Tom wrote: >Tom <kestrel...@...> writes: > > >>I will look at >>the outputs on the scope tomorrow. Also, I connected my cable shield to power >>ground in the computer ribbon cable, so that may be causing excessive noise >>feedback. >>You have to jumper the Mesa 7i33 for differential inputs, and I think it has >>noise filtering. >> >>Thanks, >>Tom >> >> >Well, I checked the differential encoder outputs on a scope on the machine >while >running, and they are clean as a whistle all the way up to max motor rpm. I >re-routed the cable shield to chassis Gnd instead of power Gnd, and that helped >a little. > > OK, noise reduction is a good thing :) (Incidentally, I was asking about additional external filtering that might have reduced the bandwidth of the signal, not the filtering mode of the 7i33)
>My pyVCP spindle speed bar display (the one that jumps around above 3000rpm) is >linked to "rev-scaled" which runs in a slow thread. I may need to adjust the >thread timing, and route the raw encoder counts through a lowpass filter. > > The newer Mesa drivers have an estimated velocity output, which should be pretty accurate. The scaling (*60) should be able to run in the servo thread just fine. I'm not sure when the velocity output was added, but I'm pretty sure it's in the hostmot2 drivers in EMC2 2.2.8. - Steve ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
