Siemens SINAMICS S120 Function Manual page 259

Note
For encoders, which provide an absolute position (r0404.1 = 1), determining the
commutation angle offset can be deactivated (p1990 = 0).
Pole position identification is only possible at standstill.
If the control mode is only changed over to operation with encoder (p1300 = 21) after the
automatic calculation (p3900 = 3 or p0340 = 3), then pole position identification must be
manually set (p1982 = 1); this assumes that an encoder that requires pole position
identification has been selected (e.g. an incremental encoder with zero mark). This is
indicated by fault F07551.
Pole position correction when rotating (fine encoder calibration)
The accuracy of the determined commutation angle offset (p0431) can be increased using
the encoder fine calibration. The motor must be able to be rotated without any load to do
this.
Fine calibration procedure:
1. Activate the encoder fine calibration (p1905 = 90).
Alarm A07976 with alarm value 1 is displayed.
2. Set the pulse enable and accelerate the motor (n > 40% rated speed)
3. Wait for the end of the measurement (alarm A07976 with alarm value 4, takes
approximately 1 minute) and then switch off the drive.
The measurement is restarted if, during the measurement, an excessively low current
flows (alarm A07976 with alarm value 12) - or if the speed is too low (alarm A07976 with
alarm value 10), then the measurement is restarted.
4. After the pulse inhibit, the value is calculated and saved to parameter p0431 - assuming
that it had been successfully completed (alarm A07976 with alarm value 5).
0 is automatically written to p1905, and alarm A07976 disappears.
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Vector control
5.14 Pole position identification
259