Simchaev Arthur-BAS071 wrote:
Hi Guys
Thank you to your assistance . Seems is working now .
I see that NMEA chosen as PPS peer server :
remote refid st t when poll reach delay offset jitter
==============================================================================
oGPS_NMEA(0) .GPS. 0 l 12 16 377 0.010 -0.030 0.031.
But please clarify the following :
1) Can I sure that is update the system clock in PPS resolution
2) Why I still doesn't see PPSFREQ,PPSTIME,PPSSIGNAL , when I run ntptime .
My output is following :
ntptime
ntp_gettime() returns code 0 (OK)
time d6e78fed.18c23fa0 Thu, Apr 3 2014 7:44:45.096, (.096714581),
maximum error 3888 us, estimated error 474 us, TAI offset 0
ntp_adjtime() returns code 0 (OK)
modes 0x0 (),
offset 50.880 us, frequency -26.830 ppm, interval 1 s,
maximum error 3888 us, estimated error 474 us,
status 0x2001 (PLL,NANO),
time constant 4, precision 0.001 us, tolerance 500 ppm.
Hi
Above looks as if you are synced to NMEA rather than PPS.
What cpu, operating system and version are you using?
For NetBSD-6/i386 I have to use a custom kernel to enable PPS.
When I tried with Ubuntu-10/i386 I needed to install a pps package.
David
root@am335x-evm:/var/lib/ntp# ntpq -c as
ind assid status conf reach auth condition last_event cnt
===========================================================
1 65397 976a yes yes none pps.peer sys_peer 6
root@am335x-evm:/var/lib/ntp# ntpq -c "rv 65397"
associd=65397 status=976a conf, reach, sel_pps.peer, 6 events, sys_peer,
srcadr=GPS_NMEA(0), srcport=123, dstadr=127.0.0.1, dstport=123, leap=00,
stratum=0, precision=-20, rootdelay=0.000, rootdisp=0.000, refid=GPS,
reftime=d6e79065.fffb1778 Thu, Apr 3 2014 7:46:45.999,
rec=d6e79066.73ee526e Thu, Apr 3 2014 7:46:46.452, reach=377,
unreach=0, hmode=3, pmode=4, hpoll=4, ppoll=4, headway=0, flash=00 ok,
keyid=0, offset=0.054, delay=0.000, dispersion=0.262, jitter=0.031,
filtdelay= 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00,
filtoffset= 0.05 0.06 0.06 0.06 0.07 0.06 0.07 0.05,
filtdisp= 0.03 0.27 0.51 0.75 0.99 1.23 1.47 1.71
3) Since I can attach only one GPS to the board ntp.conf is following :
tos orphan 6
driftfile /var/lib/ntp/ntp.drift
server 127.127.20.0 minpoll 4 iburst #NMEA Server
fudge 127.127.20.0 flag1 1 flag2 0 time2 0.500
Regards
Arthur
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf
Of David Lord
Sent: Wednesday, April 02, 2014 11:25 PM
To: [email protected]
Subject: Re: PPS problem
David Lord wrote:
.....
I currently use a "Sure" gps, ntp-dev-4.2.7p433 on NetBSD-6
I have a few significant differences in my ntp.conf
#################
tos orphan 10
A few more comments
tos orphan 10 # is to replace your three lines:
server 127.127.1.0 #lo server
fudge 127.127.1.0 stratum 7
restrict 127.127.1.0 noquery nomodify notrap
tos mindist 0.4 # allows pps to kick in
^^^^^^^^^^^
server 127.127.20.2 mode 18
You can use this as prefer peer:
server 127.127.20.0 prefer
fudge 127.127.20.2 stratum 7 time2 0.407 flag1 0 refid GPSb
Required value for time2 will depend on your GPS model and firmware version.
server 127.127.22.2 minpoll 4 maxpoll 4 server 127.127.22.2 flag2 0
flag3 1 refid PPSb server -4 <ntp0.mydomain> server -4 <ntp1.myisp>
minpoll 8 maxpoll 10 iburst prefer
For what it's worth the last entry in my
/var/log/ntp-stat.20140402:
Wed Apr 2 17:36:00 GMT 2014
remote refid st t poll reach delay offset jitter
============================================================
-GPS_NMEA(2) .GPSb. 7 l 64 377 0.000 -1.940 8.828
oPPS(2) .PPSb. 0 l 16 377 0.000 0.000 0.004
+ns0.lordyne 81.187 3 u 64 377 1.363 -0.175 0.202
ns2.lordyne 192.16 2 u 64 377 0.498 -0.237 0.613
+ns1.lordyne 81.187 3 u 64 377 0.577 0.007 0.703
+ns3.lordyne 81.187 3 u 64 377 0.849 -0.486 0.690
*ntp1.xxxxxx 195.66 2 u 256 377 19.589 -0.943 0.403
associd=0 status=011d leap_none, sync_pps, 1 event, kern,
pll offset: -0.000317
pll frequency: -35.8115
maximum error: 0.406
estimated error: 3e-06
kernel status: pll ppsfreq ppstime ppssignal nano
pll time constant: 4
precision: 1e-06
frequency tolerance: 495.911
pps frequency: -35.8115
pps stability: 0.00480652
pps jitter: 0.002
calibration interval 256
calibration cycles: 6087
jitter exceeded: 7635
stability exceeded: 0
calibration errors: 20
ntp_adjtime() returns code 0 (OK)
modes 0x0 (),
offset -0.317 us, frequency -35.812 ppm, interval 256 s,
maximum error 406000 us, estimated error 3 us,
status 0x2107 (PLL,PPSFREQ,PPSTIME,PPSSIGNAL,NANO),
time constant 4, precision 0.001 us, tolerance 496 ppm,
pps frequency -35.812 ppm, stability 0.005 ppm,
jitter 1.500 us, intervals 6087, jitter exceeded 7635,
stability exceeded 0, errors 20.
David
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