5.8 Additional Adjustment Function
5-79
5
Adjustments
Backlash Compensation Time Constant
Set a time constant for a first order lag filter to use when adding the backlash compensation value (Pn231) to
the position reference.
If you set Pn233 to 0, the first order lag filter is disabled.
Note: Changes to the set value are applied when there is no position reference input and the servomotor is stopped. The
current operation is not affected if the set value is changed during servomotor operation.
(3) Related Monitor
The following monitoring parameters provide information on backlash compensation.
(4) Compensation Operation
This section describes the operation that is performed for backlash compensation.
Note: The following figures are for when backlash compensation is applied for references in the forward direction
(Pn230.0 = 0). The following monitoring information is provided in the figures: TPOS (target position in the refer-
ence coordinate system), POS (reference position in the reference coordinate system), and APOS (feedback position
in the machine coordinate system). The monitoring information includes the feedback position in machine coordi-
nate system (APOS) and other feedback information. The backlash compensation value is subtracted from the feed-
back positions in the monitoring information, so it is not necessary for the host controller to consider the backlash
compensation value.
• The backlash compensation value is restricted by the following formula. The specified compensation
is not performed if this condition is not met.
∗
For details, refer to
4.4.3 Electronic Gear
.
Example:
If Pn20E is set to 4, Pn210 is set to 1, the maximum motor speed is 6,000 [min
-1
], and the encoder
resolution is 131,072 (17 bits),
1/4
×
6000/60
×
131072
×
0.00025 = 819.2 [reference units]
⇒
Therefore, the maximum backlash compensation value is 819.2 reference units.
• Do not exceed the upper limit of the backlash compensation value. The upper limit of the backlash
compensation value can be confirmed in Un031.
Pn231
҇
Pn210
Pn20E
Maximum motor speed [min
-1
]
60
×
×
Encoder resolution
×
0.00025
Pn233
Backlash compensation time constant
Classification
Setting Range
Setting Unit
Factory Setting
When Enabled
0 to 65535
0.01 ms
0
Immediately
Setup
Position
Un No.
Displayed Information
Unit
Un030
The current backlash compensation value
0.1 reference unit
Un031
Backlash compensation setting limit value
0.1 reference unit
CAUTION
• The encoder dividing pulse output will output the number of encoder pulses for which driving was actually
performed, including the backlash compensation value. If using the encoder dividing pulse output for posi-
tion feedback at the host controller, must consider the backlash compensation value.