Its very simple.

First- you dont connect the VFD 0-10vdc input to the LPT port.

You connect it via separate cable to the breakout board of the machine which has to have dedicated output for spindle speed control with a trimmer to adjust voltage. if board is good, that would need a separate small 12vdc 0.2A transformer to be connected to board.

On the VFd side typically VI is +, so are you sure about that schematics? Typically on any VFD i have seen VI is + and from diagram ACM must be the common, so double check that. Read manual cause may be depends if you have changed somewhere parameter "sinking" and "sourcing" and that changes. Depending on what region is set the VFD i mean that could change and be oposite, so take care and set it for EU. Cause maybe line HZ and voltage input is also not set right.


So question is:

what breakout board you have on your machine. In breakout board manual it is clearly stated how to connect to VFD.

If the breakout board lacks 0-10VDC output for spindle, then you will need a separate small board to do that. I will tell you from where and model, if thats the case.