YASKAWA SGD7S-1R9D Product Manual page 331

 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.
 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 (6064 hex) and the motor shaft position is as fol-
lows:
• If a reference is input in the compensation direction: Position actual value (6064 hex) = Motor
shaft position - Pn231
• If a reference is input in the direction opposite to the compensation direction: Position actual
value (6064 hex) = Motor shaft position
The following figure shows driving the Servomotor in the forward direction from Target Position
0 (target position: 607A hex) to Target Position 1 and then to Target Position 2, and then return-
ing 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.
Servo ON
Target position
Target Position 0
Driving in the Forward
Reference Direction
Position demand
value (6062 hex)
Position actual
value (6064 hex)
Machine shaft
Motor shaft
Machine shaft
Motor shaft
Driving in the Reverse
Reference Direction
Position demand
value (6062 hex)
Position actual
value (6064 hex)
Machine shaft
Motor shaft
Machine shaft
Motor shaft
CAUTION
Target position
Target Position 1
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
8.12.7 Backlash Compensation
Target position
Target Position 2
Forward reference
direction
Reference travel
distance 2
Pn231
Backlash compensation value (Pn231)
8
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