Quote Originally Posted by Al_The_Man View Post
As typical with Chinese origin equipment, it is extremely sparse on details.
Your VFD appears to have a 12v fed PLC for the functions, with Opto's that require sink to GND.
But the Boards shows virtually nothing in the way of details on any outputs that it may have.
If for example it had a opto output or transistor sink to GND it would be simple to interface it.
Don't we all wish it could work like this, the VFD Drive being used is the worst drive ever made / sold for anyone to use, then coupled to a Grbl Board it's not easy but can work with careful integration.