On Tuesday, February 8, 2022 3:01:38 PM EST andrew beck wrote: > Hey everyone > > I have a bit of a problem here. > > I have a vfd that only accepts 0-10 input. I can't change it due to > passwords etc. It's a frenic vfd > > When set up with a physical pot it works great. > > I have 7i92m and 7i77 cards. > I think the 7i77 has the same spindle setup the 7i76 has which I have several of, and its totally compatible, and about as linear a control as there is, so I suspect you have a wiring error as its designed to minic your pot, with all 3 wires connected to the 7i77, minus to the vfd's zero volts, plus to the 10 or 12 volt src the vfd should supply, and the third wire normally connected to the arm of the pot, connects to the 0-10 volt input on the vfd. Its totally opto isolated otherwise.
Unless Peter chimes in and corrects me of coarse. :) And yes I use a spinx1 on my big lathe, to convert a 5 volt pwm style signal to that same 0-10 volt input on the vfd. But other than the pwm pin driving it in the .hal file, the rest of it is all hard wired and I'd have to gpo trace it out now after all these years. Most vfd's can also be driven if you're handy making stuff, by that PWM signal if its boosted to a 10 volt swing. They'll filter average the PWM if its a 500 hertz or higher speed signal and swings all the way up to 10 plus volts that you can generally steal from the vfd. You in that case, may have to invert the signal in your .hal file or it may work upside down, starting at high speed and slowing as the PWM duty cycle is increased. And some vfd's will need a rev wired up in in addition to the fwd. Often the menu of the vfd will lt you fix that. And they come, out of the box, horribly miss- configured, IMNSHO, with suitable re-programming, my Sheldon can reverse spindle direction at 100 revs in .24 turns, with a 40+ lb 8" 4 jaw mounted. Obviously I have clamps on the rear of my backing plates that prevent the unscrewing of my chucks. > I can't seem to get the 7i77 analog output working well. I changed > lots of settings and I think there is nothing for it. But I need a > 7i76 style pot output that is isolated. Peter: isn't the 7i77 identical to the 7i76 for that? All I know is that the 7i77 is for servo's, while the 7i76 is for stepper systems. And with one exception, I'm all stepperes or stepper/servo's.> > Does anyone know how to set up the spinx1 cards I have a spare here. > What card Do I connect it up to? Any thing you can route a PWM signal to. I can go trace what I have wrapped around a spinx1, but it will take a few hours, and I have furnace people under foot tomorrow, the heat exchanger needs replaced. So it could be Thursday by the time I make it readable. > Regards > Andrew > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > . Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
