Peter C. Wallace wrote: > On Wed, 11 Jul 2012, Jon Elson wrote: > > >> Date: Wed, 11 Jul 2012 12:37:03 -0500 >> From: Jon Elson <el...@pico-systems.com> >> Reply-To: "Enhanced Machine Controller (EMC)" >> <emc-users@lists.sourceforge.net> >> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> >> Subject: Re: [Emc-users] Spindle hooked to dc servo amp >> >> Kasey Matejcek wrote: >> >>> Yes the ppmc.0.pwm.00-03.freq 50000 >>> After playing some time I've come up with this it responds from 2 rpm to 14 >>> rpm when you set s this give and accual spindle speed from about 35 to 75 >>> rpm >>> But there is no to little control if load is applied to the spindle >>> As soon as any p,I,g are added then it unstable surging up and down >>> >>> >> Sure, with FF0 only, it is still an open-loop speed control. it is even >> possible you >> have the phase of the servo loop backwards. You might try a negative >> value in >> P and see if it helps control it under load. If so, then your P, I and >> D values >> should all be negative. >> >> Jon >> > > Danger Will Robinson! > > The PID loop has a bug (feature) and can run-away with negative > coefficients > OK, in that case he needs to reverse the motor terminals or set the OUTPUT_SCALE to -1.0 and see if the control works better.
Jon ------------------------------------------------------------------------------ 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
