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

> Cheating huh?
> Well, you are right. It's hard to describe this in words. You
> see what I'm saying though.
>
> Again, this is an existing setup, an Emco Turn 120 lathe. I have
> no clue why they built it this way, but that's what they've done.
> I'm really hoping to get it working as is. It's a small assembly,
> that would be very difficult to add microswitches or even an encoder
> to without major rework.
>
> My problem now is how to implement the logic. With another $130
> breakout board and a $10 PCI parallel port card, I 'might' have
> enough inputs to do it. Then I need to pull out some magic VBscript
> for a tool change macro in Mach2. However, I still don't know if I
> will need 4 inputs (action when going LO and HI) or 8 inputs (4 LO
> active and 4 HI active).

Am I missing something? Seems pretty simple to me. I think.

Assuming the opeing in the "C" is about 90 degrees (maybe a skosh more
to allow for the lamp width) every 45 degrees would have a unique value
at the sensors. At any one time either one or two sensors would be
illuminated and the other 2 or 3 will not be. It's a fairly simple
table-driven matter to map that pattern to tool numbers 0-7. A PIC would
do the trick quite nicely.

Jeff