6.7  Compatible Adjustment Function
6-51
6.7.6 Torque Reference Filter
As shown in the following diagram, the torque reference filter contains first order lag filter and notch filters 
arrayed in series, and each filter operates independently. The notch filters can be enabled and disabled with the  
Pn408.
(1) Torque Reference Filter
If you suspect that machine vibration is being caused by the servo drive, try adjusting the filter time constants 
with Pn401. This may stop the vibration. The lower the value, the better the response will be, but there may be 
a limit that depends on the machine conditions.
Torque
 Reference Filter Setting Guide
Use the speed loop gain (Pn100 [Hz]) and the torque filter time constant (Pn401 [ms]) to set the torque refer-
ence filter.
Adjusted value for stable control: Pn401 [ms] ≤ 1000/ (2π × Pn100 [Hz] × 4)
Critical gains: Pn401 [ms] < 1000/ (2π × Pn100 [Hz] × 1)
∗
The filter is disabled if 5000 is set.
Torque  
reference 
before  
filtering 
Torque Related
Function Switch
Pn408
Notch filter  Notch filter 
First order lag filter 
Torque 
reference 
after 
filtering
Second order lag filter 
2nd 
Notch 
Filter 
(Pn40C, 
 Pn40D, and
 Pn40E)
1st Notch 
Filter 
(Pn409, 
 Pn40A,
and Pn40B)
* The 2nd torque reference filter is enabled when Pn40F is set to a value less than 
   5000 and disabled when Pn40F is set to 5000 (factory setting).
* 
Torque 
Reference 
Filter 
(Pn401)
2nd 
Torque 
Reference 
Filter
(Pn40F, 
Pn410)
Pn401
Torque Reference Filter Time Constant
 
Classification
Setting Range Setting Unit Factory Setting When Enabled
0 to 65535 0.01 ms 100 Immediately Tuning
Torque
Pn40F
2nd Step 2nd Torque Reference Filter 
Frequency
 
Classification
Setting Range Setting Unit Factory Setting When Enabled
100 to 5000 1 Hz
5000
*
Immediately Tuning
Pn410
2nd Step 2nd 
Torque
 Reference Filter 
Q Value
 
Classification
Setting Range Setting Unit Factory Setting When Enabled
50 to 100 0.01 50 Immediately Tuning
Torque
Torque