Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 671)

Skip and Gauge Probing Cycles
Chapter 27
27-3
Important: The move that immediately follows a G31 series external skip
block cannot be a circular move.
The coordinates of the axes when the external skip signal is received are
available as the paramacro system parameters #5061--#5066 (work
coordinate system) and #5071--#5076 (machine coordinate system). These
values will have been adjusted to compensate for the probe tip radius if a
radius compensation value was entered.
For example, assume you have entered a probe tip radius of .01. It is
triggered as axis 2 approaches in the positive direction at the axis 2
coordinate of 1.1200. The value available for paramacro parameter #5072
would be 1.1300
Probe tip radius is defined by the system installer in AMP. This value may
also be changed through the paramacro system parameter #5096.
See the paramacro chapter for details on paramacro parameters.
Skip Function Application Example
A typical application for these G-codes would be to mount the probe as if
it were a tool. When the probe contacts the part and triggers, coordinate
data would be available in the paramacros for use in the remainder of the
part program.
The probe tip radius would be significant for this application.
Tool gauging functions are similar to external skip functions. The key
difference is that the tool gauging cycles use the actual tool position (when
the external skip signal is received) to enter values in the tool offset table
for the currently active offset.
Use tool gauging functions to terminate the execution of motion commands
in a block and modify offset tables when the control receives a signal
through PAL. When the program block is terminated any remaining axis
motion generated by the block that has not been performed remains
unexecuted (other non-motion commands are still performed). The current
tool position is stored, and the control continues program execution at the
beginning of the next block following the skipped block.
The gauging function is controlled by G37, G37.1, G37.2, G37.3, and
G37.4. The system installer determines what signal (such as a touch probe,
manual switch, etc.) corresponds to each G37 code in PAL. The system
installer can choose different signals to correspond to G37, G37.1 G37.2,
G37.3, and G37.4. G37 and G37.1 are functionally the same, always
using the same external signal and the same AMP-defined feedrate.
27.2
Tool Gauging External Skip
Functions (G37 codes)