Quote Originally Posted by A_Camera View Post
There is one HUGE disadvantage with using 0-10V, at least with the BoB's I have, is that if Mach3 is not fired up and the BoB is getting power then it will output 10V and random states for the digital outputs. This creates a dangerous situation since the spindle can start spinning when your hands are too near. This situation can never happen if you use Modbus.
I can't disagree, although in my case I am using a CSMIO-IP/M which is held in e-stop mode by the safety relay until it is explicitly re-enabled. I think that it stays in standby until it starts communicating with Mach3 as well - I'll have to unplug the Ethernet cable while it is running and see what happens!

As I am currently using a Huanyang VFD and given its poor support for Modbus, I'm not going down that path. Still, if it blows up one day and I have to replace it, then I might well look for something that both supports the official Modbus standard and also has a usable manual!

Good luck with this project - I shall follow it with interest.