Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 110)

Manual/MDI Operation Modes
Chapter 4
4-10
2. Place the control in manual mode. Refer to page 4-1.
3. Determine the direction that each axis must travel to reach the home
limit switch. Refer to your system installer on the location of the
home limit switch on a specific machine.
4. Press the <AXIS/DIRECTION> button for the axis and direction to
home. You can select more than one axis at one time. The axis
selected moves at the feedrate under
<SPEED/MULTIPLY> .
Important: If you choose the wrong direction for an axis, it will continue
to travel in the selected direction until it contacts a hard limit and an
overtravel will occur. Refer to chapter 12. Your system installer has the
option to enable some button or switch (typically Cycle Stop) through the
PAL program to abort a jog operation or prevent the user from homing the
axis in the wrong direction. Refer to your system installer’s documentation
for details.
The axis homes by:
The axis moves until it trips its home limit switch, then the axis
decelerates to a stop.
The axis then reverses direction and moves off the home limit switch at
a feedrate specified in AMP.
The controller records the distance to the nearest encoder marker or null
position.
The control then moves in a direction specified in AMP, an amount
equal to the home calibration value, specified in AMP, plus the distance
from the encoder marker or null position.
This locates the machine home position. When the axis reaches this
position, the control resets the position registers to a machine coordinate
value specified in AMP. This establishes the zero point of the machine
coordinate system.
Important: During the machine home operation, softlimits and
programmable zones are not active. All active coordinates offsets are
cancelled.