I'm trying to use the analog spindle control on the 7i76e to control a speed controller that uses a potentiometer on a floating ground at line voltage. I'm using a KBSI-250D signal isolator to protect things and bring the signal from the 7i76e to the proper levels. I have configured the spindle output to 5v at full speed (as required by the controller).
Current wiring configuration:
Ground from an unused step/dir to TB4 pin 1
5v from same unused step/dir to TB4 pin 3
TB4 pin 2 to KBSI input +
Ground from unused step/dir to KBSI input -
Problem is, I only get 2.44v at full speed rather than the full 5v I would expect. Interestingly, measuring TB4 pin 2 and pin 3, I get 2.55v (making up the rest of the 5v I was expecting).
I'm sure I'm missing something obvious, but I sure cant see what it is.
HAL and INI files attached.
Any ideas?
Darryl
