[Linuxpps] Duplicated sequence numbers

[Adam James]

On Tue, 30 May 2006 00:13:45 +0200
Rodolfo Giometti <giometti at linux.it> wrote:

> On Mon, May 29, 2006 at 10:37:12PM +0100, Adam James wrote:
> > 
> > Perhaps you could also advise as to whether the following ppstest
> > output is a bug or a problem with my system (notice the duplicated
> > sequence numbers):
> > 
> > # ./ppstest
> > found PPS source #0 "pps_8250_0" on "/dev/ttyS0"
> > Assert timestamp: 1148936547.001043675, sequence: 2285
> > Assert timestamp: 1148936547.001043675, sequence: 2285
> > Assert timestamp: 1148936548.001042675, sequence: 2286
> > Assert timestamp: 1148936548.001042675, sequence: 2286
> > Assert timestamp: 1148936549.001045675, sequence: 2287
> > Assert timestamp: 1148936549.001045675, sequence: 2287
> 
> I just modified the ppstest program, now it displays both assert and
> clear fileds. Please, try this new version.
> 
> Ciao,
> 
> Rodolfo

Thanks for your remarkably quick reply, it is much appreciated!

I now get the following output from ppstest:

# ./ppstest
found PPS source #0 "pps_8250_0" on "/dev/ttyS0"
assert 1148941843.001278000, sequence: 7357 - clear  1148941843.101270000, sequence: 7357
assert 1148941844.001280675, sequence: 7358 - clear  1148941843.101270000, sequence: 7357
assert 1148941844.001280675, sequence: 7358 - clear  1148941844.101272000, sequence: 7358
assert 1148941845.001293675, sequence: 7359 - clear  1148941844.101272000, sequence: 7358
assert 1148941845.001293675, sequence: 7359 - clear  1148941845.101272000, sequence: 7359
assert 1148941846.001297675, sequence: 7360 - clear  1148941845.101272000, sequence: 7359
assert 1148941846.001297675, sequence: 7360 - clear  1148941846.101274000, sequence: 7360
assert 1148941847.001278675, sequence: 7361 - clear  1148941846.101274000, sequence: 7360
assert 1148941847.001278675, sequence: 7361 - clear  1148941847.101275000, sequence: 7361

As the timestamps are duplicated along with the sequence numbers, I
presume that the PPS signal is being received correctly.

Could you shed any light on the following message output by ntpd:

ntpd[7024]: refclock_nmea: time_pps_kcbind failed: Operation not supported

Is this a limitation of the current implentation, on a problem at my
end?

Thanks once again.

--Adam