On Wednesday 14 March 2018 14:42:30 Mark wrote: > On 03/12/2018 09:27 AM, andy pugh wrote: > > I think you would need to look to be certain. > > http://linuxcnc.org/docs/2.7/html/man/man9/motion.9.html > > I think that axis.0.joint-pos-cmd is likely, but motor-pos-cmd might > > be the one. I think you want the one that does change on homing. > > Stepping back a few days worth of emails, I finally got a chance to > get out to the shop and look at this. Before I show my results, > something I forgot to mention earlier on is that although it's a 2 > axis machine, I'm using three drives/steppers. Axis.0 is the primary > X axis, with Axis.1 slaved to it. Axis.2 is the single Z axis. > > I powered up linuxcnc and the machine and used Halmeter to observe the > pins and their values during homing like Andy mentioned above. > Unfortunately,both of those sets of pins on the X and Z axis change > during homing from their original value to something different. Here's > the values the pins showed after homing (I didn't think to record the > values prior to homing, but they were different than noted before): > > axis.0.joint-pos-cmd - 3.105958e-09 > axis.0.motor-pos-cmd - 0.000327 > > axis.2.joint-pos-cmd - 2.4 > axis.2.motor-pos-cmd - -6.183435e-05 > > The axis.2.joint-pos-cmd value of 2.4 is what shows on the Axis DRO > after homing. I'm taking a SWAG that the axis.0.joint-pos-cmd equates > to the 0.0 shown on the Axis DRO after homing, but is accurate to more > places than what the DRO shows? At any rate, should I be using the > joint or the motor pos-cmd? > > A Halmeter question - is it possible to run multiple instances of > halmeter so that I can observe different pin's values and compare, > say, the original Z position, the offset, and the final Z position > after the offset is applied? That would be handy to make sure I've > got the negative values correctly and also to see if the hal code is > actually doing what I want it to do.
Yes you can Mark, the only limit I am aware of is screen real estate to display them. Just pull down the menu and click halmeter to start another. > Here's what I've got so far for the hal coding using lincurve and > offset. The x,y values section is just padding currently using the > examples John K posted the other day, and will be replaced with the > real values once I finally determine my breakpoints. > > loadrt lincurve > loadrt offset > addf offset.0.update-output > > setp lincurve.0.x-val-00 0 > setp lincurve.0.y-val-00 0 > setp lincurve.0.x-val-01 4 > setp lincurve.0.y-val-01 0 > setp lincurve.0.x-val-02 5 > setp lincurve.0.y-val-02 -0.002 > setp lincurve.0.x-val-03 6 > setp lincurve.0.y-val-03 -0.003 > setp lincurve.0.x-val-04 13 > setp lincurve.0.y-val-04 -0.003 > setp lincurve.0.x-val-05 14 > setp lincurve.0.y-val-05 0.000 > setp lincurve.0.x-val-06 15 > setp lincurve.0.y-val-06 0.001 > setp lincurve.0.x-val-07 21 > setp lincurve.0.y-val-07 0.001 > > net axis.0.joint-pos-cmd offset.0.in > net lincurve.0.out offset.0.offset > net z-raw axis.2.joint-pos-cmd offset.0.in > net z-corr lincurve.0.out offset.0.offset > net z-cmd offset.0.out stepgen.2.pos-cmd > net z-pos-fb-raw stepgen.2.pos-fb offset.0.fb-in > net z-pos-fb-offs offset.0.fb-out axis.2.joint-pos-fb > > > Andy helped me out with a bunch of this stuff so some of it's copied > and pasted from his emails with minor edits to get the correct axis > numbers. In light of the top part of this email, is this correct? Did > I leave anything out? Is anything superflous? > > Thanks, > Mark I'll leave that last to Andy. -- 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
