: 0 to 65535 in steps of 1NOTEDo not set more than one protocol to the same TCP/UDP port number, as this results in unreliable operation ofthose protocols. LOCAL TIME  LOCAL TIME OFFSETFROM UTC: 0.0 hrRange: –24.0 to 24.0 hr in steps of 0.5