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Rockwell Automation 999 IMC S Class Compact Motion Controller (Cat. No. 4100-999-122) User Manual

Page 110

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Understanding IMC-S/23x Setups

Publication 999-122 - January 1997

Active Homing

Active homing is the most common homing procedure for physical

SERVO

axes. When

ACTIVE

is chosen as the homing procedure, the

desired homing sequence is selected by specifying whether or not a
home limit switch and/or the encoder marker is used for this axis. Active
homing sequences always use the trapezoidal velocity profile. The
available active homing sequences are described below.

Homing Without a Limit Switch or Marker

This is the simplest active homing sequence. When this sequence is
performed, the IMC-S/23x immediately assigns the home position to
the current axis position. This homing sequence produces no axis
motion.

Homing to an Encoder Marker

This active homing sequence is useful for single turn rotary and linear
encoder applications since these have only one encoder marker for full
axis travel. When this sequence is performed, the axis moves in the
specified home direction at the specified homing velocity until the
marker is detected. The home position is assigned to the axis position
corresponding to the marker location, and the axis decelerates to a stop.
The axis then moves back to the home position at the specified return
velocity. The axis motions for this homing sequence are shown below.