Karl Townsend wrote:

"Ignoramus31989" wrote in message
...
On a second thoughts, I was reading about PPMC on the linuxcnc
website. It would seem that PPMC includes this functionality already:
there is a relay on it that is switched off when estop is activated.

What this means is that I can wire the motive power contactor through
that relay in ppmc and it will do what I want: when estop is
activated, the motive power contactor drops out.

i

You got a pretty good plan there iggy. I'd suggest you also have a machine
stop button. This stops motion and spindle through software (servo inhibit
and VFD brake etc.). This is the normal everyday stop button. I also like a
spindle stop button. Buttons are cheap. this assumes inputs aren't a
limiting issue in EMC. I know Mach 3 really limits you on inputs for this
sort of stuff.

karl

Correction, Mach3 does not limit you on inputs for this sort of stuff.
Many implementations of Mach3 operate with few inputs, but that is not a
limitation of the program. There are a number of different ways to get
plenty of inputs to Mach3, ranging from using multiple LPT ports, to USB
connected motion engines, to USB or serial connected I/O boards, to PCI
based I/O boards. Pretty much just as flexible as EMC/EMC2, and in
either case you need to add hardware to get the inputs to the PC.