Siemens SINUMERIK 840Di Function Manual page 1202

Detailed Description
2.3 Starting up hardware configuration of PLC CPUs
Note
On SINUMERIK 840D, SIMATIC line 0 is allocated for the SINUMERIK components. The
following components are inserted in this line:
The integrated PLC with the various bus systems (slot 2)
An IM 360 (slot 3)
The NCK 840D sl (slot 4). The properties (I/O address 256, process interrupt) of the NCK
must not be changed, otherwise process interrupts (e.g., auxiliary functions) from the NCK to
the PLC will no longer function.
The integrated Ethernet CP 840D sl (slot 5)
The integrated HMI 840D sl (slot 6)
The integrated drive is linked on the internal PCI bus (PROFIBUS protocol).
Currently, this bus does not support I/O access, and SFCs are not supported for this bus.
If you are using a different NCU, you can change the NCU using drag & drop. The settings
remain unaffected.
2-8
PLC Basic Program Solution Line (P3 sl)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0