Siemens sinumerik 840D sl Function Manual page 595

Detailed description
2.1 Speed/torque coupling, master-slave (SW 6 and higher)
Figure 2-2
Each slave axis has exactly one master axis.
Conversely, a master axis can also belong to several slaves; this is done by configuring
several master-slave relationships using the same master axis. A configured slave axis must
not be the master axis in one of the other master-slave relationships.
Figure 2-3
8
Slides (linear motor) for temporary coupling
Four coupling relationships with the same master axis
Special functions: Speed/Torque Coupling, Master-Slave (TE3)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0