Good Job Dave, If you ever get interested I have been working with a UCCNC unit(UC300) it has a LOT of native I/O(5 ports full plus an analog port) including analog in and out. It is already is a good Plasma controller . I hope that it gets even better in the near future (;-)

Cand CNC does have good basic hardware they just went WAY overboard and made a lot of it over complicated for the average user. And they went way overboard on manuals.

(;-) TP

Almost there now, I need to sort out how to trigger the probe when I am in "dry run' mode as otherwise it just crashes the Z into the plate

Currently the probe control valve circuit is only live if two parameters are met -

The user variable 1239 must be = 1 (this is controlled from g-code)
The Extract fan (output 1) is turned on (this stops the probe from triggering as the G-code is loaded into mach as it only comes on during a live run)

So I thought add another brain that triggers the output if the 'Dry-Run' LED (UserLed 2244) is lit AND the Run LED is lit but it did not work.

Is there a way to achieve what i need here easily??
Can you run two brains against one output??

This has been resolved now, the final solution is here...

http://www.machsupport.com/forum/index.php/topic,31649.80.html