Re: Unipolar X Bipolar X single-ended X diferential

Ok, thanks by your reply, but the question isn't driver/board specific... I
just wanna know if I can configure some arrangement like this:

single-ended + bipolar

{} 's


2007/6/27, Ian Abbott <abbotti_at_mev.co.uk>:
>
> On 22/06/07 14:45, Paulo André Capellari wrote:
> > I'm wondering about the following: in a daq-board, the Unipolar/Bipolar
> > function determines the arrangement (single-ended / diferential) of the
> > circuit or not?  Can I do the acquisition in a configuration like this:
> > Bipolar in single-ended mode in the pcm-3718, for example??? (the board
> > isn't the problem, the configuration is....)
>
> As far as I can tell from the pcl818.c driver source, you can't choose
> the single-ended / differential arrangement programmatically.  I think
> it must be set by a jumper or something.  The driver reads the card
> status during comedi_config to determine which mode it is in.
>
> Unipolar / bipolar are just different types of voltage ranges.
>
> You can specify the analog reference and the voltage range in the
> channel list by using the CR_PACK(chan,rng,aref) macro to construct the
> channel list entry.  The analog reference would be AREF_DIFF for
> differential mode, and probably AREF_GROUND or AREF_COMMON for
> single-ended mode.  But the pcl818.c driver ignores the analog reference
> specified here.
>
> --
> -=( Ian Abbott _at_ MEV Ltd.    E-mail: <abbotti_at_mev.co.uk>        )=-
> -=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-
>



-- 
Paulo André
Ciência da Computação - Unioeste/PTI