Anyone use digital signals to connect 7i96 to a VFD?

Using a stepgen and a 5-24v level converter ought to work. You can pick up an 80khz for under $20. I think it would be a pretty cool project to tie it all together.

You could use a level translator from a stepgen output to run this
A simple small signal MOSFET (2N7000)  would do but if you
wanted isolation a logic opto-isolator would work (say a TLP104)

Hey everyone,

I love how you all just run with my questions. Thanks everyone.

I'm sorry if the topic seems crazy or frivolous, but with lock down, broken bones, pain meds, and "life getting in the way" of CNC progress... these are the things I like to think about.

What if I could use a digital signal? How would I do that? Would there be any tangible benefit? Has anyone done it and why?

Or maybe I'm just suffering from medication-enhanced cabin fever with the household pets using me as a mecca for body warmth.

Like I said, I'm not averse to analogue control, but I always like to consider alternatives.

Hope you're all well, and thanks for the interesting discussion. If anyone does it, I'd love to read about it.

Harmo.
 

Sorry if that's not what you asked for, but since your vfd has the rs485 port you can control everything with a simple usb-rs485 key. at least I do that.
Mauro

harmo wrote:

What if I could use a digital signal? How would I do that? Would there be any tangible benefit? Has anyone done it and why? 

My Nakanishi spindle controller can use digital signals. It has an input for speed up/down and another input to count the speed. spindle starts at 1000rpm and every pulse is 1000rpm, so spindle up +5, +20, on the counter. I dont yet know how to implement it yet, and i want to use it because the analog spindle speed input gets interference when I connect to the analog spindle load/speed/current outputs causing the speed to change to lower than commanded

I just set up an optidrive e3 they are nice well made vfds for sure. I don’t think you’re supposed to use external power. I think you could connect your 7i96 output pins to the 4 digital in and be able to start/stop  increase and decrease speed and reverse rotation,, for each digital in there’s either on or off 0 or 1 connect terminal 1 to one side of the ssr and di1 to the other and the same for the others.then find the gui pins that match those functions if your lucky you’ll be able to just link your relays to signals if not you’ll need to implement some Hal logic and2 or2s or find some other pin you can use it remembers your last setting so the next time you enable DI1 it goes right back to the last speed setting. Shielded twisted pairs it’s pretty electrically noisey that close to a VFD if it’s not bonded really well in reference to  ground plane of the machine.