Fully-Closed Loop Control - YASKAWA SGD7S Product Manual

8.12 Additional Adjustment Functions
8.12.7 Backlash Compensation
Related Parameters
Set the following parameters to use backlash compensation.
 Backlash Compensation Direction
Set the direction in which to apply backlash compensation.
Pn230
 Backlash Compensation Value
Set the amount of backlash compensation to add to the position reference.
The amount is set in increments of 0.1 reference unit. However, when the amount is converted
to encoder pulses, it is rounded off at the decimal point.
Example
Pn231
Important
8-74
Parameter

n. 0
Compensate forward references.
(default setting)

n. 1 Compensate reverse references.
When Pn231 = 6,553.6 [reference units] and electronic gear ratio (Pn20E/Pn210) = 4/1:
6,553.6 × 4 = 26,214.4 [pulses]
 The backlash compensation will be 26,214 encoder pulses.
Backlash Compensation
Setting Range
-500,000 to 500,000
• The backlash compensation value is restricted by the following formula. Backlash compensa-
tion is not performed if this condition is not met.
Maximum motor speed [min
Pn210

Pn231 ≤
Pn20E
*
Refer to the following section for the encoder resolution.
5.15 Electronic Gear Settings on page 5-41
With fully-closed loop control, substitute the number of external encoder pulses per motor rotation
for the encoder resolution in the above formula.
Example 1:
Pn20E = 4, Pn210 = 1, Maximum motor speed = 6,000 [min
16,777,216 (24 bits)
1/4 × 6,000/60 × 16,777,216 × 0.00025 = 104,857.6 [reference units]
 The backlash compensation will be limited to 104,857.6 reference units.
Example 2:
Pn20E = 4, Pn210 = 1, Maximum motor speed = 6,000 [min
Scale Pitches (Pn20A) = 500, and Use of the JZDP-H00-000 (signal resolution: 1/256):
1/4 × 6,000/60 × (500 × 256) × 0.00025 = 800.0 [reference units]
 The backlash compensation will be limited to 800.0 reference units.
• Do not exceed the upper limit of the backlash compensation value. You can check the upper
limit on the operation monitor of the SigmaWin+.
Meaning
Setting Unit Default Setting
0.1 reference
0
units
-1 ]
 Encoder resolution*  0.00025
60
When Enabled Classification
After restart Setup
Position
When Enabled Classification
Immediately Setup
-1
], and Encoder resolution =
-1
], Number of External Encoder