Installation & Operation Manual TCC70XS
Page 50
3.2.8.2 Handling a Leap Second
The NTP server basically works with
UTC
, so it is not affected by any DST switching of a local
time zone, but it is affected by a time jump according to a leap second.
NTP itself does not provide any special leap second handling. You will find a lot of information
on this issue in the Internet.
Please also refer to the document “Leap Second and Time Code”, available at:
A real
–
time reference (which is either an external real
–
time reference at the REF/GPI connector
or the NTP client) will be responsible for the accuracy of the NTP server of TCC70XS.
If a leap second announcement from the real
–
time reference is received, a leap second alarm
will be transmitted to the NTP server. Normally, this alarm will be raised 55 minutes before the
event.
NTP messages include a leap indicator (
LI
). This way, a leap second alarm can be transported
from NTP server via NTP clients to the operating system, which then can use this information
for a leap second handling.
You can check your NTP connection and the leap second announcement with
NTP Tool
by
Plura, available at:
Example: The “
Leap Indicator
”
status announces a leap second:
