Re: step/dir inputs to servo controllers

> It appears the Geckodrive is set up to run a servo with stepper motor
> inputs. It is not at all clear to me how this differs from step and
> direction aside from some simple logic changes.
>
> I'd be happy to hear from someone who really understands this.
>
> Bob

Bob:

The Gecko G320 and G340 drives are designed to allow a stepper
controller to run brush DC servomotors. The way it works is to provide
PWM directional DC to move the motor and reads a shaft encoder on the
motor to know where it is.

The logic to do this is not simple. The drive keeps track of step
pluse inputs and looks at the motor encoder. It drives the motor at
such a rate that the pulses from the encoder are equal to the step
input pulses. It also deals with a number of other problems to keep
motion stable. It does all the math to adjust for different encoder
resolutions and the number of step pulse input per turn.

The result is that a stepper controller "thinks" it's driving steppers
when the are really DC servomotors.

Hope this helps;

Ken