RE: [CAD_CAM_EDM_DRO] True servo system with STG cards

STG (Servo To Go) is a rather expensive i/o card that plugs into a computer
ISA buss.

I would consider the Gecko step/servo system a true servo. It is just that
the control loop is closed by the drive rather that the computer. There is
no reason this couldn't have all the advantages of other servos except
one...the
computer does not know where the machine position is. With something like
an STG with emc the actual position is displayed, and software can use that
information to monitor following error and other parameters.

In the case of emc I would also consider the software control loop more
sophisticated than the step/servo drives, although there is no reason
that always has to be so.

Les
Leslie M.Watts
L M Watts Furniture
Tiger Georgia
(706) 212-0242

Main page:
http://www.lmwatts.com
Engineering:
http://www.lmwatts.com/shop.html
Cnc surplus for sale:
http://www.lmwatts.com/forsale.html
Carved signs:
http://www.lmwatts.com/signwp.html


-----Original Message-----
From: shadi_salhab_78 [mailto:salhab@...]
Sent: Tuesday, December 07, 2004 3:42 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] True servo system with STG cards




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.