| Re: [chrony-users] Setting up Chrony with PPS |
[ Thread Index |
Date Index
| More chrony.tuxfamily.org/chrony-users Archives
]
- To: chrony-users@xxxxxxxxxxxxxxxxxxxx
- Subject: Re: [chrony-users] Setting up Chrony with PPS
- From: Deven Hickingbotham <devenh@xxxxxxxxxxx>
- Date: Sat, 20 Feb 2016 18:48:29 -0800
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pacbell.net; s=s2048; t=1456022889; bh=5MKov4fg4gAAX4x81bvlPA6G4VVUR/oYgyDd8mRjgHU=; h=Subject:To:References:From:Date:In-Reply-To:From:Subject; b=dVatYRJVuo9N4pRjPRU1+53BkmCxdsMUHcQ6DlWKkgZJeZ3uiKJpLuKpQ7qxDCNMu/j8mQE7IHa/ZieER00clRWUxJixdoHpT2IRZXk1iKoLrpvgNpO/X0JKy+9rGxFqY0z52ySbOPBhpxx53OXO/OS+bEOWvG9btnlQyX09/TNtmoRO9/QFEPHCBNbksgfCZtH9A8cTYZSDpug9W0tz7h3GFPysfvldXCz9YG4AFBP8KKbGNF3gclAo7kjdNFl7AZNIXbLg/NNvfo8h5HuSHfCgmnC1Uhb8V0CEgvUXgDi6zExoKaM43jLamcGsS/EZDqxOeLNCVAwr5GOF6hgZHQ==
Hi Bill,
On 2/20/2016 5:13 PM, Bill Unruh wrote:
I am really worried about your scatter for the PPS, as I was for the
scatter
in your assert line. You should NOT be getting a 7ms uncertainty in PPS. It
should be more like 7us-- ie 1000 times better. There is something wrong.
Either your gpio do not raise interrupts and are being read by very bad
polling, or there is something very wrong with your GPS. I also cannot
understand your HORRIBLE offsets from external sources ( 1.3
seconds out) That is absurd. It looks to me like your NMEA is way out as
well. YOur GPS is a piece of junk it looks like.
I have an identical system and will replicate the tests on that unit. I
don't have that system right now, but I'll post results on Monday or
Tuesday.
And destroy your filesystem in the process? The system does not like
jumps in
time. You can do it at startup of chrony (the -r option) but that should
not
happen after the system has been running, or things could get upset.
Oh, I don't want to do that. But I would like to configure chrony so
that it quickly adjusts. Quickly being 20 minutes.
The system chrony is running on will not be a time server for any other
systems. The app I'm writing that runs on the system simply needs the
most accurate time to within +/- 5ms. So while I agree with you that
PPS should be delivering much better accuracy, 7321us is pretty close to
what I need.
Deven
--
To unsubscribe email chrony-users-request@xxxxxxxxxxxxxxxxxxxx
with "unsubscribe" in the subject.
For help email chrony-users-request@xxxxxxxxxxxxxxxxxxxx
with "help" in the subject.
Trouble? Email listmaster@xxxxxxxxxxxxxxxxxxxx.