[ntp:questions] Re: Generating a PPS output.

David J Taylor david-taylor at blueyonder.co.not-this-bit.nor-this-part.uk
Sat May 27 09:42:50 UTC 2006

Alexander Fisher wrote:
> Hello
> I have an application where I'll have 2 PCs on an ethernet LAN.  One
> of these will be fed a GPS PPS input and act as a level-1 NTP server.
> The other PC will be an NTP client.  I need to get the client PC to
> output a PPS signal.  The new PPS signal needs to match the original
> to within 1 ms.   The LAN will be 100Mb/sec or better, won't contain
> many switches and will hopefully not be highly loaded.
> Many thanks,
> Alex

It would obviously be far simpler to run a second PPS line from the 
original PPS device, it's just RS-232 levels after all.  I presume that 
this is not possible for your environment?

There was a Microsoft research paper quoted here recently showing that a 
specially configured NTP could get within (IIRC) a few tens of 
microseconds for playing audio streams.  Maybe some tips from that 


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