Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 495)

Tool Control Functions
Chapter 20
20-11
The random tool feature is typically used to speed up production by saving
cycle time when a tool is returned to the tool changing device. This is
done by allowing the tool changer to randomly return the cutting tool to the
most convenient pocket in the tool changing device. The control will
remember what pocket the tool is returned to and be able to call the same
tool from the new pocket at any time.
Important: This feature may be used with normal tool selection, or the
tool life management feature if desired.
This feature has no effect on tool length offsets or cutter compensation.
These features must still be activated correctly as described in their
individual sections.
The random tool feature will automatically decide the pocket (or pockets)
that contains the requested tool based on the information in the pocket
assignment table. If the requested tool has not been assigned to a pocket
the control will generate an error.
Based on the current pocket number, which is maintained by PAL, the
control will tell PAL which pocket to move too and how far and in which
direction to move. The control will also tell PAL where the tool currently
in use can fit in the tool turret.
Important: This feature is very PAL dependant. Before using this feature
make sure the system installer has written the PAL program to allow the
use of Random Tool.
The control will automatically update the tool pocket assignment table
when tool changes are made. The control will indicate to PAL the best
location to return the tool to. PAL then decides based on this information
where the tool gets placed in the tool holder. The pocket that is vacated by
the new tool is marked as empty.
20.3
Random Tool