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6   Applied Functions
OMNUC G5-series (Pulse-train Input Type) AC Servomotors and Servo Drives User’s Manual
6-13  Friction Torque Compensation Function
6
6-13-3  Operation Example
Torque Command Value Offset (Pn607) reduces the variations of positioning operations due to the 
movement directions when a certain amount of unbalanced load torque is always applied to the motor 
at the vertical axis by setting the torque command value.
By setting the friction torque for each rotation direction in Forward Direction Torque Offset (Pn608) and 
Reverse Direction Torque Offset (Pn609), you can reduce the deterioration of and inconsistencies in the 
positioning stabilization time due to dynamic friction for loads that require a large amount of dynamic 
friction torque due to a radial load, such as the belt-driven shaft.
Precautions for Correct UsePrecautions for Correct Use
You can use unbalanced load compensation and dynamic friction compensation together or 
separately. Take note that the following use limit is applied upon control mode switching or servo 
ON.
• When servo is OFF in speed control
Unbalanced load compensation is enabled based on Pn607. Dynamic friction compensation 
will be 0 regardless of the parameter setting.
• When servo is ON in position control
The unbalanced load compensation and dynamic friction compensation values are held until 
the first position command is input. Once the position command is input, the unbalanced load 
compensation value is updated based on Pn607. Also, based on the command direction, the 
dynamic friction compensation value is updated according to the parameter Pn608 or Pn609.
6-13-3 Operation Example
Command speed
Time
Motor 
de-energized
Motor power supply
Motor 
de-energized
Pn607 
(Torque Command 
Value Offset)
Forward direction
Reverse 
direction
Pn608 
(Forward Direction Torque Offset)
Pn609 
(Reverse Direction 
Torque Offset)