[ntp:questions] Trimble Resolution SMT on Ubuntu 12.04

David Lord snews at lordynet.org
Fri Mar 30 15:58:31 UTC 2012


G wrote:
> update status for yesterday test:
> 
> #ntpq -p
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> xGPS_NMEA(1)     .GPS.            0 l    5    8  377    0.000  -256.03   3.906
> xtb.mircx.com    64.147.116.229   2 u   25   64  377   57.804  226.565  21.617
> 
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> xGPS_NMEA(1)     .GPS.            0 l    7    8  377    0.000  -249.14   3.906
> xtb.mircx.com    64.147.116.229   2 u   32   64  377   57.804  226.565  17.471
> 
> # ntptime
> ntp_gettime() returns code 0 (OK)
>   time d3202393.1dcde5c4  Fri, Mar 30 2012  8:20:35.116, (.116423510),
>   maximum error 1779138 us, estimated error 39027 us, TAI offset 0
> ntp_adjtime() returns code 0 (OK)
>   modes 0x0 (),
>   offset 0.000 us, frequency -92.524 ppm, interval 1 s,
>   maximum error 1779138 us, estimated error 39027 us,
>   status 0x2007 (PLL,PPSFREQ,PPSTIME,NANO),
>   time constant 3, precision 0.001 us, tolerance 500 ppm,
> # ntptime
> ntp_gettime() returns code 0 (OK)
>   time d3202394.eeafaafc  Fri, Mar 30 2012  8:20:36.932, (.932368988),
>   maximum error 1779638 us, estimated error 39027 us, TAI offset 0
> ntp_adjtime() returns code 0 (OK)
>   modes 0x0 (),
>   offset 0.000 us, frequency -92.524 ppm, interval 1 s,
>   maximum error 1779638 us, estimated error 39027 us,
>   status 0x2007 (PLL,PPSFREQ,PPSTIME,NANO),
>   time constant 3, precision 0.001 us, tolerance 500 ppm,
> 
> # ntpq -p
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> xGPS_NMEA(1)     .GPS.            0 l    6    8  377    0.000  -247.00   4.208
> xtb.mircx.com    64.147.116.229   2 u   39   64  377   57.804  226.565  17.471
> root at test12041:/home/ntp-4.2.6p5# ntpq -p
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> xGPS_NMEA(1)     .GPS.            0 l    -    8  377    0.000  -244.15   4.163
> xtb.mircx.com    64.147.116.229   2 u   57   64  377   57.804  226.565  17.471
> 
> root at test12041:/home/ntp-4.2.6p5# date
> Fri Mar 30 08:22:23 EDT 2012
> root at test12041:~# uname -a
> Linux test12041 3.2.0-17-generic-pae #27-Ubuntu SMP Fri Feb 24 15:59:25 UTC 2012 i686 i686 i386 GNU/Linux
> 
> I use ntp-4.2.6p5. should I try latest 4.2.7?
> 
> thanks your attention,
> 
> geng
> 
> 
> 
> 
> ----- Original Message -----
> From: G <geng_j at yahoo.com>
> To: Dave Hart <hart at ntp.org>
> Cc: "questions at lists.ntp.org" <questions at lists.ntp.org>
> Sent: Thursday, March 29, 2012 1:17 PM
> Subject: Re: Trimble Resolution SMT on Ubuntu 12.04
> 
> Dave,
> 
> thanks for your email. I change my conf as your suggest:
> -----------------------------------
> server 127.127.20.1 mode 18 prefer minpoll 3 maxpoll 3
> peer 0.ca.pool.ntp.org
> fudge 127.127.20.1 time2 0.0000
> fudge 127.127.20.1 flag1 1 flag3 1
> ----------------------------------------------------------------
> 
> and I link pps0 to gpspps1:
> ------------------------------------------
> #ln -s /dev/pps0 /dev/gpspps1
> 
> # ppstest /dev/gpspps1 
> trying PPS source "/dev/gpspps1"
> found PPS source "/dev/gpspps1"
> ok, found 1 source(s), now start fetching data...
> source 0 - assert 1333040090.999603804, sequence: 8631 - clear  0.000000000, sequence: 0
> source 0 - assert 1333040091.999709923, sequence: 8632 - clear  0.000000000, sequence: 0
> source 0 - assert 1333040092.999797692, sequence: 8633 - clear  0.000000000, sequence: 0
> source 0 - assert 1333040093.999884565, sequence: 8634 - clear  0.000000000, sequence: 0
> ----------------------------------------------
> also update system time before run ntpd:
> ----------------------------------------------------------
> root at test12041:~# ntpdate 0.ca.pool.ntp.org
> 29 Mar 10:28:42 ntpdate[1129]: adjust time server 129.128.5.210 offset -0.464322 sec
> root at test12041:~# ntpdate 0.ca.pool.ntp.org
> 29 Mar 10:28:52 ntpdate[1130]: adjust time server 209.167.68.100 offset -0.457408 sec
> root at test12041:~# ntpdate 1.ca.pool.ntp.org
> 29 Mar 10:29:06 ntpdate[1131]: adjust time server 216.194.70.2 offset -0.450851 sec
> --------------------------------------------------------------
> root at test12041:# ntptime
> ntp_gettime() returns code 0 (OK)
>   time d31ef2ca.2940fec0  Thu, Mar 29 2012 10:40:10.161, (.161148460),
>   maximum error 8043832 us, estimated error 34655 us, TAI offset 0
> ntp_adjtime() returns code 0 (OK)
>   modes 0x0 (),
>   offset -80566.987 us, frequency 21.606 ppm, interval 1 s,
>   maximum error 8043832 us, estimated error 34655 us,
>   status 0x2007 (PLL,PPSFREQ,PPSTIME,NANO),
>   time constant 3, precision 0.001 us, tolerance 500 ppm,
> 
> root at test12041:# ntpq -p
> 
> 
> 
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
>  GPS_NMEA(1)     .GPS.            0 l    -    8    0    0.000    0.000   0.000
>  caustique.anox. .INIT.          16 u    -   64    0    0.000    0.000   0.000
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> *GPS_NMEA(1)     .GPS.            0 l    2    8    7    0.000  -73.419  22.031
>  caustique.anox. .INIT.          16 u    -   64    0    0.000    0.000   0.000
> 
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> *GPS_NMEA(1)     .GPS.            0 l    5    8  377    0.000    4.693   3.906
>  caustique.anox. .INIT.          16 u    -   64    0    0.000    0.000   0.000
> root at test12041:/home/test# ntpq -p
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> *GPS_NMEA(1)     .GPS.            0 l    -    8  377    0.000    4.945   3.906
>  caustique.anox. .INIT.          16 u    -   64    0    0.000    0.000   0.000
> root at test12041:/home/test# ntpq -p
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> oGPS_NMEA(1)     .GPS.            0 l    2    8  377    0.000   -0.581   3.906
>  caustique.anox. .STEP.          16 u    - 1024    0    0.000    0.000   0.000
> 
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> oGPS_NMEA(1)     .GPS.            0 l    2    8  377    0.000    0.105   3.906
>  caustique.anox. .STEP.          16 u    - 1024    0    0.000    0.000   0.000
> 
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> oGPS_NMEA(1)     .GPS.            0 l    1    8  377    0.000    0.838   3.906
>  caustique.anox. 128.233.150.93   2 u  698 1024    1    5.516  994.460   3.906
> 
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> oGPS_NMEA(1)     .GPS.            0 l    7    8  377    0.000    1.849   3.906
>  caustique.anox. 128.233.150.93   2 u 1024 1024    1    5.516  994.460   3.906
> 
> 
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
> xGPS_NMEA(1)     .GPS.            0 l    5    8  377    0.000    1.460   3.906
> xcaustique.anox. 128.233.150.93   2 u 59  64   377    4.457 995.520   3.906
> 
> this is result for ntpd 3hours running .
> 
> I guess not good . I will let it run over night to see what change.
> 
> thanks,
> geng
> ----- Original Message -----
> From: Dave Hart <hart at ntp.org>
> To: G <geng_j at yahoo.com>
> Cc: "questions at lists.ntp.org" <questions at lists.ntp.org>
> Sent: Thursday, March 29, 2012 12:56 AM
> Subject: Re: Trimble Resolution SMT on Ubuntu 12.04
> 
> On Mon, Mar 26, 2012 at 16:06, G <geng_j at yahoo.com> wrote:
>> I use Trimble Resolution SMT to sync time for a Ubuntu 12.04 server (kernel 3.2.0).
>>
>> Trimble send NMEA to /dev/ttyUSB1(9600 8N1) on Ubuntu  server
>> PPS signal connect ACK pin on  /dev/parport0 . Ubuntu load Linux-PPS module( PPS_parport clear_wait=0) to create PPS device /dev/pps0
>>
>> I use verify the /dev/pps0  using rising edge by "ppstest /dev/pps0"
>> --------------------------------------------------------------------------------------------
>> trying PPS source "/dev/pps0"
>> found PPS source "/dev/pps0"
>> ok, found 1 source(s), now start fetching data...
>> source 0 - assert 1332775909.500413150, sequence: 249302 - clear  0.000000000, sequence: 0
>> source 0 - assert 1332775910.500456132, sequence: 249303 - clear  0.000000000, sequence: 0
>> source 0 - assert 1332775911.500499213, sequence: 249304 - clear  0.000000000, sequence: 0
>> -----------------------------------------------------------------------------------------------
>> To verify the NMEA message , I link /dev/ttyUSB1 to /dev/gps1
>> -----------------------------------------------------------------------------------------------
>> #cat /dev/gps1
>> $GPRMC,153343.000,A,4529.904930,N,07343.904831,W,0.241,325,260312,,,A*6F
>> $GPGGA,153344.000,4529.905010,N,07343.904879,W,1,3,3.17,12.368,M,-32.087,M,,*5E
>> ---------------------------------------------------------------------------------------------------
>> I create the /etc/ntp.conf:
>> -------------------------------------------------------------------------
>> server 127.127.20.1 mode 17 prefer       # NMEA RMC/GGA 9600bps
> 
> mode 17 is 16 (9600) plus 1 (select RMC)
> 
>> fudge 127.127.20.1 time2 0.01
>>
>> server 127.127.22.0 minpoll 4 maxpoll 4  # PPS ATOM
>> fudge 127.127.22.0 flag2 0 flag3 1
>>
>> driftfile /var/lib/ntp/ntp.drift
>> ------------------------------------------------------------------------------
>> after ntpd run 48hours, ntpq -p:
>>
>>      remote           refid     st t when poll reach   delay   offset  jitter
>> ==============================================================================
>> xGPS_NMEA(1)     .GPS.            0 l   44   64  377    0.000  -214.54  25.464
>> xPPS(0)          .PPS.            0 l   11   16  377    0.000  -174.60   4.981
>>
>>
>> I have no idea why I got this result . what do I miss for config? by the way , I compile ntpd from source , not using ntpd from Ubuntu.
> 
> I'm not sure why you're seeing that result.  First, flag3 1 doesn't
> appear to be working, in that the offset of the PPS is far away.
> Moreover, when  feasible I suggest using NMEA's built-in PPSAPI
> support.  You should be able to to remove the PPS refclock and add
> flag1 1 to the fudge 127.127.20.1 line, then add a soft link from
> /dev/gpspps1 to /dev/pps0.  This eliminates the risk of two clocks
> whose confidence intervals don't overlap both being tossed as
> falsetickers, as your PPS will be provided via the same refclock.
> 
> Good luck,
> Dave Hart
> _______________________________________________
> questions mailing list
> questions at lists.ntp.org
> http://lists.ntp.org/listinfo/questions

Hi

I'm on NetBSD-5 and don't have much experience with PPS on
Ubuntu LTS 10.4 that I use.

When I updated ntpd on NetBSD to 4.2.6p5 the ATOM driver I'd
previously used (as from 2009) was no longer working and was
marked as falseticker although it was obviously really working
with offset of a few microsecond same as with 4.2.6p3

I'd suggest to add some pool or local servers to ntp.conf and to
use noselect option for 127.127.20.2 and log offset to determine
reasonable value for fudge time2.

If you need to use 127.127.22 driver I'd suggest to use ntpd
v4.2.6p3. I don't know if parallel port pps works with the type
20 driver.

############################
# v4.2.6p3 through February 2012
tos             minsane 3  orphan 10  mindist 0.5
server 127.127.20.2 mode 18 prefer
fudge  127.127.20.2 time2 0.350 refid GPSb
server 127.127.22.2
fudge  127.127.22.2 flag2 0 flag3 1 refid PPSb
peer    <local server-1>                 minpoll 6   maxpoll  8  iburst
server  <local server-2>                 minpoll 6   maxpoll  8  iburst
server  <local server-3>                 minpoll 6   maxpoll  8  iburst
server  <public server-4>                minpoll 9   maxpoll 11  iburst
server  <public server-5>                minpoll 9   maxpoll 11
############################
# v4.2.6p5 from March 2012
tos             minsane 3  orphan 10  mindist 0.3
server 127.127.20.2 mode 18
fudge  127.127.20.2 time2 0.410 flag1 1  flag2 0  flag3 1  refid GPSb
peer    <local server-1>             minpoll  6  maxpoll 10  iburst
peer    <local server-2>             minpoll  6  maxpoll 10  iburst
server  <local server-3>             minpoll  8  maxpoll 10  iburst
server  <local server-4>             minpoll  8  maxpoll 10  iburst
server  ntp1.lordynet.org            minpoll  8  maxpoll 10  iburst
server  ntp0.lordynet.org.uk         minpoll  8  maxpoll 10  iburst
############################


best of luck.


David



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