Re: True servo system with STG cards

The term servo is used to describe a system in
which feedback is utilized to help a process
find out if the desired result is achieved. If
the desired result is not achieved, then the
driving force is altered until the result is
correct. This is sometimes referred to as
closing the loop.

With a Gecko, Rutex, or IMService type of servo
drive, this feedback (from an encoder) is monitored
by the motor drive itself. The servo action all
happens within the drive and motor system. The
computer and its software are not involved. This
works reasonably well, but the computer is not
aware of any miss-match between commanded movement
and the movement actually happening unless a limit
switch is hit for the drive signals a fault.

With the EMC software it is possible to run a
servo with the software monitoring the feedback
and adjusting the driving force. This "closed
loop" includes the software, so the software
is fully aware of all movement. To do this
requires an interface that can monitor the
feedback. The STG (Servo-To-Go) interface card
is one of several that can work with EMC to
control servo motors.

Regards,
Steve Stallings
www.pmdx.com


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "shadi_salhab_78"
<salhab@m...> wrote:

>
> Hi all,
>
> I have been looking for EMC requirerments and I faced this "True
> servo system with STG cards" what is a STG card ? and what is meant
> by the word "True "? Is the gecko pulse and direction servo is not
> True?
> Thanks.