Set up the spindle and ran it manually with no problem. Changed PD001 & PD002 to 1, set jumper to VI, then tried to start spindle from CM with no luck. Sent /M3S1200 thru MDI, got ~2.5V at the VFD ACM & VI terminals, but still no spindle. Tried different M3 values from 1000 to 24000 with no luck, even though VI/ACM voltage scaled proportionally.
The good news is the Shapeoko side of things is working fine if you get varying voltage at VI/ACM.
If the spindle works in manual mode, either it’s a parameter issue or the VI input is dead (very unlikely).
For the parameters, I’m afraid there are only two equally painful ways to double-check: make a note of each value individually by scrolling through them on the VFD, or reset VFD to factory settings and change the values again…
There have been a couple of cases where the latter fixed the problem, it’s easy enough to overlook one parameters while troubleshooting.
It does, the “PWM” is the “positive” signal, referenced against the controller’s GND (which is the “negative” signal in this instance). If you have the controller’s GND connected to the VFD’s ACM input, and the controller’s PWM connected to the VFD’s VI input, then you should read positive voltages at the VFD between ACM (ground) and VI (actual input), between 0 and 5V, when activating the spindle with an M3 command
Yes, with the proper setup of the VFD parameters that is what it does, it picks up the voltage on the VI input that is between 0V and 5V (depending on the RPM value used in the latest M3 command), and translates that into spinning at a given RPM (from 0 to 24000 RPM, typically)
Maybe post a couple of close-up pictures of your VFD setup, along with a dump of all your current VFD parameters ?