Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set User Manual
Page 107
Home Parameters
Chapter 5
5-5
Important: If the speed selected here is too great, the axis may move
“through” the home switch before coming to a stop. If the switch changes
from “OFF” to “ON” and then back to “OFF” before the axis can stop, and
the Dir to Move off Limit Switch is the same as the direction moved to
the switch, the control will generate a homing error. This error is
“JOGGED HOME TOO FAST:” and includes the name of the
violating axis.
3.
The axis moves until it trips the home limit switch.
4.
The axis is commanded to stop and the control waits until the
following error is within the range defined by the AMP Inposition
Band parameter.
5.
The axis then proceeds in the direction entered for the parameter
Dir. to Move off Limit Switch at the speed entered for the parameter
Home Speed from Limit Switch. All feedrate overrides are disabled
throughout the rest of the homing sequence.
6.
The axis continues until it comes off the home limit switch, at which
time it is again commanded to stop.
7.
The control waits for the axis to stop, until the following error is
within the range defined by the AMP Inposition Band parameter.
8.
The control calculates the distance to the home position by summing
the distance to the nearest encoder marker plus the distance entered
for the Home Calibration parameter.
9.
The axis moves at Home Speed from Limit Switch to the calculated
home position (this can be in either direction, depending on the result
of the previous calculations).
10. The control defines this position as the home position for the axis,
and assigns it the coordinate value entered for the parameter
Axis Position after Homing.
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 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.