[ntp:questions] Setting up a NTP Time Server

Hal Murray hal-usenet at ip-64-139-1-69.sjc.megapath.net
Wed Apr 9 04:24:16 UTC 2008


>>No. All you need is refclock_nmea (127.127.20.x) for a directly
>>connected NMEA device. Assuming that you're using a Linux kernel with
>>PPS-kit or a BSD kernel (or another kernel which directly supports PPS).
>
>OK, lets assume the kernel does NOT have the PPS support. Then what?

If you setup a NMEA refclock, it runs off the text strings
on the serial port.  It works, it just doesn't keep as good
time as you normally get from PPS.

How good depends on your GPS device.  A lot of them have
a lot of jitter.

You also get jitter from the OS (and serial port hardware).
There should be a simple recipe to minimize that.  I haven't
seen one and several tries haven't produced anything that
I'd call good-enough.  (When I run out of other things to
work on...)


-- 
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