Rockwell Automation 2090 Ultra3000 Installation Manual - Manual (Page 86)

Publication 2098-IN003E-EN-P — April 2004
2-44 Ultra3000 Connector Data
Encoder Phasing
For proper motor commutation and control, it is important that the
motor feedback signals are phased properly. The drive has been
designed so that a positive current applied to a motor will produce a
positive velocity and increasing position readings, as interpreted by
the drive. Additionally, if Hall signals are used to initialize the
commutation angle, the Hall signals must sequence properly and the
phase relationship to the motor back-EMF signals must be understood.
Figure 2.43 shows the proper sequencing of the Hall signals when
positive current is applied to the motor. If the Hall signals are out of
phase with the back-EMF signals, the drive can be configured through
software to compensate for the phase offset, as long as the
sequencing of the Hall signals is correct. Figure 2.44 shows an
example where the Hall signals have an offset of 60 degrees.
Figure 2.43
Sequencing and Phasing of the Hall Signals
Figure 2.44
Sequencing and Phasing of the Hall Signals (60° Hall Offset Example)