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

unruh unruh at invalid.ca
Mon Sep 9 21:54:24 UTC 2013

On 2013-09-09, W. eWatson <wolftracks at invalid.com> wrote:
> On 9/8/2013 12:02 PM, unruh wrote:
>> On 2013-09-08, W. eWatson <wolftracks at invalid.com> wrote:
>>> On 9/7/2013 9:16 PM, David Taylor wrote:
>>>> On 07/09/2013 22:38, W. eWatson wrote:
>>>>> I'm told that Dimension 4 is an accurate time keeper.
>>>>> <http://www.thinkman.com/dimension4/> I downloaded it and installed it.
>>>>> It's freeware, but would appreciate a $10 donation. Oddly it comes w/o
>>>>> any description to use it. Am I missing something? I'm running it on my
>>>>> XP machine. Nothing is said about an OS.
>>>>> Out of curiosity I installed it on this Win7 PC. It acts like my XP
>>>>> install. That is, it has no useful help, what to do is not obvious.
>>>> There are instructions for installing NTP here:
>>>>     http://www.satsignal.eu/ntp/setup.html
>>> That's a daunting install process. See my comments about Meinberg below.
>>>> Why would you want to install NTP rather than Dimension 4, or the
>>>> Windows own time service?  See:
>>>>     http://www.satsignal.eu/ntp/setup.html#why
>>> My XP machine quickly loses accuracy. BTW, it needs to be pretty
>>> accurate, since I have a science application that runs on it 7/24. The
>>> XP is on a LAN of three PCs. Two are on Win7 in my den. The XP PC is in
>>> a building 120' from where I am now. The XP PC Data from the app is
>>> uploaded every day to a distant location, and saved in a DB. 1,000 miles
>>> from me here in N. Calif.
>> If time is important, Windows is probably not the best operating system
>> to use.
>>> I tried Meinberg for quite some time, but it flops fairly often. As I
>> flops? What are the symptoms? Also, if time is important why not invest
>> in a GPS (35 dolalrs or so) with PPS.
> 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.

It-- which noun does that "it" point to? 
Sure, you can have gps provide access via a usb port. The Sure GPS even
has a usb port on board that you can directly connect to. It is not
great timekeeping but you can probably get it to within .1 sec or so. 
The main problem is that you cannot use the PPS via a usb connection, so
you have to rely on the timing from the nmea sentences. Run the usb port
as fast as possible (high baud rate), and after some observation with
the machine connected to the internet as well, determine what the usb
data time offset is and subtract it out using the time2 option to the

>>> recall, my Meinberg software was not nearly as involved as shown in the
>>> link above.  Given the XP is outside, I don't often go out there to
>>> check the time against an atomic clock. Consequently the data becomes
>>> erroneous.
>> Since the computer is obviously linked to the net, it is not necessary
>> to go out there to check the time. You could do it against one of your
>> local machines or whatever via the net.
>> What time accuracy do you need?
> 0.1 seconds.

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