On 31 March 2014 19:08, Florian Rist <fr...@fs.tum.de> wrote: > A small DC motor with encode, now connected to a 7i39 and controlled via > a 5i23. Currently the drive is set-up as a angular axis A. See the > "Improvised DC Motor Control using Mesa 7i39?" Thread.
I would suggest a second PID controller set up so that the feedback is from the encoder velocity pin. Connect both PIDs to a mux2 HAL component and switch between them that way. Preventing LinuxCNC from triggering a following error is actually the hard part. The simplest solution is probably just to short-circuit the feedback in HAL (net feedback-loop axis.3.motor-pos-cmd => axis.3.motor-pos-fb ) The right way to do it is probably to add the PID error to the position command then feed it back, but some masking using more muxes is likely to be necessary. An alternative might be to use the "offset" component. You could potentially feed the offset pin from a sum2 component looped into itself and controlled from a G-code output (or the spindle speed, if you aren't using it). net sum2-loop sum2.0.out => sum2.0.in0 offset.0.offset net vel-cmd sum2.0.in1 <= motion.analog-out-00 -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
