RE: [CAD_CAM_EDM_DRO] EMC and stepper driver

The servo is not looking at the step signals in the same manner the stepper
is. On the stepper if the pulse train gets unevenly spaced you are very
rapidly accelerating and decelerating the stepper and it will stall. On the
servo you are just loading an accumulator that is driving one side of a
comparator. The other side is loaded by the encoder. If there is a
difference an error signal is generated that drives the servo motor. The
accumulator does not care about the evenness of the pulse as acceleration is
handled by the degree of the error signal, not the rat of the steps. Also, a
servo motor does not have the same sensitivity to acceleration as a stepper.

Tim
[Denver, CO]

> I have stolen the following post from a emc message site.
>
> http://www.nist.gov/itl/div896/emaildir/emc/msg01620.html
>
> It is from our very own Tim Goldstein, and deals with Steppers and
> servos under EMC. acording to Tim the G320 servo drive runs great at
> 30,000 steps per second and steppers with a stepper drive cant run
> any way near this fast.
>
> My question is. Is the front end of the G320 somehow conditioning
> the signal or are servos just more forgiving. If the G320 is
> conditioning the signal then we should ask Mariss at geckodrive to
> put this conditioning in his line of stepper controllers.
>
> Wally K.
>
> FAQ: http://www.ktmarketing.com/faq.html