On Saturday 30 August 2014 12:51:29 Peter C. Wallace did opine And Gene did reply: > On Sat, 30 Aug 2014, Gene Heskett wrote: > > So in the most recent 2.6.2, hal_scope seems to be in need of some > > TLC. > > > > So now I am going to have to concoct some sort of a way to see if I > > can capture this startup dir twiddling on a non-storage scope. > > Doing it 10x a second, I may be able to get the trace bright enough > > to be able to see the direction twiddling bits at the BOB output. > > Fun & games. > > > > Thanks. > > I have noticed that also, when you add a new halscope channel, the > value stays at 0 until you "do something" like changing the run mode > to stop and then back to roll mode > > > Cheers, Gene Heskett
Yes, thats been noted for quite a while. I rarely use the roll mode unless looking at the pid.s.error or something similar. For most of this, I have been triggering on the enable edge on motion.spindle-on. Then I can see the rest of the startup sequence as they occur. But I am not sure if I can read close enough between the lines to set the 5i25's pwm scale. Currently, because the Pico pwm servo driver cannot tolerate a 100% duty cycle, and there is no corresponding pin to the 5i25's pwmgen's to tell them the max duty cycle limit, I am setting the PID.Max_output to a value a few (like 25) less than the pwmgen scale. This prevents it from hitting 100% duty cycles 99% of the time. My no load voltage from this psu/boat anchor is just north of 95 volts, so my top rpms are about 1180 in backgear high, and to drop it below 1180 I have to enter an s1000 on the mdi command line, which slows it to about 1140 revs. But with those same settings, an s50 entry only gets me about 25 rpms. S100, OTOH gives around 105. Setting a pid bias isn't useful as its bidirectional drive, but it needs an ability to run it up to about 10 rpm with nothing more than a valid spindle-on from motion just to overcome friction in either direction. Do you have a URL to a nomograph on tuning a pid for both this and the stepper drives on a lathe? Matching the expected rpms to the pwmgen scale is something I see others doing, but it seems the higher I take these two variables, the more linear the output becomes. But at any scale, they miss-match in favor of a 10 to 20% higher than requested speed. Also for reasonably accurate near=true performance, can someone explain the sort of units near expects on its "difference" pin? All I am getting is an occasional flicker of green which IMO renders that button less than useful. Thanks Peter & anybody else with hints. 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) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
