To answer your servo questions
Servo systems, in this kind of application, are always closed loop.
This is the reason that they don't lose position. The controller is always checking and compensating for the position of the axis.
So, current is being applied to the motor, even when it is in position.
Needless to say, with the cost of servos being much more competitive, I wouldn't use steppers.
The power supply for the servos, really depends on which ones you are using.
In the case of the Gecko drives, they typically all use a common supply.
But in the case of more industrial drives it is common for them to have individual supplies.
I don't know which would be better (USB or Parrallel). But it seems to me that parrallel would be faster because it is not a serial communication.
However, it all depends on how it is being used on a very low level.
Hope this helps. |