Re: Servo control from PC

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "William Scalione"
<wscalione@n...> wrote:

>
>
> > Has anyone had any luck running a servo system directly from a

pc? I

> > have used numerous PCI cards and they work great, but are

expensive.

> > I was wondering if an interface exists for driving the amplifier
> > inputs and receiving encoder inputs from parallel ports. Is Visual
> > Basic or some form of C programming capable of this? I have used
> > Visual Basic as an interface for the PCI motion control cards.
> > I know Geko makes drives capable of running servo motors using

step &

> > direction signals from stepper software. Has anyone done this and

is

> > the performance truely that of a servo system? I'm not looking for
> > top servo performance, but I would like better than stepper can
> > provide.
> > Thanks
> >
>
> If what you are asking is can you hook up your analog servo amps to

the

> parallel port and work some magic with VB or C to run them , the

answer is

> no. Standard servo amps have an analog input of + or - 10V and the

parallel

> port is strictly digital
>
> I as well as others on the list use step and direction servos

driven by

> Geckos and Rutex drives and while I can't speak for the Rutex

drives, the

> performance of the Gecko servo drives is very good. Much much

better than

> steppers in my opinion. I will never use steppers again after using

servos.

> I was never 100% confident that my stepper system was where it was

supposed

> to be. Every time I ran my machine I was always wondering if I just

ruined

> that piece of aluminum because of lost steps. I know others have

got their

> steppers to work well but I never could. Since I got the Gecko

servo drives

> I no longer worry about such things.
>
> John Elson has an interface that hooks to the parallel port and

drives

> standard analog servo drives, although as far as I know it is only

supported

> by EMC.
>
> Bill

Thank you Bill,
I suspected as much. The reason I asked is that I already have
several servo amps. I have an Omnitech Robotics motion card, but am
not real happy with it's performance.
I too will never go back to steppers.
Allen