hi hope someone can help I have just installed a huanyang vfd and spindle and put the vfd plugin in the right place and mach3 is switching the spindle on and off and rising and lowering the speed but the RPM dro in mach3 is showing a different rpm to what the spindle is rotating it also has a rpm displayed even with the spindle at stop can someone point me in the right direction to what is doing this thanks

Mach3 will only display the commanded speed, and has no idea of what the actual speed may be.
If the VFD is running the spindle at the wrong speed, you probably have some settings wrong.
Can you give some examples of the differences you are seeing?

Hello
a good site where you can find a plugin for the Huanyang VFD and Mach3
I use it for years and it works very well

http://royaumedeole.fr/informatique/plugin-mach3-pour-vfdhuanyang/

thanks tulip6 I was using a different plugin but as soon as I changed to the one you suggested it is all working like it should rpm is running the same as mach3 states and the rpm goes to zero when the spindle is off