Re: MCC QUAD04

From: John Conner <conner_at_empiredi.com> · Date: Fri, 17 Oct 2003 08:09:38 -0600

Hello Vladimir,

I was able to get the MCC QUAD04 board running (both isa and pci).
But I did not move it to a comedi interface. I have a small driver
that uses /proc files to access the counters. I only needed to grab
the accumulated count when a message came in. Timing was not really
important. It actually was based on a driver from Hollabaugh's
"Embedded Linux" book.

The problems we had with the card were due to confusion in reading
the data sheet for the encoder chips. It was not a problem with the
board.

I'll tar the code up and send it to the comedi list. Maybe some one
will find it useful. Or, convert it to comedi.

John Conner

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hi John,
> 
> This is a reply to a message to the COMEDI list from March.
> 
> I'm looking for a quadrature decoder card to use with Linux, using the 
> COMEDI API if possible. The PCI-QUAD4 card from MCC suits well my 
> application, I just read your old posting where you mention a serious 
> problem. Could you resolve that problem or shall I better forget about 
> this card?
> 
> John Conner wrote on Thu, 27 Mar 2003 13:29:00 -0700
>  > I'm still seeing problems with the Quadrature Encoder board from
>  > Measrurement Computing. Both the PCI and the ISA versions act about
>  > the same. The problem is that we do not get real numbers from the
>  > counter via the output latch.
>  >
>  > We've tried a number of different ways of programming the board and
>  > all produce more or less the same answere.  We even took a very simple
>  > old dos demo from Computer boards and adjusted it to fit Linux. It
>  > doesn't work either. Watching the signals on a scope showed nothing
>  > unexpected. Timing looks Ok.
>  >
>  > Has any one got some working code for the ISA version? I heard from
>  > one person in the UK that had the problme with the PCI version and gave
>  > up.
>  >
>  > John Conner
> 
> Regards,
> 
> Vladimir
> - --
> Vladimir Dzhuvinov <vd_at_valan.net>
> PGP key CCE8 3B7C 7907 E537 A9F0  48CB 4D5A D569 AC9A 5C6C
> 
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