[LinuxPPS] ntpd doesn't recognize my PPS signal

[Luca Bertagnolio]

Thorsten,

the ppstest logs show that LinuxPPS seems to be working well.  You
have a 100ms pulse out of your PPS device.

The "doubled" sequence numbers are related to the fact that each
change of the pulse status prints the last assert and clear, if you
check carefully your ppstest log you will see the timestamp reported
twice both for the assert and the clear:

assert #1, clear #1
assert #2, clear #1
assert #2, clear #2
assert #3, clear #2

and so on.

What I find a little odd is the fact that there is a difference of 3-4
counts between your sequence numbers, not sure what that might be
related to.

I'd focus my attention of ntpd.  What device produces the PPS signal?
I have an NMEA+PPS GPS so I use driver #20, and not #22.

Hope this helps.

Ciao, Luca

On Fri, Oct 17, 2008 at 1:40 PM, Thorsten M. <thenktor at gmx.de> wrote:
> I guess the problem are the doubled sequence numbers? I've tried TTL and RS232 signals on pps0.
> Both give the same result, but the ktimer on pps1 doesn't have the doubled numbers:
>
> root[pps0]# modprobe ktimer
> root[pps0]# 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 1224243426.998519134, sequence: 6385 - clear  1224243426.098752871, sequence: 6381
> source 0 - assert 1224243426.998519134, sequence: 6385 - clear  1224243427.098684891, sequence: 6382
> source 0 - assert 1224243427.998518138, sequence: 6386 - clear  1224243427.098684891, sequence: 6382
> source 0 - assert 1224243427.998518138, sequence: 6386 - clear  1224243428.098754339, sequence: 6383
> source 0 - assert 1224243428.998517293, sequence: 6387 - clear  1224243428.098754339, sequence: 6383
> source 0 - assert 1224243428.998517293, sequence: 6387 - clear  1224243429.098684606, sequence: 6384