Re: [CAD_CAM_EDM_DRO] Re: tool changer logic- mathematical challenge

> Hey,
>
> This is an existing tool turret and optical sensor design on an
> Emco cnc lathe. I'm not building it, I'm trying to make it work with
> new controls (Mach2 software).
>
> The "C" shape is built in from the factory. It is exactly a 135
> degree opening. This creates 2 trip points for each sensor giving a
> 45 degree resolution with only 4 sensors.

Ah... This started out as a quiz about the number of degrees, etc. I thought you weren't
quite sure what the "C" thing looked like yourself.

Given that my design tells you both when you're at a tool position and whcih one you're
at, I think my design is more static and deterministic. <grin>

If you must use the factory design <laugh>, the state of the sensors don't tell you much.
Only transitions of the sensors tell you where you actually are. You're going to need 4
bits (a nibble, or a half byte) of input *plus* 4 bits of storage to remember what the last
sensor state was to make any sense of that. Any transition from one sensor on to two
or from two sensors on to one will tell you all you need to know. Combine both 4 bits
sets into a single byte and then it's just an 8 bit table driven look up. Alas, that
information is only valid for the moment of the transition.

Jeff