Re: [CAD_CAM_EDM_DRO] EMC home/limit switch quality

> Les,
>
> Not sure if this would work, but, couldn't you just wire the index pulse
> to the home input on the parallel port through a normaly open switch?
> Every revolution of the encoder will put out an index pulse but the EMC
> will not see it until the switch is closed. EMC would then read the next
> index pulse through the closed switch.
>
> Bill

Bill ,

You are quite correct.

What you described is a simple "logical and" providing the input is pulled
high or low with a resistor as required. That is what I had in mind.

One could consider that an equivalent with a normally closed
switch (about as easy) might be a little more fail safe - as a
closed switch might be more likely to open properly than an
open switch to always close properly (dirt?)

As I think about it while replying It really appears to be a non issue.
Couple of resistors at most. I think I was hung up
thinking about the reverse motion after switch actuation too
much just because I always wrote the code that way.

I'm boltin' the switches on tommorow and will use the encoder index pulse
for home with emc. No big deal. No need at all for accurate switches.

Thanks,

Les
Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.rabun.net/~leswatts/wattsfurniturewp.html