Siemens SINAMICS S120 Function Manual page 260

Vector control
5.14 Pole position identification
Pole position correction with zero mark
When switching on for the first time, the pole position identification roughly synchronizes the
encoder angle to the pole position. After passing the zero mark, this coarse synchronization
is aligned assuming that the encoder supports commutation with zero mark (r0404.15 = 1).
The commutation angle must be available to do this (p0431). In order to utilize fine
synchronization for synchronous reluctance motors, the encoder must support commutation
with 180° (r0459.23 = 1).
Note
If an encoder with zero mark is used, then the converter can switch to a rotating motor as
soon as a valid zero mark position is available.
For synchronous reluctance motors, also when switching on the first time after the power
returns, the converter can be switched to a rotating motor - assuming that the "Flying restart"
function has been activated (p1200 = 1).
Replacing an encoder
If the encoder is replaced or retrofitted, the commutation angle offset must be determined
again (p1990 = 1), assuming that the encoder has position information (e.g. zero mark).
Checking the plausibility of the commutation angle
When using an absolute encoder, with the pole position identification, the plausibility of the
encoder commutation position can be checked (p1980 = 2). With this setting, each time that
the pulses are enabled, the encoder angle is checked. The determined angular difference
can be read out from parameter r1984. Fault F07413 is output if the deviation exceeds 45°.
If mechanical changes are carried out at the encoder, then using the encoder adjustment,
the commutation angle offset can be checked (p1990 = 2). The commutation angle offset is
determined, and the determined value is not accepted (p0431). Fault F07413 is output if the
deviation exceeds 6°.
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Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions