Rockwell Automation Publication 2094-UM001J-EN-P - March 2017 241
Configure the Load Observer Feature Appendix D
Table 126 - Load Observer Gain Parameters
The Acceleration Estimate and Torque Estimate signals are read by using 
IDN-435 and P-436, respectively. Definitions for these IDN parameters are 
given in the following table.
Table 127 - Load Observer Output Signals
When load observer and the torque low-pass filter are both enabled, and the 
low-pass filter bandwidth is less than 5 times the load observer bandwidth, 
their interaction can interfere with each other, causing instability. The low-pass 
filter is always limited to a bandwidth under 389 Hz in drive firmware prior to 
revision 1.116. As a result, IDN P-065 was added in drive firmware revision 
1.116 to override the torque low-pass filter bandwidth limiting. The filter is 
also bypassed if the override IDN P-065 is set to 1 and the torque low-pass 
filter bandwidth is set to zero.
Table 128 - Torque Low-pass Filter Bandwidth
Refer to Appendix E on page 253 for more information on changing IDN 
parameter values with read/write messages in the Logix Designer application. 
IDN Name Units Format Value, min Value, max
P:0:432 Load Observer Bandwidth (Kop) Rad/s
16 bit 
unsigned int
0
12,500 
(1)
65,535 
(2)
(1) This value applies to drive firmware revision 1.124.
(2) This value applies to drive firmware revisions later than 1.124.
P:0:433 Load Observer Integral Bandwidth (Koi) Rad/s
P:0:434 Load Observer Feedback Gain (Kof) – 200
IMPORTANT You must validate the input parameter to the message instruction when 
executing message instructions to the attributes in Table 126
.
The value being sent is interpreted by the drive as an unsigned 16-bit 
integer. Attempting to write negative values results in the binary-equivalent 
positive value being used by the drive.
IDN Name Units Format Value, min Value, max
P:0:435 Load Observer Acceleration Estimate Acceleration
32bit 
signed int
-2 
31
2 
31
 -1
P:0:436 Load Observer Torque Estimate Torque
16 bit 
signed int
-2 
15
2 
15
 -1
IDN
P:0:065
Bandwidth in the Logix 
Designer Application
Actual Bandwidth in Drive
0 
(1)
(1) Operation before firmware revision 1.116.
= 0 389 Hz
> 0 Limited to ≤ 389 Hz
1 
(2)
(2) Operation with firmware revision 1.116 or later.
= 0 Filter bypassed
> 0 Limited to ≤ 10,430 Hz