hy_vfd loses modbus communication on spindle ON

Hi all,

I've been trying to get my huanyang vfd/spindle combination to work with Linuxcnc (the current liveCD version, 2.7?) with mixed success.

I can open Axis, jog the machine around, home it, no problem. The Huanyang VFD panel shows a greed LED on 'Modbus Communication' a few seconds after startup. If I start the spindle using the GUI buttons, or F9, or by entering and MDI (eg M3 S2000) - the Modbus LED goes out almost immediately, and the spindle will start up and get to a couple of hundred revs before stopping. Basically on spindle ON I lose modbus comms and can't get them back without restarting.
What details of my setup does anyone need in order to be able to help...?

Sounds like an electrical interference problem. Make sure you don't have any grounding issues (ground loops...) Proper cable shielding. And you might (probably) also need an EMI filter on the AC input to the VFD.

Also check the power cables to the VFD, it looks like they are to thin so you get a voltage drop when spindle starts.