Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 117)

Home Parameters
Chapter 5
5-15
These parameters are related to automatic homing:
Parameter: Page:
G28 Direction to Home 5-17
G28 Home Speed 5-18
G30 Secondary Home Position 5-20
G30 3rd Home Position 5-21
G30 4th Home Position 5-22
Automatic homing is similar to manual homing and is described below.
Automatic Homing Sequence
1. To initiate an automatic homing operation, execute a G28 block,
either through the part program, or MDI. In this case, the direction
will be determined by the parameter G28 Direction to Home and the
speed will be determined by the parameter G28 Home Speed. If the
axis was previously homed, the speed will be determined by the rapid
feedrate. All feedrate overrides are disabled throughout an automatic
homing sequence.
2. Once the home limit switch is tripped, homing follows the same
series of events as described in steps 3 through 10 of the Manual
Homing Sequence (refer to page 5-3).
A typical homing sequence is illustrated in Figure 5.1. This figure
assumes that the value entered for the AMP parameter Dir. to Move Off
Limit Switch is opposite of the direction moved to the switch (opposite of
G28 Direction to Home for automatic homing). It also assumes that the
sum of the distance to the nearest marker and the Home Calibration
distance, result in a move in the same direction as Dir. to Move Off
Limit Switch.
5.2
Automatic Homing
Parameters