Fault tolerance – Redundant configurations with SIMATIC

As the degree of automation increases in industrial plants, the availability of the implemented systems becomes more and more important. Automation system faults or disturbances result in unproductive and therefore expensive downtimes on the one hand and high restart costs on the other.
Thanks to their redundant structure, high-availability automation systems can ensure that the production process continues even after a fault has occurred.

In this case, changeover from the master system to the standby station is completed within the so-called changeover time. The requirements of "warm standby" (longer changeover time) and "hot standby" (short changeover time) are differentiated according to the length of this changeover time.

Warm-Standby with S7 Software Redundancy

SIMATIC S7 Software Redundancy is a program package containing function blocks for SIMATIC S7 which, in the event of a fault, change over from the master system to the standby system - thus establishing a cost-optimized redundancy solution.  more

Hot-Standby with SIMATIC S7-400H

The SIMATIC S7-400H is a controller with two H CPUs of the same type; in the event of a fault, changeover takes place from the master system to the standby station. It is suitable for high-availability processes with hot standby requirements (processes with changeover times shorter than 100 ms).  more

Flexible Modular Redundancy with SIMATIC S7-400 FH Systems

The SIMATIC S7-400FH system features a unique design that is flexible, modular and redundant and which enables the assembly of extremely fault-tolerant architectures. Unlike traditional leg-based architectures, where the failure of a single component causes shutdown of an entire leg of the system, the SIMATIC S7-400 FH system integrates certified safety-fieldbus technology, allowing each module to function independently of the other modules in the system.  more