Roger Oberholtzer wrote:
On Tue, 2012-08-28 at 14:12 +0200, Per Jessen wrote:
Roger Oberholtzer wrote:
On Tue, 2012-08-28 at 10:14 +0200, Per Jessen wrote:
NTP knows about transmission delays and all that - to be honest, I don't know how accurate it is, I have nothing to compare to. I am not concerned about milliseconds myself, but I suspect that is the level of accuracy achievable.
I have read that inexpensive receivers, like in consumer grade clocks, should be able to achieve 0.1 sec accuracy. Better receivers can do better.
I could be way off, but I don't think it is related to the receiver quality. After all, either you've got a signal or you don't. What is done with the data received is probably more important, and that's where NTP comes in.
The DCF77 wikipedia entry (correctly?) states that inexpensive receivers typically have a 10 Hz bandwidth, and thus have this limitation.
Did you leave out a 'k'? I'm sure the bandwidth is more like 10kHz, but I think that's only of important if you're using the carrier to generate a PPS. See below.
Not sure what that means. For this kind of sync, it is not the frequency of the update, but the accuracy of it when it arrives. This is a bit beyond my expertise.
The 77.5kHz longwave carrier is also highly accurate and can be used to generate a very good PPS signal.
Using a PPS is a different solution, but I have also seen people having trouble with USB and PPS sources.
By 'Trouble' you mean it does not work. USB cannot propagate the PPS signal with the same accuracy as the serial port.
Yup. -- Per Jessen, Zürich (24.6°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org