Siemens SINUMERIK 840D sl Function Manual page 668

Measurement (M5)
8.4 Setting zeros, workpiece measuring and tool measuring
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
668
Approach direction and tool orientation -x
$AC_MEAS_TOOL_MASK = 0x40
$AC_MEAS_DIR_APPROACH = 1
Function Manual, 01/2008, 6FC5397-1BP10-3BA0
Extended Functions