I have tried various settings to get G540 to output the correct PWM voltage on terminals 7&8 with no success. (The 4 stepper motors work fine).
The first time I powered ON my Chinese VFD it was programmed for local control and the spindle started at very low RPM. Turning the speed knob had no effect on the spindle speed (spindle is water cooled and I can hear the VFD powered ON the water pump). But when I switched ON the power to the G540 it went to full speed in a second and I turned it OFF with my Estop to avoid damaging the spindle.
Reading on the web, someone suggested to first check the voltage on the G540 terminals 7&8. Doing that (with the wiring to VFD disconnected) I get between 0.09 – 0.12vdc with speeds M3S6000 to M3S24000) Changing the Mach3 settings to various combinations including the pulley settings from 0-24K and other combinations, the volts remain the same.
I used the Gecko 540BVFD.XML but now it has changed because of the various new settings regarding motor outputs, output signals and motor tuning but under Spindle setup on Mach3 I left the default settings in the motor control (Use Spindle Motor Control and PWM Control are checked, PWM Base Freq. = 50, Minimum PWM = 5%)
The G540 terminal 5 is connected the VFD FOR (terminal 6 is not connected to anything)
Terminals 7, 8, 9, ARE connected to VFD ACM, VI and +10V respectively
The water pump is connected to VFD terminals FA & FB (pump works fine)
The G540 terminal 12 is connected to VFD DCM plus to earth ground plus to the PSU negative (all separate wires).
Any ideas for help?