On Thursday 13 April 2017 08:07:16 Eric Keller wrote: > On Thu, Apr 13, 2017 at 2:43 AM, Dave Caroline > <dave.thearchiv...@gmail.com> > > wrote: > > You could get an analogue in connected to stepgen.N.position-cmd to > > do this with any scaling needed. What is the use case? > > I have a data acquisition device that only puts out analog voltages. > I want to have it control a motor to follow a fairly small magnitude > sine wave. The actual amplitude isn't particularly important, but it > has to stay within set limits and be reasonably repeatable. I have a > fairly tight budget, and the USDigital device would have been perfect. > I think they used a A/D converter with some sort of logic chips to > generate step/dir.
If your budget is money, the siggen module is free, as is a sum2. The siggen may be able to do it all as it has lots of control pins. The sum2 can have its individual input gains set to small, even negative values in order to subtract one input from the other. The a/d converter, depending on the interface card, might have to be an external, costs money item. I've not used that input mode myself, but IIRC some of the firmware for the Mesa cards can do a 12 bit a/d if thats (0-4095) enough resolution. I do see a possible problem in "homing" the stepper though if it operates more than one turn from "zero" when in operation. > ---------------------------------------------------------------------- >-------- 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
