Re: second computer for DRO readout

["alex" <telecomt-at-tht.net>]

Paul,
thank you again for your comments.
Of course, it would be nice to get DRO input directly into the parallel port
of EMC machine, as a part of the loop. However I red in an archives that
EMC wont be able to handle it due to an overload. If you think its
doable, I may try to give it a shot - in spite of all my programming
limitations.
I'm not sure I will be able handle a makefile and the rest which comes with
it.I had
small experience in programming of Linux parallel port, but not under RT
Linux,
which is still a mystery.
Best regards, Alex

----- Original Message -----
From: Paul <paul.corner-at-tesco.net>
To: Multiple recipients of list <emc-at-nist.gov>
Sent: Friday, December 20, 2002 6:43 PM
Subject: Re: second computer for DRO readout


>
>
> Hi Alex
>
> In desktop computers, the ISA bus is virtually extinct - Industrial
computers
> will still use it for several more years. A quick search for Single Board
> Computers will show just how many manufacturers are still committed to
> supporting the ISA bus !
>
> If a network interface could guarantee a data packet at a pre-determined
> rate, EMC could probably be kludged to use it. But the data may take a
second
> or more to arrive depending on the network load. A better solution might
be
> to use the parallel port to communicate with your encoders as Jon has done
> with his ppmc hardware....
>
> Idle thought - A PIC chip or three using D0-D7 as address lines, returning
> data on C0-C3 *might* just work... Or, figure out how to use the parallel
> port in bi-directional mode, and use an eight bit data bus.
>
> Regards, Paul.
>
>
> On Friday 20 Dec 2002 10:28 pm, alex wrote:
> > What I don't like in an ISA card is the fact that ISA bus virtually
> > disappeared by now.
> > This network distributed architecture can help to go around of this
> > limitation.
> > I wonder how much precision will be lost for a slower update times -
> > may be it work for a hobbyist?
>