Siemens SINAMICS S120 Function Manual page 110

Operating Modes
Servo control
Warning
!
Before using the pole position identification routine, the control sense of the speed
control loop must be corrected (p0410.0).
For linear motors, refer to the Commissioning Manual.
For rotating motors, in sensorless 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.
Pole position determination 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 are:
S One zero mark in the complete traversing range
S Equidistant zero marks whose relevant position to the commutation are identical
S Distance-coded zero marks
Determining a suitable technique for the pole position identification routine
*
be used.
Fig. 3-21
3-110
Can the motor rotate freely
(no external forces)?
Is the motor ironless?
A saturation-based method can
Selecting the appropriate technique
*
Yes
Set operation 1980 = 10
*
Enable pulses and start pole
position identification.
*
Pole position identification is not
Yes possible
*
A mechanically adjusted encoder
with absolute information must be
used.
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition