Siemens SINUMERIK 840D sl Function Manual page 99

Figure 3-9
Requirement
The use of link axes requires a link communication defined in accordance with "Section Link
communication (Page 83)".
Home NCU
The home NCU of a link axis is the NCU on which it is physically connected as machine axis.
The position control and the exchange of axial NC/PLC interface signals of a link axis always
occurs on the home NCU. The generation of the setpoint can in principle be performed on any
NCU of the link group.
In the above figure:
● NCU1: Home NCU of machine axis MA1
● NCU2: Home NCU of machine axis MA2
Extended Functions
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Link axes
B3: Distributed systems - 840D sl only
3.2 NCU link
99