Yaskawa Large Capacity Sigma II Series - Manual (Page 25)

1.3 Features of Σ-ΙΙ Series Servos
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1.3.2 Using the SGDH SERVOPACK
„ Using the SERVOPACK for Speed Control
The most common use of a SERVOPACK for speed control is shown below:
As shown in the above figure, a position control loop is formed in the host controller. The
host controller compares a position reference with a position feedback signal and sends the
processed result to the SERVOPACK as a speed reference.
In this way the host controller can be freed from performing the servo mechanism control.
The SERVOPACK undertakes the speed control loop and subsequent control processing.
The Yaskawa machine controller MP920 is used as a typical host controller.
Host controller
Speed
reference
SERVOPACK
(speed control mode)
Power
amplifier
Speed
Convert
Pulse train
Servomotor
Position feedback
Encoder
Position
feedback
Position control loop -
- -
+ +
Torque
(current)
feedback
Position
Position reference+
(Analog
voltage)