YASKAWA SGD7S-xxxDA0 series Product Manual page 357

9.12 Additional Adjustment Functions
9.12.8 Backlash Compensation
 Operation When the Servo Is ON
The backlash compensation value (Pn231) is added in the backlash compensation direction
when the servo is ON (i.e., while power is supplied to the motor) and a reference is input in the
same direction as the backlash compensation direction (Pn230.0 = n.X). When there is a
reference input in the direction opposite to the backlash compensation direction, the backlash
compensation value is not added (i.e., backlash compensation is not performed).
The relationship between position actual value (6064h) and the motor shaft position is as fol-
lows:
• If a reference is input in the compensation direction: Position actual value (6064h) = Motor
shaft position - Pn231
• If a reference is input in the direction opposite to the compensation direction: Position actual
value (6064h) = Motor shaft position
The following figure shows driving the Servomotor in the forward direction from Target Position
0 (target position: 607Ah) to Target Position 1 and then to Target Position 2, and then returning
from Target Position 2 to Target Position 1 and then to Target Position 0.
Backlash compensation is applied when moving from Target Position 0 to Target Position 1, but
not when moving from Target Position 2 to Target Position 1.
Driving in the Forward
Reference Direction
Driving in the Reverse
Reference Direction
9-74
 The encoder divided pulse output will output the number of encoder pulses for which driv-
ing was actually performed, including the backlash compensation value. If you use the
encoder output pulses for position feedback at the host controller, you must consider the
backlash compensation value.
Servo ON
Target position
Target Position 0
Reference travel
Position demand
value (6062h)
Position actual
value (6064h)
Machine shaft
Pn231
Motor shaft
Machine shaft
Motor shaft
Backlash compensation value (Pn231)
Reference travel
Position demand
value (6062h)
Position actual
value (6064h)
Machine shaft
Motor shaft
Machine shaft
Motor shaft
CAUTION
Target position
Target Position 1
Reference travel
distance 1 distance 2
Reference travel Reference travel
distance 1 distance 2
Reference travel
distance 1 distance 2
Reference travel Reference travel
distance 1 distance 2
Target position
Target Position 2
Forward reference
direction
Pn231
Backlash compensation value (Pn231)