On Saturday 26 June 2021 12:17:15 Feral Engineer wrote: > Hey John, > > I guess i should've explained better, I was half awake when I asked > that. I'm running dmm servos on my mill, which are currently driven on > a 7i76e with step/dir and are only semi closed loop (closed loop from > the motor to the drive, but not to LinuxCNC). I'm Curious if it's > possible to use the external encoder feedback from the dyn4 to > LinuxCNC to create a full closed loop arrangement using that encoder > and step/dir or do the servos have to be controlled via analog signal > and pid tuning to get the encoder feedback to be closed loop? > > Also, I'm looking for the secret sauce to get full closed loop from my > vfd to LinuxCNC if anyone has pointers on that. I have encoder > feedback to LinuxCNC, but i feel like I'm missing a key element to get > the pid working properly. Most of the adjustments I've made to pid > never result in LinuxCNC compensating for the error (i.e. G97 S200 = > S210 actual with p =0, changing P results in a runaway in most cases). > I'm wondering what the magic net command might be to get everything > working so I could thread on my lathe.
> Phil T. > The Feral Engineer Exchange the A & B signals from the encoder to LCNC, either in the .hal file, or physically, it sounds as if the LCNC PID thinks its running backwards. Check for sure by watching the encoder output with a halmeter, it should be counting up when the motor is turning fwd, and vice-versa. 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
