PT-7828 User’s Manual
Featured Functions
3-10
Offset
Setting
Description
Factory Default
User-specified hour
This specifies the number of hours that the time
should be offset forward during Daylight
Savings Time.
None
System Up Time
This indicates how long the PT-7828 remained up since the last cold start. The up time is indicated
in seconds.
Time Zone
Setting
Description
Factory Default
Time zone
This specifies the time zone, which is used to
determine the local time offset from GMT
(Greenwich Mean Time).
GMT (Greenwich
Mean Time)
NOTE
Changing the time zone will automatically correct the current time. Make sure to set the time
zone before setting the time.
Time Server IP/Name
Setting
Description
Factory Default
IP address or name of time
server
This is the IP or domain address (e.g.,
192.168.1.1, time.stdtime.gov.tw, or
time.nist.gov).
None
IP address or name of
secondary time server
The PT-7828 will try to locate the secondary
NTP server if the first NTP server fails to
connect.
Time Server Query Period
Setting
Description
Factory Default
Query period
This parameter determines how frequently the
time is updated from the NTP server.
600 seconds
IEEE 1588 PTP
The following information is taken from the NIST website at http://ieee1588.nist.gov/intro.htm:
Time measurement can be accomplished using the IEEE Standard for a Precision Clock
Synchronization Protocol for Networked Measurement and Control Systems (IEEE 1588-2008) to
synchronize real-time clocks incorporated within each component of the electrical power system
for power automation applications.
IEEE 1588, which was published in November 2002, expands the performance capabilities of
Ethernet networks to control systems that operate over a communication network. In recent years
an increasing number of electrical power systems have been using a more distributed architecture
with network technologies that have less stringent timing specifications. IEEE 1588 generates a
master-slave relationship between the clocks, and enforces the specific timing requirements in
such power systems. All devices ultimately get their time from a clock known as the grandmaster
clock. In its basic form, the protocol is intended to be administration free.
