Re: analog output

From: Calin A. Culianu <calin_at_ajvar.org> · Date: Wed, 2 Oct 2002 17:10:49 -0400 (EDT)

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
>
>
>
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