[LinuxPPS] 1PPS Atom Ref Clock Not being Polled?

[William S. Brasher]

On Thu, 23 Jul 2009, Hal V. Engel wrote:

> 
> This looks better but I see a new difference from what I see on my machine in 
> the above output.  On my machine the assert and clear events either have the 
> same sequence number or are at most have a difference of 1.  Yours are 
> different by 8 in the above example.  I don't know if this is significant but 
> as a guess it appears that this might indicate that the OS is not catching all 
> of the assert events on your machine.  If that is the case then the difference 
> in the assert and clear sequence should increase as you let testpps run 
> longer. 
> 
> 


I have access to several Garmin models, including the LVC-18 puck, and the 
pulse width can be adjusted in 20ms increments from 20ms to 180ms 
according to the tech specs. The default pulse width is 100ms.

The pulse width is currently set to 100ms on the GPS units attached to the 
following machines.

The ppstest output on machines currently running a 2.6 kernel is:

64 bit 1.6 Ghz Via Nano:
source 0 - assert 1248380403.000003807, sequence: 84417 - clear  1248380402.040002013, sequence: 84416
source 0 - assert 1248380403.000003807, sequence: 84417 - clear  1248380403.040002216, sequence: 84417
source 0 - assert 1248380404.000002950, sequence: 84418 - clear  1248380403.040002216, sequence: 84417
source 0 - assert 1248380404.000002950, sequence: 84418 - clear  1248380404.040001666, sequence: 84418

32 bit 1 Ghz Via C7:
source 0 - assert 1248380781.000000007, sequence: 85227 - clear  1248380780.100001150, sequence: 85226
source 0 - assert 1248380781.000000007, sequence: 85227 - clear  1248380781.100001423, sequence: 85227
source 0 - assert 1248380782.000000269, sequence: 85228 - clear  1248380781.100001423, sequence: 85227
source 0 - assert 1248380782.000000269, sequence: 85228 - clear  1248380782.100001707, sequence: 85228

32 bit 533 Mhz Via C3:
source 0 - assert 1248380583.999998896, sequence: 84567 - clear  1248380583.099998510, sequence: 84566
source 0 - assert 1248380583.999998896, sequence: 84567 - clear  1248380584.099998623, sequence: 84567
source 0 - assert 1248380584.999998729, sequence: 84568 - clear  1248380584.099998623, sequence: 84567
source 0 - assert 1248380584.999998729, sequence: 84568 - clear  1248380585.099998456, sequence: 84568