System Overview; What Is The S7-1500R/H Redundant System - Siemens Simatic S7-1500R System Manual

System overview

2.1

What is the S7-1500R/H redundant system?

S7-1500R/H redundant system
For the S7-1500R/H redundant system, the CPUs are duplicated, in other words redundant.
The two CPUs process the same project data and the same user program in parallel. The
two CPUs are synchronized over two redundancy connections. If one CPU fails, the other
CPU maintains control of the process.
Aims of using redundant automation systems
Redundant automation systems are used in practice to achieve greater availability or fail-
safety.
● Purpose of fault-tolerant systems: to reduce the probability of production downtime by
operating two systems in parallel.
● Purpose of fail-safe systems: to protect life, the environment and capital with safe
shutdown to a secure state.
Please note the difference between fault-tolerant and fail-safe systems.
S7-1500R/H is a fault-tolerant automation system, but not a fail-safe system. The S7-
1500R/H system must not be used to control safety-critical processes.
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WARNING
S7-1500R/H redundant system
System Manual, 10/2018, A5E41814787-AA
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