> Le 18 nov. 2017 à 22:55, William Unruh <un...@invalid.ca> a écrit : > > I am having sudden problems on my system with a Sure GPS with PPS. > I am running chrony, using a serial port to bring in the PPS signal. > Everything was working well-- the rms timing on the pulse was about 1usec. > Suddenly on Nov 18 at very close to 00:00:00UTC the timing went to hell, and > the > rpms is now at 20us-- the individual pulses have an offset that fluctuates > between about 50us, and -50us.
I can just report that I didn’t see any issues with my Sure board at that time. I am getting 1-5us offset reported by NTP pretty much stable all day. > Is there any hint as to what I could do to track down the problem. Could it be > the sattelites (ie the timing has suddenly gone from ns to tens of usec for > some reason? But if this were true I would have expected to hear many many > loud screams here.) Or the gps receiver? (again, unlikely I would think). Or > the serial card? or chrony? Or the computer clock? (the computer was not > rebooted anywhere around that date). Have you checked the antenna. I had one of mine fall off the window ledge which didn’t help. Have you power cycled the receiver? That may kill it, but at least you will know. If you have another computer, connect it to that to see if the problem follows. You could configure it as « noselect » (if possible in chrony) and see if the clock drift is erratic. Borrow an oscilloscope and check the raw PPS signal. If you have a second PPS source, check your config with that in place of the Sure board. > : > By the way, what in the world has happened to this newsgroup? I am getting > about 1 valid message to over 100 Case Solutions? Its very low traffic . Maybe we are considered dummies. > > _______________________________________________ > questions mailing list > questions@lists.ntp.org > http://lists.ntp.org/listinfo/questions "The power of accurate observation is commonly called cynicism by those who have not got it. » George Bernard Shaw _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
