Multipoint Interface (Mpi) - Siemens SIMATIC S7-400 Manual

2.9

Multipoint Interface (MPI)

Availability
All the CPUs of the S7-400 feature an MPI interface.
Connectable Devices
You can connect the following stations to the MPI, for example:
● Programming devices (PG/PC)
● Control and monitoring devices (OPs and TDs)
● Additional SIMATIC S7 PLCs
Some devices use the 24 VDC power supply of the interface. This voltage is provided at the
MPI interface connected to a reference potential
Programming Device/OP ->CPU Communication
A CPU is capable of maintaining several simultaneous online connections. Only one of these
connections is reserved as default connection for a programming device, and a second for
the OP/ control and monitoring device.
For CPU-specific information on the number of connection resources of connectable OPs,
refer to the Technical Specifications.
Time synchronization By Using MPI
Time synchronization is possible by using the MPI interface of the CPU. The CPU can be
master or slave.
CPU-CPU Communication
There are three types of CPU-CPU communication:
● Data transfer by means of S7 basic communication
● Data transfer by means of S7 communication
● Data transfer by means of global data communication
For further information, refer to the
Connectors
Always use bus connectors with the oblique cable outlet for PROFIBUS DP or PG cables
used to connect devices to the MPI (see the manual
and Installation
S7-400 Automation System, CPU Specifications
Manual, 10/2006, 6ES7498-8AA04-8BA0
Programming with STEP 7
).
Structure of a CPU 41x
2.9 Multipoint Interface (MPI)
manual.
S7-400 Automation System, Hardware
2-21