Siemens Automation System S7-400 User Manual
Page 102

Networking
5-4
Automation System S7-400 Hardware and Installation
A5E00850741-01
Number of Nodes
MPI
PROFIBUS DP
127
127 *
(default: 32)
of which:
1 master (reserved)
1 PG port (reserved)
1 PG port (reserved)
125 slaves or other masters
*
Observe the CPU-specific maximum numbers in the Reference Manual CPU Data
MPI/PROFIBUS-DP Addresses
In order for all nodes to be able to communicate with one another, you must assign
them an address:
• In the MPI network, an MPI address
• A PROFIBUS-DP address in the PROFIBUS-DP network
Default MPI Addresses
The following table shows the default MPI address and the max. MPI address with
which the devices are shipped:
Node (Device)
Default MPI Address
Default Highest MPI
Address
Programming device
0
31
OP
1
31
CPU
2
31
Note
If you change the parameter assignment of the highest MPI address of the MPI/DP
interface, the new address remains set even after memory reset, voltage failure or
removing/inserting the CPU.