>There is an arbitrarily large position jump when the index >pulse is detected. The position counter is set from >whatever has accumulated during the home move to zero. My >PPMC driver detects index_enable going from 1 to 0 and >suppresses any velocity on the next servo cycle. It still >sometimes causes a following error on the next cycle, but >that is somewhat rare. What version of LinuxCNC are you using?
Linuxcnc is 2.9.2 >I'm a bit surprised by this as I have never seen this on a >stepper system before. (I do see it rarely on my PPMC >analog servo machine.) Rotary axes often have much lower >SCALE values than linear, I wonder if that has something to >do with the issue. SCALE value in my case is 233.9181, due to reduction gear for increase output toque. Stepper driver's microstepping is set to 2000puls/rev >I notice your stepgen is on axis # 0, but your encoder is on >axis # 4, which is on a different board than #0. That seems >like an odd way to do things, but should work. On my machine I have Universal PWM controller to run 4 DC servos, and additional USC controller to run 3 additional steppers with "integrated" encoders for rotary axis. So, I added linksp Bindex => pid.4.index_enable now it doesn't trigger following error any more (homing completes successfully), interesting thing is, that on first attempt of homing after fresh starting LinuxCNC I see quite large spike on f-error when hitting index pulse, this large spike doesn't accrue on any more on second attempt of homing or later, only after fresh start and on first one. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
