YASKAWA SGD7S Product Manual page 333

8.12 Additional Adjustment Functions
8.12.8 Backlash Compensation
 Operation When the Servo Is OFF
Backlash compensation is not applied when the servo is OFF (i.e., when power is not supplied
to motor). Therefore, the reference position POS is moved by only the backlash compensation
value.
The relationship between APOS and the motor shaft position is as follows:
• When servo is OFF: APOS = Servomotor shaft position
The following figure shows what happens when the servo is turned OFF after driving the Servo-
motor in the forward direction from target position TPOS0 to TPOS1. Backlash compensation
is not applied when the servo is OFF. (The SERVOPACK manages the position data so that
APOS and POS are the same.)
 Operation When There Is Overtravel
When there is overtravel (i.e., when driving is prohibited due to an overtravel signal or software
limit), the operation is the same as for when the servo is OFF (
OFF on page 8-78), i.e., backlash compensation is not applied.
Related Monitoring
You can monitor the following values on the operation monitor of the SigmaWin+.
Input Reference Pulse Speed
Position Deviation
Input Reference Pulse
Counter
Feedback Pulse Counter
Fully-Closed Feedback Pulse
Counter
Feedback Pulse Counter
8-78
Target position
TPOS0
Reference travel distance
POS
APOS
Machine shaft
Pn231
Reference travel distance
Motor shaft
Machine shaft
Motor shaft
Backlash compensation value (Pn231)
Displayed Value
Reference units
Reference units
Encoder pulses
External encoder
Reference units
Servo OFF
Target position
TPOS1
Unit
Displays the input reference pulse speed before backlash
-1
min
compensation.
Displays the position deviation for the position reference
after backlash compensation.
Displays the input reference pulse counter before back-
lash compensation.
Displays the number of pulses from the actually driven
motor encoder.
Displays the number of pulses of the actually driven exter-
resolution nal encoder.
Displays the number of pulses from the actually driven
encoder in reference units.
Forward
reference
direction
Status with no backlash
compensation: POS = APOS

Operation When the Servo Is
Specification