Yaskawa Sigma Mini - Manual (Page 145)

3.2Applications
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3.2.4 Reference Offset Automatic Adjustment
When a Servomotor for speed/torque control is used, the motor may rotate slowly when the
reference voltage is intended to be 0 V. 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 ad-
justs the reference voltage. It adjusts both speed and torque references.
The Servopack will automatically adjust an offset in the reference voltage from the host con-
troller or external circuit, as shown in the following diagram.
Reference
Voltage
Reference
Speed or
Reference
Torque
Offset
Automatic Adjustment
of Offset
Reference
Voltage
Offset
Automatically
Adjusted in
Servopack
Reference
Speed or
Reference
Torque
After completion of offset automatic adjustment, the amount of offset is stored in the
Servopack.
The amount of offset can be checked in the speed reference offset manual adjustment mode.
Refer to 3.2.5 Reference Offset Manual Adjustment for details.
The reference offset automatic adjustment mode cannot be used if the error pulses are set to
zero when the servo lock is stopped and a positioning loop is formed with the host controller.
Under these conditions, use the reference offset manual adjustment mode. Refer to 3.2.5
Reference Offset Manual Adjustment Mode for details.
The motor can be forced to a stop when the speed reference is zero by using the zero-clamp
speed control function. Refer to 2.4.2 Zero-clamp for details.
Reference Offset Automatic Adjustment Procedure
Use the following procedure to automatically adjust the reference offset.
1) Set the motor to operating mode as fol-
lows:
Input the (intended) 0 V reference voltage
from the host controller or external circuit.
Turn ON the servo ON (/S-ON) signal.
3
Host
Controller
0 V Speed
Reference
or Torque
Reference
Servo ON
Servomotor
Slow Rotation
Servopack