Turn on an output when linuxcnc starts?

I have a 28" x 120" Edelstaal lathe that I have retrofit with LinuxCNC+Mesa 7i76e+Steppers for the purpose of roughing the ends of 4"OD steel shaft down to approximately 2". Everything is working satisfactorily. I am now tidying up the controls. I would like to switch off the power to my stepper motors when I shut-down LinuxCNC. Can anyone point me to a signal that goes 'high' when the software starts and back 'low' when linuxcnc closes? I have located a couple of suggestions for amp-enable-out but I don't want the relay that will be switching this power signal to follow the emergency stop function.

Hi Joey,

1. Official you have to use the Linuxcnc Machine-on output to enable your motor drives of your lathe.

2. Power of your motor drives can be switched off by emergency brake output, this is the most drastic way, conform CE.
But in that way there is a hidden danger. If machine if powered off, with peolple accident, they can not free the victem because the machine is not going to move, because of the of the motor / spindle ratio of that machine. This is one of the reasons that OEM have to make a risk analyse to be conform CE. I have seen accident's with old press brake's without a safety. It has costed the company 100.000 dollars to compensate the victem at court.

3. So your question :

Can anyone point me to a signal that goes 'high' when the software starts and back 'low' when linuxcnc closes?

you can use 2 signals, machine enable, or emergency brake.

If you want an output to be set when LinuxCNC starts and stays on until LinuxCNC exits you could just "setp" a 7I76 output true in the hal file:

setp hm2_7i76e.0.7i76.0.0.output-15 true

This will be enabled when linuxCNC parses the hal file and disabled when you exit LinuxCNC