[ntp:questions] Peer Review of ntpq -c rv

David Lord snews at lordynet.org
Thu Mar 8 12:28:07 UTC 2012


Ron Frazier (NTP) wrote:
> On 3/7/2012 7:10 PM, David Lord wrote:
>> Ron Frazier (NTP) wrote:
>>> I'm a little confused.  Are you currently getting offsets in the 10's 
>>> of milliseconds range or in the 10's of microseconds range.  Also, 
>>> how are you measuring offset from UTC, as opposed to offset from the 
>>> GPS board?
>>>
>>> Sincerely,
>>>
>>> Ron
>>>
>>>
>>> On 3/7/2012 7:26 AM, Alby VA wrote:
>>>>   I'm looking to get a little feedback on if the following output of my
>>>> Sure GPS / FreeBSD
>>>> setup looks like its running smoothly and keeping time correctly.
>>>>
>>>>
>>>> assID=0 status=0115 leap_none, sync_atomic, 1 event,
>>>> event_clock_reset,
>>>> version="ntpd 4.2.6p5 at 1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)",
>>>> processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1,
>>>> precision=-19, rootdelay=0.000, rootdisp=0.269, refid=PPS,
>>>> reftime=d301d22f.dc1393c2  Wed, Mar  7 2012  7:25:19.859,
>>>> clock=d301d230.cc08bad9  Wed, Mar  7 2012  7:25:20.797, peer=41909,
>>>> tc=4, mintc=3, offset=-0.034, frequency=-25.214, sys_jitter=0.002,
>>>> clk_jitter=0.002, clk_wander=0.001
>>
>> From above the offset is -0.034 msec, ie 34 usec
>>
>>
>> David
>>
> 
> At first I was confused and thought he was ms off.  However, if he's 
> within 34 us, that's pretty good.  Sounds like his board is working OK, 
> but could possibly be a bit better.  If he were communicating 
> exclusively on the serial port and the PPS were not working, would he be 
> getting performance this good?
> 

My system with Sure GPS and PPS :
ident            mean    rms    max
127.127.22.2    0.000  0.004  0.030

The 30 usec offsets are during the morning at time the
system logs are created and rotated.

I'll try to insulate the xtal when I next have to move
the pc but I don't know that the blips in offset are
caused by increase in temperature.


David



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