Re: Strangeness with cb_pcidas and 1602/16 board

On Tue, 13 Aug 2002, David Schleef wrote:

> On Tue, Aug 13, 2002 at 11:04:12AM -0400, Calin A. Culianu wrote:
> >
> > You haven't replied to my last email, which is ok, I realize I rambled a
> > bit and basically agreed with you.  But how do you feel about, in
> > principle, alleviating some of the voodoo behind guessing the wait times
> > in the application by possibly building infrastructure in comedi that
> > allows a user to query the wait time for his multiplexer?
>
> I can add an element (or elements) to the subdevice info structure --
> that's not a problem.  However, it is unclear how to precisely
> define one or several settling time parameters, since every manufacturer
> does this differently.  The best I can come up with is "worst case
> settling time for full scale step to +/- 1 LSB while changing between
> channels with the same gain".  I can find a numer of reasons why this
> is inadequate, but I suppose it's better than nothing.

Yeah if there's no method to the madness that can cover every board and
its multiplexer quirks, then I guess the best we can do is worst case
settling time...

I don't mean to trouble you Dave.. and by no means do I want to rock the
boat.  I just sort of thought it would be cool if the drivers alleviated
some of the pressure from the application when it comes to board-specific
information.

Oh well.. I really am beginning to agree with you about this being a can
of worms.. and really who's going to do the legwork of adding the
worst-case information for each board into comedi?  I can do it, if you
decide to add that field to the subdevice info structure... :)

Cheers,

-Calin

Received on 2002-08-14Z15:05:22