Greetings CNC fiends!
I originally posted this over on Geckodrive's forum but methinks it'll be answered more quickly here...
I acquired a G540 to replace the stepper controller in my desktop CNC mill (a Zenbot 1216, which at the time was only available with a Mechatronics controller) and will be using a Pololu 24v23 motor controller to drive a hefty 24VDC 15A motor as my spindle spinner. The Pololu board accepts a potentiometer input - or 0-3.3VDC into the potentiometer-wiper input, which basically acts as the input terminal to one of the on-board microcontroller's ADCs - as a control option. I noticed that the G540 has a 0-10VDC VFD output for spindle control. I'd love to have the G540 tell the motor controller what to do in response to Mach3's commands, as that'd neatly automate everything in my setup.
However, I have a couple questions on implementing this that I couldn't work out from the G540 manual, and thus far a search here hasn't helped:
Does the G540 emit 0-10VDC on the VFD OUT terminal or does it simply divide the voltage presented across the VFD +10VDC and VFD GROUND terminals? If it divides the voltage given from a supposed VFD, can it divide a 3.3VDC supply as well as it can a 10VDC?
If the G540 emits 0-10VDC I can use a multiturn potentiometer as an adjustable voltage divider to feed the motor controller, and if it can take the motor controller's 3.3VDC supply and divide that directly it's a "connect three wires and you're done" endeavor. Basically I just need to know which way I need to go with it.
Thanks in advance for any help you can give!
UPDATE: It appears that the motor controller has to provide the voltage for the G540 to divide, and the upper limit the G540 accepts for VFD+ is 12VDC. So, the question is now "can the G540 work with a 3.3-volt VFD source or does it have to be a higher voltage than that?"