> Hi > > I am trying to use the 4th axis on the m5i20 board as the +/-10VDC control > > for a frequency drive > > I have added these lines to my io file: > > #Spindle speed from DAC 03 scale 500 > > newsig spinspeed float > > linksp spinspeed <= motion.spindle-speed-out > > linksp spinspeed => m5i20.dac-03-value > the output on motion.spindle-speed-out will be in the same units as you specify with the S-word in G-code. For example M3S200 will result in motion.spindle-speed-out=200 (or maybe -200, I don't recall... :) > > I added these to the ini file: > > #Spindle > > [AXIS_3] > > OUTPUT_SCALE = 500 > AXIS_3 doesn't have anything to do with the spindle.
You probably want to re-scale the motion.spindle-speed-out before it goes to the DAC pin that accepts values of -10 to +10, For example is +10V would correspond to 3000rpm then you would divide the spindle-speed-out with 3000 and then multiply by 10, so in effect divide by 300. You can do that with a scale comp, something like this: loadrt scale count=1 addf scale.0 slow-thread # ddt-scale == volts/rpm for VFD # 1/300 = 0.003333 net rpm-scale scale.0.gain sets rpm-scale 0.003333 net spindle-speed motion.spindle-speed-out scale.0.in net spindle-speed-DAC scale.0.out <insert_your_dac_pin_here> If your VFD internally has parameters for acceleration and deceleration then you can use those. If it doesn't then it might be a good idea to run the spindle command through a limit component to bound the RPM and acc/deceleration. Anders ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
