Fault-tolerant automation systems
2.2 Increasing the availability of plants
S7-400H
28
System Manual, 03/2012, A5E00267695-11
Graduated availability by duplicating components
The redundant structure of the S7-400H ensures requirements to reliability at all times. This
means: all essential components are duplicated.
This redundant structure includes the CPU, the power supply, and the hardware for linking
the two CPUs.
You yourself decide on any other components you want to duplicate to increase availability
depending on the specific process you are automating.
Redundancy nodes
Redundant nodes represent the fail safety of systems with redundant components. A
redundant node can be considered as independent when the failure of a component within
the node does not result in reliability constraints in other nodes or in the overall system.
The availability of the overall system can be illustrated simply in a block diagram. With a 1-
out-of-2 system, one component of the redundant node may fail without impairing the
operability of the overall system. The weakest link in the chain of redundant nodes
determines the availability of the overall system
No error/fault
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Figure 2-3
Example of redundancy in a network without error
Содержание SIMATIC S7-400H
Страница 24: ...Preface 1 1 Preface S7 400H 24 System Manual 03 2012 A5E00267695 11 ...
Страница 46: ...Getting Started 4 5 Special layout features of SIMATIC Manager S7 400H 46 System Manual 03 2012 A5E00267695 11 ...
Страница 120: ...Memory concept 10 1 Overview of the memory concept of S7 400H CPUs S7 400H 120 System Manual 03 2012 A5E00267695 11 ...
Страница 258: ...Communication 14 8 General issues regarding communication S7 400H 258 System Manual 03 2012 A5E00267695 11 ...
Страница 354: ...Synchronization modules 18 3 Selecting fiber optic cables S7 400H 354 System Manual 03 2012 A5E00267695 11 ...
Страница 434: ...Technical data 20 6 Runtimes of the FCs and FBs for redundant I Os S7 400H 434 System Manual 03 2012 A5E00267695 11 ...
Страница 460: ...Function modules and communication processors supported by the S7 400H S7 400H 460 System Manual 03 2012 A5E00267695 11 ...