[ntp:questions] Second attempt at GPS-18 based NTP server

A C agcarver+ntp at acarver.net
Thu Feb 2 21:06:09 UTC 2012


On 2/2/2012 02:02, Paul Duncan wrote:

> Please note, I have not done any recompiling of the kernel at this stage
> - just using the GENERIC kernel, because after reading the comments from
> Per Hederland in the System software customisation section of the above
> web page, it seemed unnecessary. Comments?

Sent the first email accidentally before I finished.

The generic BSD kernel does not enable PPS support by default.  You must 
recompile to enable PPS.


The page you quoted says the following the section "System software 
customization" (about 45% down the page in the Software section):

System software customisation

Need to add one line to the Kernel configuration:

     options PPS_SYNC

and recompile the Kernel.  On my 133MHz/48MB system this can take 
several hours.  Note the configuration suggestions below before you 
recompile the kernel.



It does appear that your system sees PPS though it hasn't synced to it 
yet (there's no indicator in the first column).  However, I haven't been 
able to use PPS unless I enable PPS in the kernel.  Try it in the 
current configuration and see how it works.  Then if you feel like it 
try again with PPS_SYNC enabled and see what happens.

I'm using NetBSD (though on sparc hardware not x86 so serial ports 
behave a bit differently) and I do have PPS_SYNC enabled in the kernel. 
  I am bringing in PPS to ntpd via the PPS refclock because the GPS is 
using SiRF binary not NMEA.

>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> o127.127.22.0    .PPS.            0 l   13   16  377    0.000    0.004   0.061
>  127.127.28.0    .GPSD.           0 l   81  128  377    0.000  -32.127   6.525
> +207.7.148.214   216.218.254.202  2 u    4  512  377   40.196    0.655   0.247
> +72.14.179.211   216.218.254.202  2 u   16  512  377   57.519   -0.108   0.377
> +173.255.224.22  64.90.182.55     2 u  389  512  377   93.350   -0.281   1.096
> *130.207.165.28  130.207.244.240  2 u  140  512  377   94.450   -5.508   0.301
> +131.144.4.10    130.207.244.240  2 u  220  512  377   87.476    3.088   2.851

(I hope mine stays running for longer than five days, I'm on day two 
after a restart of ntpd.)


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