The S7-400 features two different communication interfaces:

• The cost-effective solution via the MPI interface integrated in the CPU.
• The powerful solution via communication modules for point-to-point connections and for connection to the 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.