YASKAWA SGD7S Product Manual page 332

 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 direc-
tion, the backlash compensation value is not added (i.e., backlash compensation is not per-
formed).
The relationship between APOS and the motor shaft position is as follows:
• If a reference is input in the compensation direction: APOS = Motor shaft position − Pn231
• If a reference is input in the direction opposite to the compensation direction: APOS = Motor
shaft position
The following figure shows driving the Servomotor in the forward direction from target position
TPOS0 to TPOS1 and then to TPOS2, and then returning from TPOS2 to TPOS1 and then to
TPOS0.
Backlash compensation is applied when moving from TPOS0 to TPOS1, but not when moving
from TPOS2 to TPOS1.
Servo ON
Target position
Driving in the Forward TPOS0
Reference Direction
POS
APOS
Machine shaft
Motor shaft
Machine shaft
Motor shaft
Driving in the Reverse
Reference Direction
POS
APOS
Machine shaft
Motor shaft
Machine shaft
Motor shaft
Target position
TPOS1
Reference travel Reference travel
distance 1 distance 2
Pn231
Reference travel
distance 1
Backlash compensation value (Pn231)
Reference travel Reference travel
distance 1 distance 2
Reference travel Reference travel
distance 1 distance 2
8.12 Additional Adjustment Functions
8.12.8 Backlash Compensation
Target position
TPOS2
Forward reference
direction
Reference travel
distance 2
Pn231
Backlash compensation value (Pn231)
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