I've got a Huanyang VFD & 2.2Kw spindle - controlled via RS485 in Linuxcnc using hy_vfd. Twice in the recent hot weather the VFD has displayed the E.O.H.n error - which is overheating of the VFD. This shut down the spindle but the machine carried on with the cutting move which would have been damaging if I hadn't been there to pause the program.

Obviously I need to improve ventilation/cooling for the VFD but I also want to make sure that any VFD error will stop the machine cutting.
How do others handle errors from the VFD?

  • I could explore whether the RS485 connection picks up on errors and stop the machine via Linuxcnc,
  • I also have a Mesa 5i25/7i76 card which could read an error signal via the VFD mutli-outputs (FA/FB/FC?) and feed that back to Linuxcnc,
  • or I could bypass the software altogether & connect the VFD multi-output to my safety relay (Pilz PNOZ11) and force an E-stop.


To test out any of the above I would also need to make the VFD display an error condition - does anyone know how to do this?
Many thanks,
Nathan