Re: [CAD_CAM_EDM_DRO] Servo Drive - step multiplier

johncrad wrote:

>Hello all,
>Can someone please tell me the principle behind the use of a step
>multiplier in a step and direction input servo drive such as the
>Geckodrive 340 or the Rutex RT990a. I can understand the rationale in
>the case of a stepper drive and micro-stepping to smooth the motion.
>However this would not appear to be a requirement in the case of
>servos. Hope someone can shed some light on this issue.
>
>

The problem is that software-generated step pulse rates are limited
by CPU speed. If the encoder of a servo requires a higher pulse
rate, you have a problem. The multiplier fixes the problem, but it
causes many limitations. Essentially, it just reduces the microstepping
or encoder resolution to a lower value, to get around the software
limitation.

A much better solution is to either get a faster CPU or switch to
hardware-generated step pulses that can be produced at a much
higher rate.

Jon