I am afraid I simply do not believe this. NMEA is lucky to get a ms not a
usec. The offset on the NMEA should be a lot bigger than .001
The NMEA driver includes built-in PPS support.
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Folkert van Heusden wrote:
I would like to compare 2 NTP implementations. What would be the best
way?
The biggest problem is finding out the time on the machines without
using NTP. One approach is to use a simulator, but that assumes that
the simulator correctly represents clock
Unruh wrote:
He was refering solely to the NMEA signal not the PPS. Some GPS receovers
have no pps.
In general those are not suited to accurate time transfer, and ones with
PPS cost a lot less than the the commodity car navigation devices,
because they don't have loads of map data (the
Hmmm it seems the problem is somewhat different:
- pc 1 has fine reception
- pc 2, both with on-board and external (= pci board with serial ports)
doesn't seem to receive even one single bit
I tested it by configuring a dcf-77 receiver in ntp on pc-1 (hbg is
dcf-77 protocol) and the same on
David L. Mills wrote:
It's easy to make your own Allan characteristic. Just let the computer
clock free-run for a couple of weeks and record the offset relative to a
known and stable standard, preferable at the smallest poll interval you
can. The PPS from a GPS receiver is an ideal source,
David L. Mills wrote:
Danny,
Unless the computer clock intrinsic frequency error is huge, the only
time the 500-PPM kicks in is with a 100-ms step transient and poll
interval 16 s. The loop still works if it hits the stops; it just can't
drive the offset to zero.
Dave
Yes, I found
On Jan 26, 8:05 pm, [EMAIL PROTECTED] (Folkert van Heusden)
wrote:
Hi,
I would like to compare 2 NTP implementations. What would be the best
way?
I was thinking of configuring 7 upstream servers on these 2 physical
servers and then on a third pc (which is also synced against these 7)
check
On Jan 26, 7:05 pm, [EMAIL PROTECTED] (Folkert van Heusden)
wrote:
Hi,
I would like to compare 2 NTP implementations. What would be the best
way?
I was thinking of configuring 7 upstream servers on these 2 physical
servers and then on a third pc (which is also synced against these 7)
check
[EMAIL PROTECTED] (Danny Mayer) writes:
Unruh wrote:
[EMAIL PROTECTED] (Danny Mayer) writes:
Unruh wrote:
Brian Utterback [EMAIL PROTECTED] writes:
Unruh wrote:
David L. Mills [EMAIL PROTECTED] writes:
You might not have noticed a couple of crucial issues in the clock
filter code.
I
Danny,
True; there is an old RFC or IEN that reports the results with varying
numbers of clock filter stages, from which the number eight was the
best. Keep in mind these experiments were long ago and with, as I
remember, ARPAnet sources. The choice might be different today, but
probably
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