Installation manual

Appendix B 08/04 Danaher Motion Kollmorgen
98 M-SS-001-01 Rev. T SERVOSTAR S Installation
B.1.2 SERVOSTAR ENCODER TYPES
The idea of obtaining velocity or position information from the series
of pulses generated from the encoder is not difficult to understand.
Permanent magnet brushless DC servo motors require
commutation. As stated earlier, commutation is simply the
positioning of the electromagnetic fields in alignment with the
permanent magnet fields such that optimal torque is produced. This
requires that the motor shaft position be known at all times. The
use of incremental encoders requires some form of initialization to
determine this motor shaft position at power up. It is this
commutation initialization process that can lead to confusion.
Since the SERVO
STAR supports operation with many encoder
types, it must be told which signals to expect to see and which
initialization algorithm to perform. This is the purpose of the
MENCTYPE variable. The following section explains the
MENCTYPE variable and its setting for each encoder type. The
next figure shows the initialization flow chart for the various
MENCTYPEs.
MENCTYPE 0
Read Hall Codes
Establish
Commutation
Angle as though in
the middle
Marker Channel
Occur?
Hall Code Change?
Adjust
Commutation
Angle
Marker Channel
Occur?
Establish new
Commutation using
MENCOFF
End
YesNo
No
Yes