Dear Johann,

I agree with you about time stamps not all requiring the dd/mm/yyyy. I
am only a beginner at labVIEW and working on a very simple programme
(which I still can not get right) but all I need is millisecond, second
and minute readings fixed to my waveform (a heart rate) not all the
other things. Is there not some way to get this on our data. 

Regards,
Eileen   

Eileen Mansfield
FELS / CHDL
240D Briggs Building
Open  University
Walton Hall
Milton Keynes
MK 7 6AA   

Tel: 01908 858824
Fax: 01908 858868

email: [EMAIL PROTECTED]



-----Original Message-----
From: Junginger, Johann [mailto:[EMAIL PROTECTED] 
Sent: 20 January 2004 21:52
To: '[EMAIL PROTECTED]'; Info-LabVIEW
Subject: RE: Question Refined...



I have never been thrilled with the waveform data type, although it does
make some things easier. Part of my gripe is the time-stamping: If I'm
acquiring 1.0 second of data at 10000 samples/sec, I do *not* want my
time values represented as D/M/Y H:M:S.xx. I suspect there may be ways
of customising that format, but they are never obvious when I'm coding
something. Why can't you easily force it to default to milliseconds?

If I'm doing time based calculations (such as obtain the Y reading .25
seconds after a trigger event has been detected, where trigger is on a
seperate analog channel) I find that forcing t0 to 0.0 (using a
constant) helps my numbers to come out right. 

Something else I usually do when I get tired of the conditions imposed
on me by the waveform type is to build a 2D array with X and Y as
columns (or as many Y columns as I have channels). You can easily build
your X column in a loop using the dt property of the waveform (which
seems to default to seconds). This may be the solution for your Matlab
problem (I am not
familiar with Matlab syntax or data).   

It seems that even after the hysteria of Y2K time stamps and time stamp
formats still cause people grief. I think a lot more LabVIEW
applications acquire data over a span of seconds rather than weeks or
days and I don't feel the waveform data type has been well implemented
in that respect. Those list readers who know better are invited to
correct me. :)

Johann Junginger.



-----Original Message-----
From: Thomas Gary [mailto:[EMAIL PROTECTED]
Sent: Tuesday, January 20, 2004 16:29
To: Info-LabVIEW
Subject: Question Refined...


Wireworkers,

With more investigation... I've found that my t0 variable on the Build
Waveform VI is a Time Stamp. I've never used a time stamp with my
academic Matlab code, so my next question is how do I convert a time
stamp into a Real number, namely zero.

Gary L Thomas


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