Rockwell Automation 8520 9/Series CNC Lathe User Manual

Page 673

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Skip and Gauge Probing Cycles

Chapter 27

27-5

Important: The move that immediately follows a G37 series skip block

cannot be a circular move.

The system installer determines in AMP if the new value is added to or

replaces the old value in the table. The system installer also determines in

AMP what gauge cycles alter which tool offset tables, geometry, or wear.

The control automatically compensates for probe radius and length when

calculating tool offset changes if these probe parameters have been

entered.

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 and

the probe length if radius and length compensation values were 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 and probe length are defined by the system installer in

AMP. These values may also be changed through the paramacro system

parameters #5096 (for radius) and #5095 (for length).

See the paramacro chapter for details on paramacro parameters.

Tool Gauging Application Example

A typical application for these G-codes in determining tool length offsets

executes as follows:

1.

When the control executes the G37 block, the tool is moved towards

the triggering device using the axis specified in the block.

2.

When the control receives the appropriate skip signal through PAL,

axis motion stops.

3.

The control records the position when the skip signal is received. It

determines the difference by subtracting the position specified with

the axis word in the G37 block from this position. The difference is

then added to or replaces the value in the appropriate geometry or

wear table for the currently active tool offset number.

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