Siemens SINUMERIK 840D sl Function Manual page 693

Two milling tools with one reference point with a tool position opposite to the orientation
In the case of the tool position of two milling tools with one reference point, not only are the
input variables of measurement type 23 evaluated but also the values of the following input
variables:
Approach direction and tool orientation +x
$AC_MEAS_TOOL_MASK = 0x2 +200
$AC_MEAS_DIR_APPROACH = 0
Extended Functions
Function Manual, 03/2009, 6FC5397-1BP10-4BA0
Setting zeros, workpiece measuring and tool measuring
Approach direction and tool orientation -x
$AC_MEAS_TOOL_MASK = 0x40
$AC_MEAS_DIR_APPROACH = 1
Measurement (M5)
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