On Monday 13 January 2020 05:27:58 andy pugh wrote: > On Mon, 13 Jan 2020 at 05:18, John Dammeyer <jo...@autoartisans.com> wrote: > > I have LinuxCNC with the parallel port configured to create 1kHz on > > PIN14 and DIR on PIN16 out through the PMDX-126. Through my adaptor > > board I can run the Bergerda AC Servo from 135 RPM all the way up to > > 2950 RPM. The PWM to 0V-10V board was only $11.23 Cdn and works > > best with a max of 1kHz. Any higher and the low end won't drop > > below about 500 RPM. [/quote] > > I think that you will have trouble with a 1kHz servo thread and a 1kHz > PWM. > > > That doesn't work for > > setp hm2_7i92.0.pwmgen.00.pwm-freq 1000.0 > > > > How do I set the PWM frequency? Googling hm2_7i92 doesn't turn up > > anything that is helpful. > > The generic docs for Mesa card HAL is here: > http://linuxcnc.org/docs/2.7/html/man/man9/hostmot2.9.html#pwmgen > But to find that you do need to know that the Mesa firmware is called > Hostmot2, and that the docs section exists. > > It should be setp hm2_7i92.0.pwmgen.00.pwm-frequency 1000.0
The 7i90's pwmgen is similar, (I think) and I have the frequency set to 1, with pdm-frequency set at 10000. The comment says that makes it self-smoothing. That setup lets me run the vfd down to 5 HZ, and I've set a top at 200hz as the inductance of that motor makes its coil currents and torque fall off a cliff if I try to go any faster. Thats a 40/1 ratio without moveing the belts. Using a mesa spinx1 pdm->analog for the vfd driver. Low frequency current limits in the vfd are set at the motors FLA. It can run at 5hz for 45 minutes and I can still lay a hand on it. Thats well below 100 rpms at the spindle, around 30 IIRC, without listening to the backgear rumble. Nice... 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
