On Tuesday 10 July 2012 23:59:04 Kasey Matejcek did opine: > It set to 1000 > setp ppmc.0.pwm.03.scale 1000 > > when you watch ppmc.0.pwm.03.value it changes from 1000 to -1000 and > back and forth it goes > when I set s 50 rpm then after some time ppmc.0.pwm.03.value goes to > like 50 after some time but it still surges up and down and so does the > number if left long enough ppmc.0.pwm.03.value goes to 0 or some really > small number when the rpm is set lower than 100rpm but really never get > stable above 100 rpm it just keeps surging up and down
One other question might be in order here, just to remove the possibility of a hidden low frequency pole in the feedback loop, what are you using for an interface between the pwmgen output, and the spindle motors own controller? I ask because I've used both the cnc4pc c41 interface, and the PMDX-106. The C41 is slow, and would work ok for non-active speed control, but its slow response when used in an active speed control setup will make tuning it problematic. For active speed control, I believe the PMDX-106 will be markedly more "stable" due to its faster response. The surging could be caused by the output capacitor in the conversion circuit being too large, so when an underspeed error is seen, it will rapidly charge that capacitor, which will speed up the motor, and hold it at that higher speed until the capacitor discharges, slowing the motor, which goes underspeed, which causes that capacitor to be recharged too high, repeat till the power is cut. Basically, that capacitor must be capable of being charged/discharged quicker than the motor can follow commands in order for it to be stable. > -----Original Message----- > From: andy pugh [mailto:bodge...@gmail.com] > Sent: Tuesday, July 10, 2012 5:15 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Spindle hooked to dc servo amp > > On 10 July 2012 23:04, Kasey Matejcek <someo...@lkm.bz> wrote: > > setp pid.3.maxoutput 1000 > > What is the pwm scale? If that is 0-1 and your PID is 0-1000 then you > will have problems. > > -- > atp > If you can't fix it, you don't own it. > http://www.ifixit.com/Manifesto > > ------------------------------------------------------------------------ > ---- -- > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and threat > landscape has changed and how IT managers can respond. Discussions will > include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------------------ > ------ Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. > Discussions will include endpoint security, mobile security and the > latest in malware threats. > http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! You will be given a post of trust and responsibility. ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
