how do i get mach to halt for a servo fault

[fast89]

I'm sure there is an easy way to do this but my brain is not in gear. I want to somehow tie all three axis together and make mach3 halt if any servo drive faults. Is it done by using the err/res terminals?

[Torchhead]

Not quite that simple. The err/res is on the DC motor side of the buss (other side of the Step & Dir Optos) and may or may not have a common (or spike free) return. If the ground is not common it's almost instant death to the err/reset circuit (aka dead Gecko) if you tie it back to the PC e-stop pin. The Geckos being opto isolated allows you to separate the PC side from the noisy motor side, but if you tie them back together with a common ground then you defeat most of the purpose of using an opto isolation circuit in the first place.

I prefer on servo systems to have the faults "or'd" together and have them turn off motor power rather than just stop MACH. You can let the power off send an isolated signal to MACH to stop the software.

If you want to use the err pins then you need to provide a reset function (power on reset) that goes away after the reset cycle so the err pin can go low on a fault.

Our EZplug Gecko cards have all that circuitry (plus differential encoder signaling) and drop wiring to almost zero.

TOM CAUDLE
www.CandCNC.com