On 27 January 2011 03:01, Jon Elson <el...@pico-systems.com> wrote: > (For completeness, FF0 is feedforward proportional to position, not a > really helpful > term.)
It seems to me that FF0 would be ideal for a closed-loop spindle speed control PID. The FF0 term gives you the PWM duty cycle directly proportional to speed request, and then you can have an I term to make it accurate. P is no use at all in this case, as setting VFD duty to zero once at speed really doesn't have the right effect :-) -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users