[LinuxPPS] Synchronizing a ZDA message with NTP using linuxPPS

[Udo van den Heuvel]

On 2010-03-20 18:52, Divi.Oillo at ifremer.fr wrote:
> I have change ntp.conf:
> #use only pps
> server ntpserver minpoll 4 maxpoll 4
> fudge 127.127.22.0 flag2 1

What is the `ntpserver`?
Please use the numbers, else I cannot see what the fudge applies to.


> techsas:~> cat /sys/devices/virtual/pps/pps0/assert
> 1269101302.889573228#1710
> techsas:~> cat /sys/devices/virtual/pps/pps0/assert
> 1269101332.889534748#1740
> techsas:~> cat /sys/devices/virtual/pps/pps0/assert
> 1269101335.889533533#1743

Looks good.

> 
> techsas:~> ntpq -p
>       remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> *ntpserver       .1PPS.           1 u    4   16  377    0.163    1.023   0.384
> 
> So does it mean that PPS works with ntpserver?

Assuming that the server is the one you mentioned earlier then the
server is working OK.
But I cannot tell for sure. Please use `ntpq -pn`.

As I do not see the local clock.
E.g.:
 ntpq -pn
     remote           refid      st t when poll reach   delay   offset
jitter
==============================================================================
 127.127.1.0     .LOCL.          15 l   42   64  377    0.000    0.000
 0.002
+127.127.20.0    .GPS.           14 l    2   16  377    0.000   -0.009
 0.002
o127.127.22.0    .PPS.            0 l    -   16  377    0.000   -0.009
 0.002
+194.109.22.18   193.67.79.202    2 u   57   64  377   15.989   -2.835
 1.377


The top 3 clocks are the local 'dummy' clock, a NMEA clock and a PPS
clock (for the same hardware).


Udo