Siemens SINUMERIK Series Function Manual page 95

Figure 2-9
Requirement
The use of link axes requires a link communication defined in accordance with "Section Link
communication (Page 79)".
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, 03/2013, 6FC5397-1BP40-3BA1
Link axes
B3: Distributed systems - 840D sl only
2.2 NCU link
95