YASKAWA SGM-A3 User Manual page 26

FOR FIRST-TIME USERS OF AC SERVOS
1.1.3 Features of Σ -Series Servos cont.
1
12
3) The most common usage of a speed/torque control Servopack is shown below:
• Using Servopack in Speed/Torque Control Mode (Speed Control)
Position reference +
Position
feedback
(Analog
voltage)
As shown in the figure above, a position control loop is formed in the host controller. The
host controller compares a position reference with a position feedback signal and sends
processing results to the Servopack as a speed reference.
In this way, the host controller can freely perform the control required for the servo mech-
anism.
The Servopack undertakes the speed control loop and subsequent control processing.
Yaskawa programmable machine controller PROGIC-8 is available as a typical host con-
troller.
Host controller
Position control loop
Servopack
Speed
(speed/torque control)
reference
Power
amplifier
Torque
(current)
Position Speed
feedback
Convert
Pulse train
Position feedback
Servomotor
Encoder