YASKAWA SGD7S-****20A Series - Page 355

8.12 Additional Adjustment Functions
8.12.8 Backlash Compensation
8
Tuning
8-77
 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.
CAUTION
 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.
Pn231
Pn231
POS
APOS
TPOS0 TPOS1 TPOS2
POS
APOS
Driving in the Forward
Reference Direction
Machine shaft
Motor shaft
Reference travel
distance 1
Reference travel
distance 2
Machine shaft
Motor shaft
Driving in the Reverse
Reference Direction
Backlash compensation value (Pn231)
Machine shaft
Motor shaft
Machine shaft
Motor shaft
Backlash compensation value (Pn231)
Reference travel
distance 2
Reference travel
distance 1
Reference travel
distance 2
Reference travel
distance 1
Servo ON
Target position
Reference travel
distance 1
Target position
Reference travel
distance 2
Target position
Forward reference
direction