Siemens SIMATIC S7-400 Manual page 34

Structure of a CPU 41x
2.9 Multipoint Interface (MPI)
MPI interface as a PROFIBUS DP interface
You can also configure the MPI interface for operation as a PROFIBUS DP interface. To do
so, you can reconfigure the MPI interface under STEP 7 in HW Config. You can use this to
set up a DP line consisting of up to 32 slaves.
Reference
You can find information about planning time synchronization in the manual
System PCS7; Safety Concept
2-22
.
Process Control
S7-400 Automation System, CPU Specifications
Manual, 10/2006, 6ES7498-8AA04-8BA0