I have a new Huanyang VFD (model HY02D223B) connected to the spindle motor on my retrofit milling machine.
I'm trying to control the speed with the analog Voltage pin from LinuxCNC with a mesa 5i25/7i77 combo. That part, I think, is working fine. I can set the spindle speed in LinuxCNC and see between 0 and 10V on the pin.
On the VFD, I've set PD001 and PD002 for external control and moved the jumper to VI. When I turn on the spindle from linuxCNC, it immediately spins up to the freq specified in PD073 even if nothing is connected to VI. If I supply 5 or 10 volts on VI, it makes no difference. Nothing I do on VI changes the speed past the minimum freq.
The manual may have PD073 and PD072 reversed and I've tried both without a difference.
I'm sure I'm missing something obvious but it escapes me.