[ntp:questions] Win7 NTP-dev NMEA User Mode PPS, Freq_Mode Not Working

David Taylor david-taylor at blueyonder.co.uk.invalid
Thu Feb 27 12:21:13 UTC 2014

On 27/02/2014 08:37, Brian Inglis wrote:
> Hi folks,
> Tried testing latest NTP-dev 4.2.7p424 from DJT site on Windows 7 x64
> with UTC RTC
> and Garmin 18x LVC with DCD PPS sending RMC only in NMEA 2.3+ mode @ 9600.
> NTPd running at realtime priority affinity set to processor 3 with both
> dev and stable.
> NMEA user mode PPS timestamp never reported - works fine on stable
> before and after dev test.
> Freq_Mode never reported - works fine on stable before and after dev test.
> Frequency and offset ran away with no sign of return towards hardware
> drift of +0.9PPM.
> Leap_Event reported on ntpq -c rv instead of Clock_Sync.
> Event c016 06 restart reported in log after c012 02
> freq_set on dev
> but vice versa order on stable.
> Event c615 05 clock_sync reported in log 30s after c61c
> 0c clock_step on dev
> c614 04 freq_mode reported in log 30s after c61c 0c
> clock_step on stable,
> but on stable c412 02 freq_set then c415 05 clock_sync
> reported 15mins later.
> Anyone any ideas what might be causing this/these discrepancies between
> dev and stable?


I don't know whether it helps, but I see this on a Windows-8.1/64 PC 
running the signed kernel-mode PPS driver.  It's a GPS 18x LVC which is 
driving it, powered of 5V from a USB port.  I don';t know at the moment 
what the Garmin is set to output.  It's on the latest firmware: 3.90. 
Realtime priority (set by the program) and affinity mask is for all rour 
processors (i5-3330 chip).

C:\Users\David>ntpq -crv stamsund
associd=0 status=0115 leap_none, sync_pps, 1 event, clock_sync,
version="ntpd 4.2.7p424 at 1.2483-o Feb 24 10:38:46.00 (UTC-00:00) 2014  (1)",
processor="x86", system="Windows", leap=00, stratum=1, precision=-22,
rootdelay=0.000, rootdisp=1.120, refid=PPS,
reftime=d6b9a9e9.bb0f6f05  Thu, Feb 27 2014 12:11:21.730,
clock=d6b9a9f1.d7ef24ca  Thu, Feb 27 2014 12:11:29.843, peer=18499, tc=4,
mintc=3, offset=0.019701, frequency=-6.425, sys_jitter=0.013465,
clk_jitter=0.020, clk_wander=0.000, tai=35, leapsec=201207010000,

Sorry for the wrap!

General performance of that PC is here:


Not sure how to proceed, but if I can be of help, I will.

Web: http://www.satsignal.eu

More information about the questions mailing list