Re: servo vs stepper

Jon, As I understand it the pulse generator is on a DSP chip on the
motion control board. It is supposedly there outside the computer
where the pulses are generated. The computer just communicates with
the motion board throught the serial port.
Thanks,
Keith

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
> Keith Clark wrote:
>
> >Bob,
> >
> >Mine is a Series I. I will check out the compumotor drives.
Maybe I
> >will never get to 100 ipm but 20 sure is pittiful. I have set
the
> >Geckos to maximum power and have a healthy power supply. It
looks
> >like from the power speed graphs that the motor just needs more
> >juice. I am trying to investigate the pulse generator question.
I
> >have not found a software to test. My motion board connects to
the
> >serial port.
> >
> SERIAL PORT? I'm getting ever more concerned that this is the
problem!
> I really don't know enough about this Galil card, and you had it
checked by
> the manufacturer, but that seems like a real bottleneck. I assume
the
> computer sends a velocity to the board, and the board generates the
> step pulses and keeps count. But, the serial port can only update
the
> velocity so many times a second. (I do it 1000 times a second on
my
> universal stepper controller) so the velocity is ramped up and down
> very smoothly. I seriously doubt they can do it as smoothly with
the
> commands
> going through the serial port.
>
> Jon