Strange behavior with VFD

[BanduraMaker]

I'm using a gecko g540 to control a hitachi WJ200 vfd. I'm using the 0-10v signal for speed and output 1 for run control. Everything was working fine but today I came down to machine some parts and unplugged a USB cable connecting the hitachi to the compute, just because i didn't think it necessaryr. When I went to run my program, the spindle didn't start up and I almost wrecked a bit.

I figured it t on accident when I started up pro drive next, hitachi's programming software to see if any settings mysteriously changed on me. When I plugged the USB cable back in, the spindle started up!

I'm thinking this must be a grounding issue because there's no control software running on the pc to run the vfd.

My connections between the gecko are

GND, 10v and signal to pins L, H and O, Output one to smart pin 1.

Any ideas as to what may be wrong?

[BanduraMaker]

C'mon - no one?

[PEU]

charge pump enabled?

[BanduraMaker]

I fixed it, just forgot to post on this thread.

Turns out that the grounds on the control voltage and the start pins are not shared on either the VFD or the Gecko. When I tied the VFD smart pin ground to the Gecko ground it started working properly.