Yaskawa Sigma II Series Servo System - Manual (Page 299)

Sigma II User’s Manual Chapter 7: Using the Digital Operator
7 - 25
7.2.3 Automatic Adjustment of the Speed and Torque Reference Offset
When speed and torque control are used, the motor may rotate slowly even when 0V
is specified as the analog reference voltage. This occurs when the host controller or
external circuit has a small offset (measured in mV) in the reference voltage.
The Automatic Reference Offset Adjustment Mode automatically measures the
offset and adjusts the reference voltage. It adjusts both the speed and torque
references.
The following diagram illustrates automatic adjustment of an offset in the reference
voltage by the servo amplifier.
After completion of automatic offset adjustment, the amount of offset is stored in the
servo amplifier.
The amount of offset can be checked in the Speed Reference Offset Manual
Adjustment Mode. Refer to 7.2.4 Manual Adjustment of the Speed and Torque
Reference Offset
for details.
The automatic reference offset adjustment mode cannot be used for setting the error
pulses to zero for a stopped servo amplifier when a position loop is formed with a
host controller. In such cases, use the manual reference offset adjustment mode.
Refer to 7.2.4 Manual Adjustment of the Speed and Torque Reference Offset for
details.
The zero-clamp speed control function is available to force the motor to stop while
the zero speed reference is given. Refer to 5.4.3 Using the Zero Clamp Function.
• Automatic adjustment of the speed/torque reference offset must be performed under the servo OFF state .
Offset
Reference
voltage
Reference
voltage Offset
automatically
adjusted in
Servo amplifier
Automatic offset
adjustment
Speed or
torque
reference
Speed or
torque
reference
IMPORTANT