Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 529)

Fixed Cycles
Chapter 25
25-9
Function
All milling and drilling cycles, lathe and mill controls.
This parameter determines the axis on which drilling operations are
performed. This is the axis that the tool is actually feeding into the part.
Other axes are used to position the cutting tool above the location for the
milling operation. If an axis is selected here for the fixed drilling axis (any
value other than none), the control uses this axis as the hole-machining
axis regardless of the currently active plane.
Selecting None for a Drilling Axis
Selecting none for this parameter allows the part programmer to select the
drilling axis using his choice of plane. When this parameter is set to none,
the drilling axis is always the axis configured as perpendicular to the active
plane. An axis is determined to be perpendicular to a plane if it is in some
other defined plane. For example assume the following plane definition:
G17 (XY), G18 (ZX), G19 (YZ).
With the above plane definition, when the part programmer activates the
G17 plane, the Z axis is determined to be the drilling axis since it is
configured as perpendicular to the G17 plane (i.e. it is not in the active
plane and is in the two planes perpendicular to the active plane). None is
usually selected for mill controls to allow the programmer to select the
hole machining axis by using plane select. Lathe controls typically require
a fixed drilling axis.
Dual Process Controls
For Dual Processing controls, this is a per process parameter. The value set
in the parameters applies to all of the axes assigned to that process.
On Dual processing controls, this is a physical axis number not the axis
number in the process. For example, if axis 6 is the third axis in process
two, and it is the drilling axis, enter axis 6.
Since you can share a drilling axis between processes there is the potential
to have conflicting drilling axes (more than one) in the same process. If
your drilling axis is shared and you have more than one drilling axis in the
system, you should configure none for this parameter in both processes.
This will allow the plane to determine which axis is the drilling axis at any
given time in any given process.
Axis Parameter Number
Single Process Process 1 Process 2
All [26] [20026] [21026]
25.8
Fixed Drilling Axis