[LinuxPPS] Offset and jitter of GPS/DCF PPS signals

[Heiko Gerstung]

Hi!

Thorsten Mühlfelder schrieb:
> Hi,
>
> Linux 2.6.28 on the DCF server
> Linux 2.6.28rc6 on the GPS server
> both with LinuxPPS patch.
>
> ntp 4.2.4p5 was built with the glibc nano patch.
>
> All running on a Slackware based distribution.
>
> Thorsten
>
> PS:
> The PCI cards:
> Meinberg GPS170PCI v1.10
> Meinberg PCI511 v1.00 (dcf)
>   

The offsets are typical for this kind of setup, I would say.

Best Regards,
  Heiko


>
> On Thu, 22 Jan 2009 16:25:41 +0100
> Heiko Gerstung <heiko.gerstung at meinberg.de> wrote:
>
>   
>> Thorsten,
>>
>> which OS?
>>
>> Regards,
>>   Heiko
>>
>>
>> Thorsten Mühlfelder schrieb:
>>     
>>> Hi everyone
>>>
>>> I just wanted to ask what you guys think about my graphs. I'm using 2 servers with Soekris AMD Elan (133MHz) boards: Number one has a Meinberg PCI DCF77 card, number two has a Meinberg PCI GPS card. Both Meinberg cards have a PPS output, too. The servers get their timecode by DCF/GPS and are synchronized by the PPS signal of their own cards.
>>>
>>> Here you can see how the ntpd on the DCF server sees the PPS signal of the DCF card:
>>> http://img-up.net/img/dcf-ppsURM2775K.png
>>>
>>> Here you can see how the ntpd on the GPS server sees the PPS signal of the GPS card:
>>> http://img-up.net/img/gps-ppsoNL9T8F4.png
>>>
>>> Do you think these values are OK?
>>> I think the DCF PPS can't get any better because of the technical specification of DCF77.
>>> But I don't know about the GPS server? Is it OK or should it be better? Also I wonder about the constant 15 us jitter value.
>>>
>>> Greetings
>>> Thorsten Mühlfelder 
>>>   
>>>