Hi,
Apologies if this should be obvious. I've tried searching but couldn't find what I was looking for.
I have a Fuji Frenic Mini VFD that I use to drive a spindle on my CNC router. During normal operation, I control the speed of the spindle using the PWM circuit on a Gecko G540. This includes "stopping" the spindle by running it all the way down to zero. This has all worked fine.
By default, when the VFD is powered up it's in "Stop" mode and I need to hit the green "Run" button on the front of the VFD to enable it to accept input from the PWM circuit system. In this case, "Run" means it's ready to accept PWM input, not necessarily that the spindle is spinning. The display on the VFD blinks steadily in Stop mode and is solid in Run. So my workflow is generally: Turn on the machine controller; Turn on Mach; Energize the VFD; Hit "Run" on the VFD; Start making parts. Sometimes, however, I forget to hit "Run" on the VFD and end up damaging work or breaking bits because the spindle doesn't start spinning before the tool hits the work. It's annoying.
The VFD has digital inputs for "FWD" and "REV" which, when a logic signal is applied, appear to be equivalent to pressing "Run" on the panel. I'd like to set things up so that the when the charge pump is active to the G540, the FWD terminal on the VFD goes high. Theoretically the VFD will then always be ready to accept input from a properly functioning Mach3.
First off: Is this a bad idea? It's entirely possible that I'm missing something and that I'd be shooting myself in the foot by doing this, or if there's a better / more industry standard way of accomplishing my goal. Please do tell.
Second: I'm not sure how to set up Mach so that a G540 pin is always high when the charge pump is functioning properly. Assuming the answer to the above is not "you're nuts", how do I do this?
Finally: Assuming it makes sense to use an output pin to activate the FWD pin on the VFD, is there any reason I would need to run that through a relay, or can I just connect the output from the G540 directly to the logic input on the VFD?
Thanks!
-Ben