Update Leap Seconds File - Safran WR-Z16 User Manual

5.8.1

Update Leap Seconds File

Besides using 10MHz & PPS signals from the front- panel, the GM time source
needs to obtain the Time of Day (ToD) from an external reference. NTP is com-
monly used because of its easy configuration. However, the leap seconds must
be properly handled. Indeed, NTP is based on UTC timescale whereas PTP is
based on TAI and thus the non-fixed offset between UTC-TAI is provided by the
leap second file which varies according to earth rotation.
This file (also known as Bulletin C) is published by the International Earth Rota-
tion and Reference Systems Service (IERS) every six months to tell if a leap
second jump is scheduled for the end of next June or December, or not. This also
means that the file shipped within the release has an expiration date and does not
guarantee a valid UTC-TAI conversion after this date.
In order to always ensure a correct UTC-TAI correction, the device that can act as
Grand-Master on the network, can also manually update this file through the Con-
figuration > Misc panel:
Figure 5-19:
CHAPTER •
5 WR-Z16 User Manual Rev. v5.0
Manual Leap seconds update.
Note: Updating the leap seconds file can be performed hot by apply-
ing the configuration, so there is no need to reboot.
5.8 Miscellaneous
95