I have spent probably 100's of hours already searching reading and attempting to solve my problem.
Problem Mach3 Breakout board sends 0-10V depending on selected speed 2.5v=6000, 5v=12000, 7.5v=18000, 10v=24000 So I know the settings in Mach3 and the Breakout board is functioning as required. But the speed of the spindle does not match what mach3 is commanding and is being send through the 0-10v to the VFD.\
I have a laser Handheld tachometer with a sticker on the ER-11 Nut used to verify the speed of the spindle, and is calibrated on known speeds such as belt driven lathe, etc.
What I have;
Spindle: Huajiang EYS8043-24/1.50 Air Cooled 1.5KW Spindle (see data plate Pic)
VFD: Huajiang H100-1.5T4-1A VFD (attached first -38 pages. More can be provided upon request)
Mach3 Breakout Board - BL-USBMACH-2.22 (https://www.steppermotorcanada.ca/bl5breakoutboard.pdf)
The function codes I have in the VFD are in the attached spreadsheet.