On Monday 16 April 2018 20:11:46 jeremy youngs wrote: > The 5i25 will work with my existing breakout boards if I'm > understanding correctly. And a spinx1 will get me to an analog +-10 > that I can flip flop for reversal. I'm thinking 5i25 and softdmc > should get me where I want to be. And be expandable later on . Can the > 5i25 output a 0-5 v analog, it would be simpl to make a 2 gain > follower with op amp.
No, the closest it can do is pwm or better yet, pdm, see the docs. Reversal, if you want zero speed to be zero pdm, will need a separate gpio for signalling the spinx1 or the pwm-servo amplifier to reverse. Theoretically, a 50% pwm could be use as zero speed, but requires very accurate sensing at the creep speeds, which has always bothered me so I've never explored the -5-0+5 options. Perhaps someone who does have such a setup can comment? One other item I'd point out is that the timing of an opto-isolator will totally wreck the linearity of the control. Rip it out on that pin of your BoB, or get some sainsmart BoBs. They only have the opto junk in the inputs, so you may have to bypass the 2 used for the A/B signals from the encoder if its a hi rez encoder. I use pdm mode, which works well on the spindle motor of the mill, turning it at 20 rpm when its in between gears so the gear meshing when I turn the knob is silent and effortless, with the spindle running. There, the pdm is fed to the input of one of Jon's Pico Systems pwm-servo amplifiers, which drives that 90 volt motor rated at a horse at 2200 spindle revs in OEM configuration, to around 2hp at 3000 spindle revs. My encoder is not on the spindle, but on the motor, so that 20 rpm is plenty stiff enough to move the motor. Hal takes care of the scaling so the spindle tach is accurate in either gear. I am assuming you are controlling a vfd with a spinx1? Works great on my Sheldon lathe that way. No spinx1 is needed on the mill or the mini-lathe with their PMDC motors, its all done in the pwm-servo amp. > Sorry to be an ask hole I would like to figure > this out and order tomorrow. Thanks for input Good luck, Jeremy. And keep us posted, plz. > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > 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) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
