[ntp:questions] How to determin hardware latency for PPS offset given simple tools.

Paul G bodosom at gmail.com
Fri May 24 20:28:19 UTC 2013


I have four GPS receivers into four different computers.  I've assumed that I
should be able to get small offsets between them but to do so I need
to set time1.  If that's the correct approach how do I pick the "right"
system to be the benchmark.  So far I've just been assuming that
the purpose built M. Tharp server should have the lowest latency but I'm not sure -- in any case, at present, I can't adjust it.

Each machine in the truncated table below (except 210) has a time1
value derived in an ad hoc fashion.

l     r    refid       st   delay   offset  jitter
==================================================
1   o22.0  .PPS.        0   0.000   -0.001   0.001
2   +244   .PPS.        1   0.068    0.000   0.006
2   *210   .GPS.        1   0.514   -0.008   0.136
2   +192   .PPS.        1   0.455    0.008   0.032


I feel as if this topic should be clearly explained somewhere but I've been
unable to find it.



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