<P>Neville,</P>
<P>I just tried to do an SCXI strain gauge project with
DAQmx and the most recent drivers and also had horrible
experiences. I don't think the addressing of SCXI modules
and channels is right. After my customer and NI didn't
have any luck at it, I had to make an emergency plane trip
to fix the system and ended up reverting to traditional
DAQ. NI was supposed to be following up on this as of
April 27th but I haven't heard any reports on what they've
found. Sorry for not posting this earlier but...</P>
<P>DON'T USE DAQmx with SCXI!</P>
<P>--David Moore</P>
<P>P.S. We also found that strain gauge excitation worked
under DAQmx for Windows, but broke when we switched to
DAQmx for LabVIEW RT. I was able to rewrite the app as
non-RT but obviously should have ditched DAQmx at that
point.</P>
<P>> >Subject: Software bug with NI-DAQmx 7.1, 7.2
& SCXI >1125-SCXI 1313 >From: "Neville Dholoo"
<[EMAIL PROTECTED]>>Date: Fri, 7 May 2004
07:09:59 -0700 > >Hi Guys, > >Just spent 2
days isolating a very specific problem that >I had when
>using the SCXI 1125 module with the SCXI 1313 breakout
>board. > >I set up an analog input virtual
channel in old style DAQ >(7.1 and the >latest
version 7.2) and the corresponding global channel >in
DAQmx. > >The old style daq channel worked fine, but
the DAQmx >channel just read >garbage. >
>Repeated support calls (yes we signed up for the
>subscription!) didn't >produce much help from NI.
> >I finally narrowed it down to the specific
channel range >I was choosing >(+/-15V). The old
style daq allows you to specify the >individual gain
>(on the specific SCXI 1125 channel) and attenuation
>(provided by the >programmable breakout board).
>DAQmx does not. It automatically sets both these
>parameters based on >signal input range. However,
it looked like it set up >the attenuation
>correctly, but the gain setting was probably wrong.
> > >Work-around: I had to use a daq channel on
the PCI daq >card instead, >with a potential divider
to bring the signal voltage down >to +/-10V.
>Changing the code back to old-style daq was not an
>option, this late in >the game. > >Hope this
saves someone else some time. > > >Cheers, >
> >Neville Dholoo >Cellex Power Products, Inc.
>Richmond BC >Canada >
>----------------------------------------------------------------------
</P>
