On Tuesday 29 December 2015 09:59:34 lloyd wilson wrote: > I'm trying to add a pyvcp panel to control a spindle vfd. To take > advantage of the 'at-speed' signal from the vfd to inhibit motion > until ready, the motion component of LCNC needs to be aware of the > spindle command state- from the documentation: > > *motion.spindle-at-speed* IN BIT > > Motion will pause until this pin is TRUE, under the following > conditions: before the first feed move after each spindle start or > speed change; before the start of every chain of spindle-synchronized > moves; and if in CSS mode, at every rapid->feed transition. > > but I can't find a reference to HAL input pins for spindle control in > the motion control component documentation. Is that communication done > by other methods (NML??- gasp!). > > Can someone point me to a sample configuration that properly > integrates an 'at-speed' signal into LCNC? > > Thanks in advance > > -ldw
I used a near module to develop an at-speed on my lathe. Grepping for near in the .hal files shows this: gene@lathe:~/linuxcnc/configs/my_LinuxCNC_machine2$ grep near *.hal my_LinuxCNC_machine2.hal:loadrt near names=near.speed my_LinuxCNC_machine2.hal:addf mult2.buttonscale servo-thread # s/b in front of near.speed my_LinuxCNC_machine2.hal:addf near.speed servo-thread my_LinuxCNC_machine2.hal:net spindle-velocity sumenc.out pid.s.feedback near.speed.in2 my_LinuxCNC_machine2.hal:net spindle-drive0 motion.spindle-speed-out-rps rvsaccel.in near.speed.in1 my_LinuxCNC_machine2.hal:net spindle-at-speed near.speed.out motion.spindle-at-speed my_LinuxCNC_machine2.hal:# near.speed.in1 is from pid.s.command my_LinuxCNC_machine2.hal:net spindle-at-speed <= near.speed.out my_LinuxCNC_machine2.hal:setp near.speed.scale [SPINDLE_9]NEAR_SCALE my_LinuxCNC_machine2.hal:setp near.speed.difference [SPINDLE_9]NEAR_TOL and a grep for at-speed: gene@lathe:~/linuxcnc/configs/my_LinuxCNC_machine2$ grep at-speed *.hal Gearchange_snippet.hal:# sets spindle-at-speed true my_LinuxCNC_machine2.hal:net spindle-at-speed near.speed.out motion.spindle-at-speed my_LinuxCNC_machine2.hal:net spindle-at-speed <= near.speed.out pyvcp_options.hal:net spindle-at-speed => pyvcp.spindle-at-speed-led sumenc.out is the output stage of a lashup that sums the last 4 encoder samples and outputs the average, a de-noising technique I have cobbled up. It lets me run higher gains in pid.s and results in a quite stiff maintenance of the spindle speed even at speeds down to about 60 rpm without rattling the gear clearances in the backgear too badly as the encoder slots go by. The fly in that soup is there is not a signal I can get directly from a Mesa 5i25 card that indicates an edge has gone by, so I save the last velocity reading, and declare an edge clocking pulse if the next reading has changed by more than a couple counts. It probably miss-fires at the higher rpms, missing an edge here and there as the shop made encoders slots are going by faster than the servo-thread can read it, but by 500 rpm, inertia takes over and the speed control remains quite stiff. I hope its helpfull. 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> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
