[ntp:questions] ntp.conf file setup in netbsd
anur55 at gmail.com
Tue Jul 14 20:50:21 UTC 2009
Thank you very much for your help. Apparently, netbsd 5.0 still doesn't
support GPZDA string so when i enabled the GPGGA string which was initially
disabled in our system, the serial port was able to read nmea and pps
signals and is able to synchronize the two signals. I found the kernel
PPS_SYNC option giving more stable and accurate values more than enabling
PPS driver. Thank you very much for your help I appreciate it : )
On Mon, Jul 13, 2009 at 10:13 AM, Daniel Hagerty <hag at linnaean.org> wrote:
> For the list: netbsd 5.0's ntpd looks to be 4.2.4p6 (gleaned from
> Runa Dahal <anur55 at gmail.com> writes:
> > I am using NetBSD 5.0 operating system in a low powered embedded computer
> > used solely for the purpose of NTP. I have enabled options PPS_SYNC
> > in the kernel and rebuilt it. My ntp.conf file has the following set up:
> I'm using approximately the following on netbsd-4.0 with a NMEA
> GPS emitting GPGGA sentences:
> server 127.127.20.1 mode 2 prefer
> fudge 127.127.20.1 flag3 1
> server 127.127.22.1
> fudge 127.127.22.1 flag3 1 refid GPS
> NetBSD 4.0's ntpd is too old to support GPZDA. A quick reading of
> the source for netbsd 5.0's ntpd suggests no improvement in this
> Even if your ntpd supports it, you'll need to replace the "mode 2"
> I use above with a "mode 8".
> > I have a couple questions regarding NMEA PPS. If I am using kernel PPS
> > discipline, then do I not need to specify ntpd atom pps(22) driver? I
> know I
> > need to have flag3 1 flag. Can I use ntpd PPS driver instead of kernel
> > even with NetBSD being compiled PPS_SYNC, so, that I could easily switch
> > being either for testing. Do I always need to specify flag1 1 since I
> > PPS ?
> You can have a kernel with PPS_SYNC where ntpd doesn't use it.
> Just drop the "flag3 1" options from the nmea and pps drivers.
> I spent some time experimenting myself to come up with what I'm
> currently using, and wasn't about to reboot to do it :)
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