Siemens SINUMERIK 840D sl Function Manual page 85

NCU link and Safety Integrated
The following figure shows a constellation with two NCUs and two machine axes, of which the
MA2 machine axis of the NCU2 is traversed as link axis for NCU1. The Safety Integrated
function monitors the safety-related aspects of both axes.
Figure 3-5 NCU link and Safety Integrated
The safety-related input signals (F_DI) of both NCUs can be acquired, linked via the safe
programmable logic (SPL) and exchanged using the safety-related CPU-CPU communication
(FSend/FRecv).
As part of the Safety Integrated function, the NCU-link communication permits the single-
channel non-safety-related transfer of link axis data for Safety Integrated-supporting functions.
Examples:
● Interpolatory braking for an implicit Stop D of all traversing axes, including the link axes, in
the channel.
● Reduce the speed of all axes traversing in the channel, including link axes, for a change
of the safe speed.
Extended Functions
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
B3: Distributed systems - 840D sl only
3.2 NCU link
85