The SIMATIC S7-400 Power PLC is a powerful PLC that is suitable for medium to high performance control applications. It has function-graded CPUs and a wide variety of modules, which always provide the best solution for automation tasks. Distributed system and extended communication capabilities are easy to implement, and the system can be flexibly composed. In addition, its user-friendliness is strong, the operation is simple, and the fanless design. With the expansion of applications, system expansion is not a problem.
This manual describes the SIMATIC S7-400 programmable controller, its hardware modules, expansion options, and supported communication interfaces. It covers system architecture, CPU and module types, and the procedures for installing and wiring the controller in a rack.
The document also explains programming concepts, data exchange via MPI, PROFIBUS‑DP, Ethernet, and other fieldbus options, as well as specifications for memory, expansion unit limits, and typical application fields such as industrial automation, building control, and process engineering. This manual is written in Chinese.
| Flash memory (MC 521) | 2 MB |
|---|---|
| RAM | 64 KB |
| Maximum line length for IM 461-3 | 100 m |
| Maximum number of expansion units per central controller | 21 |
A central controller can connect up to 21 expansion units.
The maximum line length for IM 461-3 is 100 m.