[ntp:questions] Trying to use Dimension 4 time keeper

W. eWatson wolftracks at invalid.com
Wed Sep 11 17:22:19 UTC 2013

On 9/9/2013 9:59 PM, David Taylor wrote:
> 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:
>    http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html#GPS-devices
> 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):
>    http://www.satsignal.eu/ntp/x86/index.html
> 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
> talking about:
>    http://www.satsignal.eu/ntp/RaspberryPi-2-with-Adafruit-GPS.jpg
> A credit-card sized box.
Not sure what you mean by "Copy the current development". Why not 
uninstall the present version, and start with a newer one?

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