Quote Originally Posted by Neale View Post
I'm very interested in this, but then, I am a techy...

It's not because of the start/speed control aspect, as this is pretty straightforward if you have a BOB or motion controller with adequate analogue output. OK, linearity might not be absolutely spot-on but I doubt that for most practical purposes that matters.
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.

Quote Originally Posted by Neale View Post
However, the idea of being able to read back VFD parameters (spindle speed, etc) to display on the PC screen sounds attractive. Personally, I would not have considered this because I had no idea what a Mach3 brain was so would have never gone looking for this kind of information. I've probably missed something obvious, but I don't find the Mach3 documentation leaps out at me. Easy enough to do the basics but you seem to be somewhat on your own if you go just a little off-piste.
I agree, this is another major advantage of using Modbus, and I will cover that in my next video. I am reading parameters like Output voltage, current, torque, power, temperature, real RPM, RPM stable... and there are plenty more, but to read those and have some use for them you also need to modify Mach3 screens used, otherwise you won't be able to see those. I have just started with this, so I am no expert, but used Screen4, which can be downloaded from Mach. I find it pretty buggy, crashes fairly often, so frequent backup of the changes is really important, but it is free, so why complain? In any case, to make modifications to existing screens is pretty simple.

Quote Originally Posted by Neale View Post
For example, do a Google search for "mach3 brain" and the best result seems to be a YouTube video. Personally, I would rather have a decent manual in front of me!

But maybe I've just missed some hidden site full of Mach3 docs, so if anyone can tell me where it is... In the meantime, I shall follow this thread with interest.
Yes, I would also prefer a decent manual, but that is hardly going to happen now that Mach3 is dead. The Brains territory is even less documented than the rest. I managed to gather quite a bit of documentation spread around on the Internet about Mach3 macro programming, use and parameters, as well as about some other bits and pieces, but very little about Brains, so that is not really like skiing off-piste, more like skiing off-piste uphill. Yes, the best I could find was also Youtube video, but unfortunately not enough to help me, so I made my own. I don't know if I will write some kind of user documentation later on, because it takes quite a lot of time, but at least I will document my workflow which can be use by others to figure out what to do and how to solve their problems.