I/O address range
of the NC
Siemens AG, 2003. All rights reserved
SINUMERIK 840Di Manual (HBI) – 06.03 Edition
After the dialog has been quitted, the DP slave PP72/48 is inserted into the DP
master system. Inserting of the detail view makes visible DP slave PP72/48 in
the station window.
The I/O addresses are assigned by "HW Config" automatically. These I/O ad-
dresses should be modified in view of the following supplementary conditions:
I/O address range of the NC
Selective access to the input/outputs by the PLC.
For compatibility reasons and for future system expansions, the I/O addresses
256–271 should not be assigned.
In the case of I/O addresses > 256, the PLC cannot access the individual input/
outputs. The input/output data must first be copied to internal flags of the PLC.
To this aim, use the system functions SFC14 and 15.
For the reasons above, it is recommended to assign the I/O addresses to the
range between 0 and 255.
7 PROFIBUS DP Communication
7.3 SIMATIC S7 project