Re: stepper encoders

--- In CAD_CAM_EDM_DRO@y..., JanRwl@A... wrote:
<snip>
> inverted inputs, and I suppose some might be configured to "want"
both, but I
> can't imagine why!
>
</snip>

The reason why an encoder circuit would "want" both A and A# is
for data integrity. Lets assume that A is LOW (thus A# is HIGH).
Just sitting there everything is OK. Now a voltage spike is
introduced into the system (somehow). This could raise the A from a
voltage equating to LOW to just over the threshold where is gets
detected as a HIGH (BAD). If the A# is also included, it will also
get the spike and its voltage will raise as well. Now, rather than
just checking the voltage of the line, we compare the A and A#. If A
is greater than A# we can say the level is HIGH. If A# is greater
than A we say the level is LOW. A voltage spike introduced won't
change the way the two signals compare to one another, it will just
raise their respective voltage levels.

Jeff
www.xylotex.com