EndRun Sonoma D12, User Manual

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S o n o m a U s e r M a n u a l 139
"Smarter Timing Solutions"
Appendix
F
Leap Seconds
UTC stands for Universal Coordinated Time. UTC is the international time standard most commonly
used in the world and is the one used by the Network Time Protocol (NTP). A leap second insertion
is scheduled about every three years in order to keep UTC in alignment with the earth’s rotation.
Possible leap second insertions can be scheduled at midnight on June 30 or December 31.
Notification of
Leap Second Insertion
Your CDMA-synchronized Sonoma delivers very precise time and is generally troublefree. However,
when a leap second insertion is scheduled (about every three years), then you must manually program
the new leap seconds into your unit. You will have many months notice in which to do this. It is a
very simple procedure. See
Configure for Leap Second Event
below.
The International Earth Rotation Service (IERS) notifies the world of a pending leap second event
almost six months ahead of time. The EndRun Technologies’ website has a page devoted to notifying
users of the next leap second occurrence. This page will also tell you exactly what you need to do to
program the new leap seconds in your Sonoma. The appropriate link is:
http://www.endruntechnologies.com/leap.htm
If you wish to be notified by EndRun Customer Support when a leap second is pending, then send an
email request to support@endruntechnologies.com. Ask to be put on the leap second notification list.
Configure for
Leap Second Event
About once every three years you will need to program your Sonoma with new leap second informa-
tion. To view and change the leap second settings use commands
cdmaleapmode
and
cdmaleap-
config
. (See Chapter 9 - Console Port Control & Status .) Once you have programmed the unit for
the next leap second insertion you can forget about it. Since the values you set are stored in FLASH
memory, you can cycle power on your Sonoma with no problem.
The information at the website link shown above gives you details on programming the new leap
second information.
When the unit is configured at the factory prior to shipping, the current and future leap second values
are set appropriately for the next possible leap second insertion date (June 30th or December 31st).