Siemens SINUMERIK 840D sl Function Manual page 826

Detailed description
2.3 Coordinate systems
2.3.3 Basic coordinate system (BCS)
Basic coordinate system (BCS)
The basic coordinate system (BCS) consists of three mutually perpendicular axes (geometry
axes) as well as other special axes, which are not interrelated geometrically.
Machine tools without kinematic transformation
BCS and MKS always coincide when the BCS can be mapped onto the MCS withouth
kinematic transformation (e.g., TRANSMIT / face transformation, 5-axis transformation and
up to three machine axes).
On such machines, machine axes and geometry axes can have the same names.
Figure 2-15
42
MCS=BCS without kinematic transformation
Basic logic functions: Axes, coordinate systems, frames (K2)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0