I have a rather odd problem running a spindle via a Huanyang VFD and a USB - RS485 com-port. I'm using Mach3 with the modbus plugin.

Everything works fine if I load G-Code and run it. The spindle turns on when it should and runs at the correct speed and in the correct direction.

If I start the spindle manually by first inputting an RPM and then pressing the screen-button it turns backward. My first thought was that I didn't make a setting somewhere but the problem is stranger. If I first start G-Code and press the stop button as soon as the spindle starts, I can then start it manually and it turns in the correct direction. If I change the speed, however, it reverts and turns backward again.

Any ideas? Thanks in advance,
DB