Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set User Manual
Page 105
Home Parameters
Chapter 5
5-3
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 determines the distance to the nearest null (item
HM DIST displayed on the AXIS MONITOR screen). The control
then verifies if the distance to the nearest null is within tolerance.
Important: The value of the HM DIST item should be as close to 0 as
possible to avoid nuisance “HOME TOLERANCE EXCEEDED” error
messages trips. To reduce its value, adjust either the home limit switch or
the trip dog.
Important: The control does not verify whether the distance to the nearest
null is within tolerance when using A Quad B with One Marker devices.
Home Operation Is:
When Distance to Nearest Null is:
Within Tolerance
less than or equal to 3/8 of the distance of an electrical
cycle on either side of the null
Out of tolerance
greater than 3/8 of the distance of an electrical cycle on
either side of the null
Important: Encoder devices have one electrical cycle per turn, whereas
resolver devices typically have two electrical cycles per turn.