> > Have you actually tried to feed a software PWM into the analogue input? > They are usually filtered well enough to do that by filtering to the > average of a fast PWM. I have a huan yang clone on my 6040 I did that > with for a couple months before I found we had an rs485 driver that > worked even better. You may need to buffer that 5volt p-p signal in a > transistor to bring the swing up to the 10 volts the vfd needs, but the > vfd also can supply 12 volts to do that with. You'll need two transistors > to keep from inverting the speed range, look up a long tailed invertor on > google. Better yet, a ttl input cmos output AND gate, will give you a > full rail to rail signal. Check the docs from the vfd, you may need to do > the same with the dir signal. Generally both the run and dir signals are > energized by pulling that input down to ground from its open circuit of > 10 volts. Or use a Mesa SpinX1. I'm using that on my sheldon to do the > reversal when rigid tapping in 1/4 turn at 100 spindle rpms. Response > speed if the vfd is tuned correctly, is not a problem. Generally, they > are not tuned "Out Of The Box".
Hi Gene, I hope you're doing great Well, I can try that but I recall we did a simple low pass filter years ago for a colleague's machine and it worked really well. I think I'll try that one and see how it goes. I didn't order the SpinX1 when I purchased the boards because I was sure I was going to use pulse input. I'll flash the 7i95 tomorrow and see how it goes. I wish you the best Gene and thanks as always for sharing your knowledge :) El vie, 1 abr 2022 a las 14:03, gene heskett (<ghesk...@shentel.net>) escribió: > On Friday, 1 April 2022 09:51:50 EDT Leonardo Marsaglia wrote: > > Hi guys, I hope you're all doing well > > > > Quick question to define a little issue I have. I purchased a VFD that > > I wrongly thought had a pulse train input for speed reference. Turns > > out that feature it's optional so I need an additional card to have > > it. By the way this Simphoenix E280/E580 VFD can reach more than 800 > > hz so it's a good candidate for high speed spindles (which is the main > > reason why I purchased it). > > > > So my question is: Is it that difficult to modify the firmware on the > > 7i95 to add at least 1 PWM generator so I can easily convert that to > > analog voltage? Because if not, I need to make a frequency to voltage > > converter which is a little trickier. I prefer the PWM option of > > course. > > > > Thanks as always for your help and knowledge :) > > Have you actually tried to feed a software PWM into the analogue input? > They are usually filtered well enough to do that by filtering to the > average of a fast PWM. I have a huan yang clone on my 6040 I did that > with for a couple months before I found we had an rs485 driver that > worked even better. You may need to buffer that 5volt p-p signal in a > transistor to bring the swing up to the 10 volts the vfd needs, but the > vfd also can supply 12 volts to do that with. You'll need two transistors > to keep from inverting the speed range, look up a long tailed invertor on > google. Better yet, a ttl input cmos output AND gate, will give you a > full rail to rail signal. Check the docs from the vfd, you may need to do > the same with the dir signal. Generally both the run and dir signals are > energized by pulling that input down to ground from its open circuit of > 10 volts. Or use a Mesa SpinX1. I'm using that on my sheldon to do the > reversal when rigid tapping in 1/4 turn at 100 spindle rpms. Response > speed if the vfd is tuned correctly, is not a problem. Generally, they > are not tuned "Out Of The Box". > > Take care and stay well Leonardo. > > 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 > > > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
