[ntp:questions] Trying to use Dimension 4 time keeper
david-taylor at blueyonder.co.uk.invalid
Tue Sep 10 04:59:20 UTC 2013
On 09/09/2013 20:57, W. eWatson wrote:
> It moves many seconds in a short time, say a day or two. How is GPS
> going to help? Does it provide access via a USB port.
You can use GPS over a serial-to-USB converter. You may also find that
your motherboard has a COM port header even though it's not brought out
to the back - that's the way to get best reults. The serial output
alone doesn't provide very good results, although if you can turn up the
baud rate high (e.g. 115,200 baud) it can reduce some of the jitter, as
might getting the GPS to send just one sentence. If (and it may be a
big ask) the serial-to-USB sends the DCD line, you can use the PPS
signal from the appropriate GPS to get significantly better performance
than using Internet servers alone.
Some GPS/PPS devices I have used are listed here:
To get the best timekeeping, I would recommend that you up#grade to the
current Meinberg port (4.2.6p5), and then copy the current development
version binaries on top of a working 4.2.6p5 installation. The binaries
can be had here (except for Windows 2000):
Be sure to backup your 4.2.6p5 installed binaries, just in case.
For 0.1s accuracy, from Brian's observations, it seems that a local
GPS/PPS receiver would be well worth the effort. You could also add a
low-cost Linux box into the mix with a built-in GPS/PPS receiver, and
sync the Windows systems from that. Here's the sort of size I am
A credit-card sized box.
More information about the questions