The S7-400 is the most powerful PLC in the family of SIMATIC controllers. It enables successful automation solutions with Totally Integrated Automation (TIA). The S7-400 is an automation platform for system solutions in production and process engineering, and it is characterized primarily by its modularity and performance reserves.

• The power PLC for the mid to high-end performance ranges
• The solution for even the most demanding tasks
• With a comprehensive range of modules and performance-graded CPUs for optimal adaptation to the automation task
• Flexible in use through simple implementation of distributed structures
• User-friendly connections
• Optimal communication and networking options
• User-friendly handling and uncomplicated design without a fan
• Can be expanded without problems when the tasks increase
• Multicomputing:
Simultaneous operation of several CPUs in one S7-400 central controller.
Multicomputing distributes the overall performance of an S7-400. For example, complex tasks in technologies such as open-loop control, computing or communication can be split and assigned to different CPUs. And every CPU can be assigned its own local I/O.
• Modularity:
The powerful backplane bus of the S7-400 and the communication interfaces that can be connected direct to the CPU enable high-performance operation of a host of communication lines. This permits, for example, the division into one communications line for HMI and programming tasks, one line for high-performance and equidistant motion control components, and one “normal” I/O fieldbus. Additionally required connections to MES/ERP systems or the Internet can also be implemented.
• Engineering and diagnostics:
The S7-400 is configured and programmed extremely efficiently together with the SIMATIC Engineering Tools particularly in the case of extensive automation solutions with a high engineering component. For this purpose, high-level languages such as SCL and graphical engineering tools for sequential controls, state graphs and technology-oriented diagrams are available, for example.

Application of S7-400
The modular and fan-free design, high level of expandability, extensive communication and networking options, simple implementation of distributed structures, and user-friendly handling make the SIMATIC S7-400 the ideal solution even for the most demanding tasks in the mid to high-end performance ranges.
Application areas of the SIMATIC S7-400 include:
• Automotive industry, e.g. assembly lines
• Mechanical equipment manufacture, including special mechanical equipment manufacture
• Warehousing technology
• Steel industry
• Building management systems
• Power generation and distribution
• Paper and printing industry
• Woodworking
• Food and beverages industry
• Process engineering, e.g. water and wastewater utilities
• Chemicals industry and petrochemicals
• Instrumentation and control
• Packaging machinery
• Pharmaceutical industry
Several performance-graded CPU classes and a comprehensive range of modules with a host of user-friendly functions allow users to perform their automation tasks individually.
In the case of task expansions, the controller can be expanded at any time without significant cost by means of additional modules.
The SIMATIC S7-400 is universal in use:
• Maximum suitability for industry thanks to high electromagnetic compatibility and high resistance to shock and vibration.
• Modules can be connected and disconnected while power switched on.



• High-availability automation system with redundant design
• For applications with high fail-safety requirements:
Processes with high restart costs, expensive downtimes, little supervision, and few maintenance options
• Redundantly designed central functions
• Increases availability of I/O: switched I/O configuration
• Also possible to use I/Os with standard availability: single-sided configuration
• Hot stand-by: Automatic reaction-free switching to the standby unit in the event of a fault
• Configuration with 2 separate or one divided central rack
• Connection of switched I/O via redundant PROFIBUS DP or system-redundant PROFINET I/O.

Application of S7-400H
In many areas of automation technology, demands are increasing all the time with regard to the availability and thus the fail-safety of the automation systems. There are areas where a plant standstill can result in extremely high costs. Here, only redundant systems can do justice to the availability requirements.
The fault-tolerant SIMATIC S7-400H meets these requirements. It continues to operate even when parts of the controller have failed due to one or more faults. The availability achieved in this way makes the SIMATIC S7-400H especially suitable for the following application areas:
• Processes with high restart costs after a controller failure (generally in the process industry).
• Processes with expensive standstill times
• Processes involving valuable materials, e.g. in the pharmaceuticals industry.
• Unsupervised applications
• Applications with reduced maintenance personnel



• Failsafe automation system for plants with increased safety requirementss7 400 FH
• Complies with safety requirements to SIL 3 in accordance with IEC 61508, AK6 in accordance with DIN V 19250 and Cat. 4 in accordance with EN 954-1
• If required, also fault tolerant through redundant design
• Without additional wiring of the safety-related I/O
• Safety-relevant communication via PROFIBUS DP with PROFIsafe profile
• Based on S7-400H and distributed ET 200 I/O with fail-safe modules
• Standard modules for non-safety-related applications can also be used in the automation system
• Isolation module for the combined use of fail-safe and standard modules in safety mode in one ET 200M.


Application of S7-400F/FH
The SIMATIC S7-400F/FH fail-safe automation system is used in plants with increased safety requirements. It controls processes where immediate shutdown presents no danger to personnel or the environment. The S7-400F/FH has two basic designs:
• S7-400F:
Fail-safe automation system. In the event of faults in the control system, the production process is brought to a safe state and interrupted.
• S7-400FH:
Fail-safe and high-availability automation system. In the event of a fault in the control system, redundant control sections intervene and continue control of the production process.
The additional use of standard modules makes it possible to establish a fully integrated control system for a plant where non-safety related tasks and safety-related tasks co-exist. The overall plant is configured and programmed with the same standard tools