Siemens AG, 2003. All rights reserved
SINUMERIK 840Di Manual (HBI) – 06.03 Edition
The NC installed in the 840Di Rack is called S7 FM NCU. To allow communica-
tion between NC and PLC, the following setting are required:
MPI address of the NC: PLC address + 1
Input address and output address: 256
Length of data: 2 (preset, no input possible).
To this aim, open the Properties dialog by double-clicking on the NC in 840Di
Dialog: Properties – S7 FM-NCU
Group: Backplane connection
MPI address: 3 (see Note)
The MPI address of NC and PLC are tightly connected one to another.
MPI addr. of NC = (MPI addr. of PLC) + 1
The input/output address of the NC must be set to 256.
In the case of values other than 256, auxiliary functions provided from the PLC
will no longer be acknowledged to the NC and the parts program execution is
thus no longer continued.
7 PROFIBUS DP Communication
7.3 SIMATIC S7 project