Path: news.mathworks.com!not-for-mail
From: "Davide Borelli" <davidepub@microonda.net>
Newsgroups: comp.soft-sys.matlab
Subject: Re: continuous acquisition
Date: Wed, 5 Dec 2007 11:07:40 +0000 (UTC)
Organization: Universita di Parma
Lines: 36
Message-ID: <fj60ps$qi6$1@fred.mathworks.com>
References: <fj60m2$p81$1@fred.mathworks.com>
Reply-To: "Davide Borelli" <davidepub@microonda.net>
NNTP-Posting-Host: webapp-02-blr.mathworks.com
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 8bit
X-Trace: fred.mathworks.com 1196852860 27206 172.30.248.37 (5 Dec 2007 11:07:40 GMT)
X-Complaints-To: news@mathworks.com
NNTP-Posting-Date: Wed, 5 Dec 2007 11:07:40 +0000 (UTC)
X-Newsreader: MATLAB Central Newsreader 1205384
Xref: news.mathworks.com comp.soft-sys.matlab:440912



Sorry I posted the same message 5 times, but it seemed the 
connection didn't work!
Davide B.

"Davide Borelli" <davidepub@microonda.net> wrote in 
message <fj60m2$p81$1@fred.mathworks.com>...
> Hello
> I acquire with a NI PCI-4454 board and I need to acquire 
> data with high frequency (above 20kHz) for several 
> minutes; I would also like to plot the data (at least 
one 
> per second) while acquiring them.
> Is it possible?
> At first I tried with this cicle:
> 
> for i=1:NumberOfMeasures
>     tic
>     start(ai);
>     trigger(ai);
>     data=getdata(ai);
>     MeanValue(i)=mean(data);
>     plot(MeanValue);
>     t=toc;
> end
> 
> The problem is that the toc time is about 0.3 seconds, 
> that is too much to acquire fast-changing potentials... 
> but if I use a unique acquisition I cannot make it last 
> more than few minutes, because the number of data 
acquired 
> is too big!
> Is there a solution?
> 
> Than you
> Davide B.