[time-nuts] Cheap jitter measurements

[Dan Kemppainen]

Hi,

Yes, but isn't generating pulses OUT of a PC with low latency/jitter one 
of the difficult issues?

If we (somebody smarter than me...) flip this around and modify a copy 
NTP to grab the QueryPerformanceCounter value when it gets a PPS pulse 
and log that count, don't we now have a way to compare the high 
resolution uncorrected counter to NTP and the external PPS?

Agreed, not trivial. But maybe fun anyway!

Dan


On 4/10/2018 11:03 AM, time-nuts-request at febo.com wrote:
> NTP already looks at incoming pulses and reports what it thinks is going on with them. The desire here
> is to get a pulse*out*  of the device. Then you can toss it into a conventional set of gear. From the data
> you can independently evaluate what’s going on.
> 
> So more or less:
> 
> 1) Generate pulse
> 2) Work out when the pulse went out
> 3) Compare that to what NTP thinks is going on
> 4) Generate a message to describe the delta in time
> 
> No, not trivial ….
> 
> Bob
> 
>