Re: potential product

Hi Jon,
You are correct, the Xylotex three axis board is not opto-isolated.

I'm pretty sure your system would work with the requirements of the
chipset(Allegro), but a note: the logic high input is not exactly
TTL. To be detcted as a 1, the voltage needs to be at .7V * Vcc.
Typically Vcc is at 5.0V, so a logic 1 would need to be 3.5V A few
users did have some problems reaching this value with low power built-
in motherboard parallel ports. If you drive to almost 5V there
would be no problem.
The board responds to rising edge STEP signals. The DIR line must
be stable 200ns before and after the rising edge, and the STEP
signals must be valid for at least 1uS.

Jeff

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
>
>
> Alex wrote:
>
> >Jon,
> >can you make it to work with Xylotex too.
> >
> >
> I'm pretty sure it WILL work with Xylotex. I haven't
> tried it, however. But, if the Xylotex takes inputs via
> 0 - 5 V logic signals, that should work. There is some risk
> of damage to the USC or Xylotex boards if there is a heavy
> ground loop current, as I think the Xylotex does NOT have
> optoisolators on its inputs. Proper power supply to drive
> wiring should prevent this problem.
>
> Jon