Re: Need to implement a calendar clock with millisecond resolution, please help.
- From: David Thompson <dave.thompson2@xxxxxxxxxxx>
- Date: Sun, 09 Sep 2007 22:32:40 GMT
On Sun, 26 Aug 2007 03:07:23 -0700, Hunter <Igal.Hunter@xxxxxxxxx>
wrote:
Oh... API... Whatever that means :(
http://en.wikipedia.org/wiki/API and in this case particularly
http://en.wikipedia.org/wiki/Windows_API
As for precision, do you know how much it can "drift"?s/precision/accuracy/; see PP (previous post)
I mean, what I need is to synchronize between to programs, each
acquiring it's data from a different source (And the data rate is
about 1kHz), and saving it into the file. The programs not necessarily
start at the same time, but they do run simultaneously most of the
time. So I thought of "time stamping" the data in files.
Programs on the same machine, or different machines?
On the same machine, if that machine can be a multiprocessor -- and
any machine you bought recently in the consumer market likely was --
make sure you use a call which gets time from a 'global' or 'shared'
clock, not a per-CPU counter, since those may not be or stay in sync.
I'm confident Windows does provide such a capability, but I'm not sure
if (or when) it's the default, and if not how you get it, and since
it's implementation-specific (to Windows) it's offtopic here.
comp.programmer.ms-windows.win32 is rumored to be good.
On different machines, if you want to keep clocks in sync to the
millisecond level, you need something specialized for the purpose.
There may be some Windows-specific capability, though I haven't heard
of one; the win32 group would probably know. There is an Internet
standard (in both the de-jure and de-facto sense) for this called NTP
(Network Time Protocol), but last I looked they weren't getting very
good precision on Windows. You could try comp.protocols.time.ntp ,
and in particular www.meinberg.de reportedly supports (free) a build
and configuration for Windows from the generic/portable NTP source.
(The company's business is selling precision clock _hardware_, and
they provide this support for NTP free presumably in the hope that
lots more NTP users = somewhat more clock buyers.)
- formerly david.thompson1 || achar(64) || worldnet.att.net
.
- Prev by Date: Re: HeathField Strange Ideas!
- Next by Date: Re: initializing an int variable with all F's
- Previous by thread: Re: Function prototypes
- Next by thread: Byte parity question...
- Index(es):
Relevant Pages
|
