On 2 February 2017 at 01:19, Dan Bloomquist <z...@lakeweb.net> wrote: > So I don't see > the tachs being connected to the 7i77, it doesn't have analog inputs, > ADC, or there is another way? From your last paragraph, I can just go > glass into the 7i77 and it will deal with it? I've read that just glass > in is iffy, but I just don't know.
The 7i77 doesn't need the tachs if they connect to the drives as originally set up. You have two cascaded control loops. There is an all-analogue control loop with the drives and the tachs in the velocity realm, and then the 7i77 runs a position loop. It compares actal position with desired position and outputs a velocity command to the analogue velocity loop (and in the velocity loop the difference between commanded and actual velocity becomes a motor current). -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1916 ------------------------------------------------------------------------------ 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
