Siemens Sinamics S120 Function Manual page 112

Servo control
3.13 Pole position identification
● A brake must be available and must also be closed during the pole position identification.
● Parameters p3090 to p3096 must be correctly set for a successful pole position
● The specified current magnitude (p3096) must deflect the motor by a sufficient amount.
● The ratio between the sign of the deflection and the force/torque must be taken into
Before using the pole position identification routine, the control sense of the speed control
loop must be corrected (p0410.0).
For linear motors, see SINAMICS S120 Commissioning Manual (IH1).
For rotating motors, in encoderless operation with a small positive speed setpoint (e.g. 10
rpm), the speed actual value (r0061) and the speed setpoint (r1438) must have the same
sign.
CAUTION
If more than one 1FN3 linear motor is using saturation-based pole position identification for
commutation (p1980 ≤ 4 and p1982 = 1), this can reduce accuracy when the commutation
angle is determined. If a high level of accuracy is essential, (e.g. when p0404.15 = 0 or to
determine the offset of the commutation angle using p1990 = 1), the pole position
identification runs should be carried out consecutively. This can be achieved by staggering
the time at which the individual drives are enabled.
Pole position correction with zero marks
The pole position identification routine provides coarse synchronization. If zero marks exist,
the pole position can be automatically compared with the zero mark position once the zero
mark(s) have been passed (fine synchronization). The zero mark position must be either
mechanically or electrically (p0431) calibrated. If the encoder system permits this, then we
recommend fine synchronization (p0404.15 = 1). This is because it avoids measurement
spread and allows the determined pole position to be additionally checked.
Suitable zero marks
● One zero mark in the complete traversing range
● Equidistant zero marks
● Distance-coded zero marks
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Either the drive controls the brake (p1215 = 1 or 3) or the brake is externally closed well
in advance of the start of the pole position identification and is re-opened after the
operation has been completed.
identification.
account in p3090.0.
WARNING
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
Drive functions