81–90 of 162 posts
Are there any plans being made to prevent this happening in the future?
Yes, the US government is banning all those democrat windmills that conspired to blow over the NTP server.
Nitpick: UTC stands for Coordinated Universal Time. The ordering of the letters was chosen to not match the English or the French names so neither language got preference.
> The official abbreviation for Coordinated Universal Time is UTC. This abbreviation comes as a result of the International Telecommunication Union and the International Astronomical Union wanting to use the same abbreviation in all languages. The compromise that emerged was UTC, which conforms to the pattern for the abbreviations of the variants of Universal Time (UT0, UT1, UT2, UT1R, etc.).
Earlier quoted context omitted.
We don't use NTP, but for robotics, stereo camera synchronization we often want the two frames to be within ~10us of eachother. For sensor fusion we then also need a lidar on PTP time to be translated to the same clock domain as cameras, for which we also need We actually disable NTP entirely (run it once per day or at boot) to avoid clocks jumping while recording data.
In your stereo camera example, are these like USB webcams or something like MIPI CSI attached devices?
Earlier quoted context omitted.
We don't use NTP, but for robotics, stereo camera synchronization we often want the two frames to be within ~10us of eachother. For sensor fusion we then also need a lidar on PTP time to be translated to the same clock domain as cameras, for which we also need We actually disable NTP entirely (run it once per day or at boot) to avoid clocks jumping while recording data.
> We actually disable NTP entirely (run it once per day or at boot) to avoid clocks jumping while recording data. This doesn't seem right to me. NTP with default settings should be monotonic. So no jumps. If you disable it Linux enters 11-minute mode, IIRC, and that may not be monotonic.
In our case the jumps where because we also have PTP disciplining the same system clock, when you have both PTP and NTP fighting over the same clock, you will see jumping with the default settings.
For us it was easier to just do a one time NTP sync at the beginning/boot, and then sync the robots local network with only PTP afterwards.
Are there any plans being made to prevent this happening in the future?
Yes, the US government is banning all those democrat windmills that conspired to blow over the NTP server.
Earlier quoted context omitted.
> Gah, just when you think you can trust time.nist.gov You still can... If you're that considered about 5 microseconds: Build your own Stratum 1 time server https://github.com/geerlingguy/time-pi or just use ntppool https://www.ntppool.org/en/
It sounds like GPS, and thus a GPS-based stratum 1 server, uses these time servers, but they were successfully failed over: > Jeff finished off the email mentioning the US GPS system failed over successfully to the WWV-Ft. Collins campus. So again, for almost everyone, there was zero issue, and the redundancy designed into the system worked like it's supposed to. So failures in these systems are potentially correlate…
Nitpick: UTC stands for Coordinated Universal Time. The ordering of the letters was chosen to not match the English or the French names so neither language got preference.
That doesn't quite match what the wikipedia page says: > The official abbreviation for Coordinated Universal Time is UTC. This abbreviation comes as a result of the International Telecommunication Union and the International Astronomical Union wanting to use the same abbreviation in all languages. The compromise that emerged was UTC, which conforms to the pattern for the abbreviations of the variants of Universal Tim…
> ... in English the abbreviation for coordinated universal time would be CUT, while in French the abbreviation for "temps universel coordonné" would be TUC. To avoid appearing to favor any particular language, the abbreviation UTC was selected.
Out of curiosity, can anyone say the most impactful things they've needed incredibly accurate time for?