Just to correct my last email... the servo period is running at 10Khz not 100Khz....
Thanks again, Curt On Tue, Feb 7, 2017 at 4:51 PM, Curtis Dutton <[email protected]> wrote: > So Sebastian's suggestion works without a problem. Thanks! With a 100Khz > servo period things work fine. > > Before that I was making progress when I started setting the stepgen max > accel, and max vecloity. Basically the systems starts to resemble a servo > system at that point. I think to make it work properly, a veclocity mode > pid controller would need to go in between the motion component and the > stepgen. > > Because the servo period boost is sufficient for my needs, of course I > will just use that, however for future reference it seems that one can run > hostmot2 at a higher speed. > > On Tue, Feb 7, 2017 at 4:09 PM, Peter C. Wallace <[email protected]> wrote: > >> On Tue, 7 Feb 2017, Curtis Dutton wrote: >> >> Date: Tue, 7 Feb 2017 15:55:32 -0500 >>> From: Curtis Dutton <[email protected]> >>> Reply-To: "Enhanced Machine Controller (EMC)" >>> <[email protected]> >>> To: "Enhanced Machine Controller (EMC)" <[email protected] >>> > >>> Subject: Re: [Emc-users] calling hm2_<BoardType>.<BoardNum>.write + >>> hm2_<BoardType>.<BoardNum>.read at higher rates >>> >>> That is where I'm at right now. My base thread is limited because the >>> >> feedback from hostmot2 only changes at servo rate, and it only updates the >> pwmgen at servo rate as well. >> >> So computing the output value of the pwmgen at the base thread speed is a >> waster of effort.. >> >> If I could read and write hostmot2 faster it would work, but it appears it >> is not designed to do so. >> >> The hostmot2 read and write time's are short enough to work with a base >> thread of 50 us, but there must be something in there that is assuming the >> servo period is 1000 us. >> >> >> >> Not really, 8KHz servo threads are possible on fast PC hardware >> >> The best way to do this with Mesa hardware would be data painting >> firmware/driver/interpreter >> >> >> >> >> On Tue, Feb 7, 2017 at 3:44 PM, andy pugh <[email protected]> wrote: >> >> On 7 February 2017 at 18:28, Curtis Dutton <[email protected]> wrote: >>> > As part of my laser engraver implementation that I have been working >>> on, >>> I >>> > have a raster component that needs to vary the pwmgen output at higher >>> rate >>> > than the servo period. >>> >>> I don't think you can vary the pwm duty cycle any faster than the >>> servo thread rate. >>> The duty cycle calculations are performed in a floating point thread, >>> the base-thread function runs at a constant PWM rate between >>> duty-cycle updates. >>> >>> It is actually possible to run floating-point base-threads, but then >>> you will find that the component that determines the duty cycle would >>> also have to run in that faster thread. >>> >>> Maybe you could run three threads? >>> >>> -- >>> atp >>> "A motorcycle is a bicycle with a pandemonium attachment and is >>> designed for the especial use of mechanical geniuses, daredevils and >>> lunatics." >>> яя George Fitch, Atlanta Constitution Newspaper, 1916 >>> >>> ------------------------------------------------------------ >>> ------------------ >>> 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 >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/emc-users >>> >>> ------------------------------------------------------------ >> ------------------ >> 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 >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> Peter Wallace >> Mesa Electronics >> >> (\__/) >> (='.'=) This is Bunny. Copy and paste bunny into your >> (")_(") signature to help him gain world domination. >> >> ------------------------------------------------------------ >> ------------------ >> 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 >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> > ------------------------------------------------------------------------------ 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
