[ntp:questions] Second attempt at GPS-18 based NTP server
Kenyon Ralph
kenyon at kenyonralph.com
Wed Feb 8 19:22:13 UTC 2012
On 2012-02-03T15:55:41-0000, David J Taylor <david-taylor at blueyonder.co.uk.invalid> wrote:
> >The need to make a custom kernel that includes option PPS_SYNC is
> >still true on the recently released FreeBSD 9.0.
> >
> >Tom
>
> Thanks, Tom. I'm not familiar with FreeBSD 8.0, but looking at the
> revision dates on some files it appears that I /may/ have recompiled
> the kernel. Difficult for me to tell, though. This is what I see:
>
> ______________________________
> C:\>ntpdc -c kerninfo pixie
> pll offset: -0.00234 s
> pll frequency: 27.835 ppm
> maximum error: 0.008483 s
> estimated error: 2e-006 s
> status: 2107
> pll time constant: 4
> precision: 1e-006 s
> frequency tolerance: 496 ppm
> pps frequency: 27.835 ppm
> pps stability: 0.007 ppm
> pps jitter: 0.00274 s
> calibration interval: 256 s
> calibration cycles: 160784
> jitter exceeded: 30488
> stability exceeded: 0
> calibration errors: 11
> ______________________________
>
> C:\>ntpq -p pixie
> remote refid st t when poll reach delay
> offset jitter
> ==============================================================================
> *GPS_NMEA(1) .PPS. 0 l 6 16 377 0.000
> 0.001 0.004
> -odie.tomelliott 158.43.128.33 2 u 746 1024 377 23.658
> 3.961 7.972
> -dnscache-london 140.203.204.77 2 u 845 1024 377 27.784
> 0.433 18.409
> 195.66.148.150 140.203.204.77 2 u 370d 1024 0 25.383
> 3.955 0.000
> ______________________________
>
>
> so perhaps I did. I don't see the "o" of the Atom driver, though.
I don't think you're using the kernel PPS signal, so you may not have
compiled the kernel with the PPS_SYNC option. This is what you should
see, notice the "o" and mentions of PPS in kerninfo output (this
output is from my system at gauss.kenyonralph.com):
% ntpq -p -c clockvar -c readvar -c kerninfo
remote refid st t when poll reach delay offset jitter
==============================================================================
oGPS_NMEA(0) .GPS. 0 l 2 8 377 0.000 0.000 0.001
+darwin.kenyonra 127.67.113.92 2 u 44 64 377 21.390 2.368 2.346
voodoo.kenyonra 94.78.119.192 2 u 42 64 377 0.266 -0.049 0.101
grunt.kenyonral 94.78.119.192 2 u 23 64 377 0.177 0.338 0.137
+clock.fmt.he.ne .CDMA. 1 u 52 64 377 21.849 2.738 4.929
*tick.ucla.edu .GPS. 1 u 5 64 377 31.669 2.297 2.449
+2607:fa18::2407 .GPS. 1 u 26 64 377 42.877 2.162 2.844
+ntp.exact-time. .GPS. 1 u 53 64 377 204.112 0.845 4.218
+ntp.your.org .CDMA. 1 u 39 64 377 73.350 1.922 3.373
-otc2.psu.edu 189.122.110.167 2 u 26 64 377 104.273 4.057 5.620
+ntp2.jtsage.com 127.67.113.92 2 u 33 64 377 60.318 0.887 1.376
+tick.e.mattnord 129.7.1.66 2 u 56 64 377 60.775 0.466 1.532
associd=0 status=0000 no events, clk_unspec,
device="NMEA GPS Clock",
timecode="$GPGGA,191413,3259.1559,N,11714.2879,W,1,07,1.6,126.8,M,-35.3,M,,*79",
poll=48532, noreply=0, badformat=0, baddata=0, fudgetime2=600.000,
stratum=0, refid=GPS, flags=5
associd=0 status=0415 leap_none, sync_uhf_radio, 1 event, clock_sync,
version="ntpd 4.2.7p255 at 1.2483-o Sat Feb 4 07:17:31 UTC 2012 (1)",
processor="amd64", system="FreeBSD/9.0-STABLE", leap=00, stratum=1,
precision=-20, rootdelay=0.000, rootdisp=1.060, refid=GPS,
reftime=d2dd4801.c5aa4064 Wed, Feb 8 2012 11:14:09.772,
clock=d2dd4806.88e99e3f Wed, Feb 8 2012 11:14:14.534, peer=42035, tc=3,
mintc=3, offset=-0.000, frequency=-4.149, sys_jitter=0.001,
clk_jitter=0.001, clk_wander=0.001
associd=0 status=0415 leap_none, sync_uhf_radio, 1 event, clock_sync,
pll offset: -0.002731
pll frequency: -4.14865
maximum error: 0.0035
estimated error: 0
kernel status: pll ppsfreq ppstime ppssignal nano
pll time constant: 3
precision: 1e-06
frequency tolerance: 495.911
pps frequency: -4.14865
pps stability: 0.00845337
pps jitter: 0.002
calibration interval 256
calibration cycles: 3295
jitter exceeded: 14137
stability exceeded: 0
calibration errors: 8
--
Kenyon Ralph
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