Yaskawa Large Capacity Sigma II Series User Manual

Page 245

6.2 Applied Operation

6-25

6.2.3 Automatic Adjustment of the Speed and Torque Reference Offset

When speed and torque control are used, the motor may rotate slowly even when 0 V 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 reference offset automatic 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 SERVOPACK.

After completion of offset automatic adjustment, the amount of offset is stored in the SER-
VOPACK.

The amount of offset can be checked in the speed reference offset manual adjustment mode.
Refer to 6.2.4 Manual Adjustment of the Speed and Torque Reference Offset.

The reference offset automatic adjustment mode cannot be used for setting the error pulses
to zero for a stopped SERVOPACK when a position loop is formed with a host controller.

In such cases, use the reference offset manual adjustment mode. Refer to 6.2.4 Manual
Adjustment of the Speed and Torque Reference Offset.

The zero-clamp speed control function is available to force the motor to stop while the zero
speed reference is given. Refer to 4.4.3 Using the Zero Clamp Function.

Automatic adjustment of the speed/torque reference offset must be performed under the servo OFF
state.

Follow the procedure below to automatically adjust the speed/torque reference offset.

Offset

Reference
voltage

Offset
automatically
adjusted in
SERVOPACK

Automatic offset
adjustment

Speed or
torque
reference

IMPORTANT