Spectracom NetClock 9489 - 3.3 Managing Input References

2. Navigate to MANAGEMENT > Time Management: Local Clocks > (+): Local Clock.
3. From the UTC Offset pull-down menu, select “UTC -05:00”.
4. Select the Use DST Rules checkbox.
5. Select the Set DST Rules by Region checkbox.
6. From the DST Region drop-down list, select “US-Canada.”
7. Review the changes made and click the Submit button.
The unit will display the status of the change.
3.2.4.3 DST and UTC, GMT
Neither UTC, nor GMT ever change to Daylight Savings Time (DST). However, some of the
countries that use GMT switch to a different time zone offset during their DST period. The
United Kingdom is not on GMT all year, but uses British Summer Time (BST), which is one hour
ahead of GMT, during the summer months.
Additional information about regional time zones and DST can be found on the following web
sites: http://www.worldtimeserver.com/,
http://webexhibits.org/daylightsaving/b.html.
3.3 Managing Input References
3.3.1 Input Reference Priorities
NetClock can be synchronized to different time and frequency sources that are referred to as
Input References, or just References.
References can be a GNSS receiver, or other sources such as NTP, PTP, IRIG, ASCII or
HAVEQUICK time codes delivered into your NetClock unit via dedicated (mostly optional)
inputs. It is also possible to enter a system time manually, which NetClock then can synchronize
to.
Should you be installing new option cards, you will need to either manually setup the new
card in the Reference Priority Table, or use the Restore Factory Defaults option in the Reference Pri
ority Actions panel, in order to update the table with the new reference information.
In order for NetClock to declare synchronization, it needs both a valid 1PPS, and Time ref
erence.
The concept of Reference Priority allows the ranking of multiple references for redundancy. This
allows NetClock to gracefully fall back upon a lower ranking 1PPS or Time reference without
transitioning into Holdover, in case a reference becomes unavailable or invalid. The priority
3.3 Managing Input References
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