Siemens SINUMERIK 840D sl Function Manual page 569

Two milling tools each with a reference point, tool orientation perpendicular to the approach direction
Two milling tools with one reference point with a tool orientation in -y
In the present layout, the tool position $AC_MEAS_TOOL_MASK and approach direction to
the workpiece $AC_MEAS_DIR_APPROACH must be set as follows:
Left-hand tool: Approach direction +x and tool orientation -y
System variable
$AC_MEAS_TOOL_MASK = 0x80 + 0x200
$AC_MEAS_DIR_APPROACH = 0
Right-hand tool: Approach direction -x and tool orientation -y
$AC_MEAS_TOOL_MASK = 0x80
$AC_MEAS_DIR_APPROACH = 1
For both tools
$AC_MEAS_Px_COORD = 1
$AC_MEAS_SET_COORD = 1
Extended Functions
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
8.5 Setting zeros, workpiece measuring and tool measuring
Meaning
Tool position in -y direction + tool length differential
values are included negatively
Approach direction +x
Tool position in -y direction
Approach direction -x
Coordinate system of x-th measuring point = BCS
Coordinate system of the setpoint = BCS
M5: Measurement
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