Ahh, thanks Les. I like the simulated encoder option. The best part is it’s as easy as flipping a switch. Unfortunately wiring up the drive is a bit more of an ordeal, although I do have a bunch of steppers and drives as they were what was replaced. If I get desperate I’ll go that route. I’d rather try to use my oscilloscope to take a look at the pulse train if necessary. I hope to be able to test this tomorrow night.
A second question. For velocity mode operation between LinuxCNC and the USC board, do I need to add headroom to any speeds or accelerations? Right now I have the TRAJ section max speeds & accelerations set higher than the max speeds & accelerations on the joints and axes (which are set to be the same, since it’s a trivkins machine). Or should I be setting all max speeds and accelerations to the same numbers (excepting if joint 2/Z might be set lower)? Thanks! Matt > On Jun 30, 2021, at 5:40 AM, Les Newell <[email protected]> wrote: > > John, Matt isn't using a stepgen. The Pico USC board uses it's own step > generator. Stepgen expects a position command. As far as I can tell from the > USC docs the USC step generator expects a velocity command, hence the need > for a PID loop. > > Matt, Do you happen to have a spare stepper and drive kicking about? If so > I'd suggest temporarily hooking it up to one axis. That at least would let > you figure out if the step outputs are doing what you expect. > > I see the USC has an option to simulate an encoder instead of using the > physical encoder. Try this mode with the PID parameters in the Pico systems > example hal files. > > Les > > > On 30/06/2021 05:32, John Dammeyer wrote: >> >> That didn't work for me. I think it was Andy that clued me in that I had to >> have P=0 and FF1=0 to disable the PID part of the LCNC. Since the servo >> drive does it anyway and the acceleration (speed that step pulses change) is >> defined by the INI file. >> >> These are from my Spindle. >> >> MAX_VELOCITY = 50.0 >> MAX_ACCELERATION = 300.0 >> # The values below should be 25% larger than MAX_VELOCITY and >> MAX_ACCELERATION >> # If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger. >> STEPGEN_MAXVEL = 62.5 >> STEPGEN_MAXACCEL = 375.0 >> >> What type of drive is it and can you set the parameters easily? >> >> John >> >> >> >> >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > _______________________________________________ > Emc-users mailing list > [email protected] <mailto:[email protected]> > https://lists.sourceforge.net/lists/listinfo/emc-users > <https://lists.sourceforge.net/lists/listinfo/emc-users> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
