Siemens SINUMERIK 840D sl Function Manual page 786

Positioning Axes (P2)
Brief description
Axes for auxiliary movements are traversed independently of the path axes at a separate,
axis-specific feedrate. In the past, many of these axes were moved hydraulically and started
by an auxiliary function in the part program. With the closed-loop axis control implemented in
the NC, the axis can be addressed by name in the part program and its actual position
displayed on the screen.
Note
"Positioning axis/Auxiliary spindle" option
Axes for auxiliary movements must not be interpolating ("full-value") NC axes. Auxiliary
movements may also be carried out using special axes, which can be obtained using the
"Positioning axis/Auxiliary spindle" option.
Functional restrictions
Optional positioning axes/auxiliary spindles have fewer functions. The following functions are
not possible:
• Using the axis as a path axis, geometry axis, or special path axis
• Incorporating the axis into the geometry axis grouping (GEOAX)
• Rigid thread cutting and tapping
Commissioning
As standard, axes are defined as interpolating axes:
MD30460 $MA_BASE_FUNCTION_MASK bit 8 = 0
If an axis is to be operated as a positioning axis/auxiliary spindle with reduced functionality,
the value for bit 8 must be set to "1":
MD30460 $MA_BASE_FUNCTION_MASK bit 8 = 1
Function
The "positioning axes" function makes it easier to integrate axes for auxiliary movement into
the control system:
● During programming:
● During program testing/start-up:
● During operation:
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The axes are programmed together with the axes for workpiece machining in the same
part program, without having to sacrifice valuable machining time.
There are special (POS, POSA) traversing instructions.
Program testing and start-up are performed simultaneously for all axes.
Operation and monitoring of the machining process commence simultaneously for all
axes.
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Extended Functions