[ntp:questions] ntptime didn´t show ppssignal

Burkhardt, Frank frank.burkhardt at fokus.fraunhofer.de
Mon Aug 23 12:30:19 UTC 2010

Dear Listmembers,

first of all sorry for my bad english, but I'm not a native speaker and not trained so well ;-)

I tried to get ntpd working with a pps signal (atom driver) under Ubuntu 10.04 since one week without success. I'm using a self compiled kernel with pps support and pps_client ldisc built in. "pstest" shows following data, so I think it is generally working:

root at chaser:/home/fast# /export/pps-tools/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 1282565685.198781684, sequence: 352669 - clear  1282213025.923967757, sequence: 10
source 0 - assert 1282565686.198843801, sequence: 352670 - clear  1282213025.923967757, sequence: 10
source 0 - assert 1282565687.198921096, sequence: 352671 - clear  1282213025.923967757, sequence: 10

I compiled ntpd with --enable-atom option, but when I start ntpd it shows following error in the log:

16 Aug 10:36:00 ntpd[17210]: refclock_newpeer: clock type 22 invalid
16 Aug 10:36:00 ntpd[17210]: interface -> (null)

But i think the problem has maybe nothing to do with ntpd directly so far, because ntptime shows only PLL, NANO and not PPSXXXX in the status field: 

ntp_gettime() returns code 0 (OK)
  time d01ce7a9.c30c885c  Mon, Aug 23 2010 14:27:21.761, (.761910415),
  maximum error 257004 us, estimated error 458 us
ntp_adjtime() returns code 0 (OK)
  modes 0x0 (),
  offset -42.572 us, frequency 17.326 ppm, interval 1 s,
  maximum error 257004 us, estimated error 458 us,
  status 0x2001 (PLL,NANO),
  time constant 6, precision 0.001 us, tolerance 500 ppm

So is the kernel not detecting the PPS, even though ppstest shows the signal etc.?

I don´t know how I can proceed, miss I something else, do someone have any hints for me?

Many thanks in advance and kind regards from Berlin,

Frank Burkhardt                         Fraunhofer FOKUS
Dipl.-Kfm.                              Forschungsinstitut für Offene
Network research                        Kaiserin-Augusta-Allee 31
                                        10589 Berlin
Tel.: 030-34 63-71 88                   Tel.: 030-34 63-70 00
Fax:  030-34 63-81 88                   Fax:  030-34 63-80 00

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