Apart from the charge pump (which my BOB does not recognise), is there any signal that mach gives out via the BOB that would indicate it is loaded and ready for reset??

Just trying to figure out a decent safety control plan.

The charge pump doesnt really do that either, its intended purpose was to stop the parallel port toggling during windows startup affecting your motors. Although unlikely it is still possible for Mach to have crashed and the chargepump still outputting correctly, so it should not be relied on as a safety feature on its own.

As for other signals, no not really, you can of course have outputs set so when Mach E-Stops the signal will be output but how useful that would be will depend on how your hardware is configured.
Hood

Ok thanks, will have to workaround it.

On a servo system you would usually have the drives enable signals coming from Mach so that the drives would only get enabled when Mach is out of reset.
Hood

Yes the enable port is controlled by the breakout board but pC's tend to start up with the parallel port in the wrong configuration and has the plasma torch on etc until mach is running.

The torch is easy as i can wire the torch control through my safety contactor which will also disconnect the PSU for the drive boards, i think thats a safe thing to do. This will leave the BOB and pc powered up but kill the torch and motors.

Is it ok to kill the power to drive boards if they are running or is that not a good strategy??

It would all depend on the drives, some you can some you cant. For example my AC servo drives I can but often stepper and hobby grade servo drives you cant safely.
Hood