Re: analog output

From: <tim.hayles_at_ni.com> · Date: Wed, 2 Oct 2002 16:52:45 -0500

NI boards with analog output have external voltage references for this
purpose. Supplying an external voltage reference of 1V will allow you to
use the entire DAC range for an output of +/- 1V.

- Tim Hayles

"Calin A. Culianu" <calin_at_ajvar.org>_at_comedi.org on 10/02/2002 04:10:49 PM

Sent by:    comedi-admin_at_comedi.org

To:    Brian Hom <bjh72_at_email.byu.edu>
cc:    <comedi_at_comedi.org>

Subject:    Re: analog output

Well, I was under the impression that many boards have different output
gain settings.  It might be the case that your particular board has a gain
settng of +/-1V.  Look at the comedi_get_n_ranges() and
comedi_get_range() functions to determine the voltage ranges for the
AO subdevice.

Since I am assuming you looked into your board's capabilities already, I
would suggest doing some signal processing.  Take your +/-10V output
signal (whatever it may be) and use a really good amp (or whatever you
call the piece of hardware that can do this) to bring the gain
back down to +/-1V.  That way, you have the best of both worlds:
fine-grained control on the DAC side, plus the exact voltages you require.

-Calin

On Wed, 2 Oct 2002, Brian Hom wrote:

> I am trying to write an application that will be able to send an analog
DC
> voltage between +/- 1V. The problem that I've encountered is that I only
> want to have an output in that range, but I want to be able to use the
> entire DAC range, instead of just the 200 numbers that would normally
fall
> in that range.  I would greatly appreciate any help.
>
> Brian Hom
> bjh72_at_email.byu.edu
>
>
>
> _______________________________________________
> comedi mailing list
> comedi_at_comedi.org
> https://cvs.comedi.org/cgi-bin/mailman/listinfo/comedi
>

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