Advertisement
Sigma II User's Manual
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.
Reference
voltage
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 Section 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 Section 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 Section 5.4.3 Using the Zero Clamp
Function.
• Automatic adjustment of the speed/torque reference offset must be performed under the servo OFF state
Follow this procedure to automatically adjust the speed/torque reference offset.
Offset
Speed or
Automatic offset
torque
adjustment
reference
IMPORTANT
7-27
Chapter 7: Using the Digital Operator
Reference
voltage
Speed or
torque
reference
Offset
automatically
adjusted in
Servo amplifier
.
Advertisement
