The S7-400 has two different communication interfaces:

• The cost-effective solution provided by the MPI integrated in the CPU
• The high-performance solution provided by communication modules for point-to-point connections and for connection to PROFIBUS and Industrial Ethernet bus systems.

The following communications modules are available:

• CP 440, CP 441-1 and CP 441-2 for point-to-point connections
• CP 443-5 for connection to PROFIBUS
• CP 443-1 for connection to Industrial Ethernet
• CP 444 for connection to Industrial Ethernet using MMS services in accordance with MAP 3.0