Re: emc success

Hi Jon, i have a sugestion for cleaning up the signals did you try
using a schmidt trigger to buffer the parallel port. Also you can
try putting the schmidt trigger at the paralell port as a transmitter
and have another one located at the input to your circuit. Make sure
the schmidt triggers have bypass caps at least .1uf and also 1uf to 5
uf tantalum caps if located a long ways from power supply. If you
are running long lead lenghts use ribbon cable with every other line
a ground. only connect 1 of these ground wires to your circuit the
others should only be connected on one end.

would not hurt to check for ground loops also.

Wally K.

--- In CAD_CAM_EDM_DRO@egroups.com, Jon Elson <jmelson@a...> wrote:
>
>
> dave engvall wrote:
>
> > I do get some kind of error message about missing xemc.txt.
> > Doing a locate on the file doesn't yield any results.
> >
> > BTW: now that simulation is going I'm in a position to use real
boards.
> > How are they coming and can you estimate a possible delivery date?
>
> The motherboards came in, and I'm now testing the manufactured
> encoder and DAC boards with the motherboards. I'm finding some
> problems, mostly doe to the HORRIBLE signals coming out of the
> parallel port. I had to hack the most critical one through some
inverters
> on the motherboard to clean it up. I also had to put a capacitor
on the
> reset line to prevent false resets.
>
> Hopefully I can find the last gremlins in this shortly. The guy who
> was working on the driver software has not responded in a while,
> we may have to find somebody else to help.
>
> Jon