Upgraded 6090 to AXBB-e need help with VFD

[kgoods]

I've got everything upgraded but have not connected the VFD for on-off and speed control yet.

The old configuation used a "flying eagle" BitSensor USB controller.

I've included a picture of the BitSensor card and the control bus of the VFD.

The way it was set up originally:
VFD --> Bitsensor card
10v --> 10v as far as I can tell this is 10 volts from the VFD to the 10v input on the bob (BitSensor)
AVI --> AVI this I assume is the variable 0-10v control signal
COM --> ACM this is the common gnd - on the bob the ACM was jumpered to the DCM (analog common to digital common)
FWD --> Out2 This is the control signal to start the spindle - as far as I can tell this is a 24v line.

Here's my issue and question.
Issue1: In order to connect it the way it was I would have to common the 5v gnd (the 5v is the common to the 0-10v AO1 pin) to the 24v gnd on the AXXB-e thus breaking isolation. I don't quite understand isolation so while I believe this would work, not sure if it's a good idea. Help?
Issue2: I guess I could wire up a relay for the spindle start but it seems like I would need another 24v supply to keep the isolation. However, if I go with the relay I'm thinking maybe the 12v pin on the far right of the VFD control bus may work for the relay side of the circuit saving me from having to get another supply.

Question: Which would be better and why? If the relay is the way to go does it seem plausable that the 12v at the far right end of the VDF control bus is meant to be the power to all the digital pins? (All the pins except the AVI pin) And... if that's the case why was the FWD pin wired for 24v to begin with? I'm l a little confused here...

Thanks for any help you can give, I've exhausted every resource I have and have spent days searching without any clarity.

Ken

PS I've also crosposted this to the CNCforums hoping for an answer from someone. Hoping someone here has already been down this road.

[kgoods]

For anyone else that runs up against this....

What I did and seems to work real well is... I figured out that all the VFD needs is for the FWD to connect to the COM for the spindle to turn on (as long as there's some voltage between AVI and COM). So I used a relay and connected the black and white wires to it. Then I took the yellow wire that was connected to the +10V on the VFD and connected it to the COM (along with the black wire). Then I ran the red wire marked AVI on the VFD to the AO1 ouput on the AXBB-e and the yellow wire from the COM on the VFD to the -5V on the AXBB-e.

So it's wired like this
VFD --> AXBB-e
AVI --> AO1 (Analog In/Out)
COM --> -5V (Power Out)
COM --> One terminal of the normally open relay
Forward --> The other side of the normally open relay

The relay is powered by the 24v power supply and I ran a control signal wire to O2 on the AXBB-e (Port 1 Isolated outputs)

I still have to start the spindle using the run button once to get it working (just as with Mach3 and the old control board) but after that I have complete control of On/Off and spindle speed both frrom Gcode as well as the pendant and the UCCNC screen.

If you're considering an upgrade I can recommend the one I just got done with. Total cost was ~$500 but it's like a new machine. No surprises, runs quiet and smooth, and the speed is about three times what I was getting before the upgrade with NO SKIPPED STEPS!

I'll be documenting eveything and putting some pictures and videos up as soon as I get some time to do so. Hopefully by months end. I'll post back here with a link in case anyone is interested.

Again, I'd like to thank all the people who post here and share their knowlege. Without you guys I would have never even got this thing working at all!

Here's some pictures of the finished upgrade (except for the tool probe I'm getting ready to install).

[kgoods]

I almost forgot.... even though the markings on the board said to remove the jumper for 10Volts on the VFD control output, I had to leave it on to get the full speed range (0-10v). Not complaining, just glad it works so well and giving a heads up YMMV...