Siemens SINAMICS S120 Function Manual page 613

Yellow Speed controller reference frequency response
Magenta APC closed circuit (load speed/motor speed), p3761 = 3 ms
Green APC open circuit (filter 1 output/motor speed), measured with APC active
Figure 8-42 APC circuit closed
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
8.14 Advanced Position Control (including Active Vibration Suppression)
Function modules
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