On Monday 30 October 2017 15:20:35 andy pugh wrote: > On 30 October 2017 at 17:49, Gene Heskett <[email protected]> wrote: > > Which is computationally less cpu usage 1, a 6 pack of mux2's, or > > another pid with separate settings and just one mux2 to select which > > pid gets sent to the spindle servo? > > PID is not very CPU intensive, neither is mux2. I wouldn't really > worry about either. > > You can see how much CPU time each module uses in HAL. > > The "lincurve" component was intended specifically for this type of > situation, which is why it has outputs of the r/w style that can be > connected directly to the pre-2014 PID gain pins (which for no good > reason were bidirectional) > > But in this case mux2 seems more appropriate if it is a simple switch > between states. > Between pid.sh.output and pid.sl.output. When I get everything else working again. Probably not yet tonight as I had to come and do something about an empty skillet for dinner. > However, I suspect that your problem is that you are trying to use P > on a controller that only really needs FF0 and I.
A dc powered spindle is a velocity servo I think, so I been trying to follow John Thorntons wiki article from 2012 where he describes tuning a axis servo in the velocity mode. Is this the wrong approach for a spindle that needs to have quite stiff control? And I just found his other description of spindle tuning, where its all FF0 and Igain. That one however doesn't describe the hardware setup at all, nor does it have any halscope pictures. I suspect that the spindle John was calibrating was being driven by a vfd, which is inherently a pretty stiff drive. But when I get it back to where I can run it (I'm in the middle of moving the spindle power control sequencer from the 5i25 P3 to the same on P2, which feeds a different bob in a different box. And reconnecting it to where I can use an A axis with those pins, and while I am up on the ladder, I'll get the individual boxes bolted together to prevent another short that blew a chain of 5i25's). I really ought to build another, even bigger box, at least another 3" deeper, and 4 or 5" taller so the A driver could fit inside it. Unforch that would take another half a sheet of 1/8" alu plate to go with the close to half a sheet I have on hand. So many projects, so little 'extra' time. :) 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
