S5-115U Manual
Reliability, Availability and Safety of Electronic Control Equipment
14.4
Summary
•
In electronic control systems, failures of any kind can occur at any point in the system.
•
Even when the greatest efforts are made to obtain maximum reliability, the probability of
such a failure occurring can never be zero.
•
The following is decisive for the effects of such failures: depending on the job a control
system has to do, active or passive failures may be fatal or non-fatal.
•
When safety requirements are very high, fatal failures must be recognized by taking
additional measures and prevented from affecting other parts of the system.
•
In the case of single-channel systems, the means available to do this are relatively limited.
For this reason, safety-oriented functions should generally be implemented outside the
electronics by interposing conventional components.
•
In order to satisfy safety functions, electronic control systems should be of the multi-channel
(redundant) type.
•
These fundamental considerations are independent of
-
the type of control systems (hard-wired or programmable)
-
the vendor
-
the country of origin (Europe, US, etc.).
EWA 4NEB 811 6130-02b
14-7
Содержание SIMATIC S5-115U
Страница 6: ...EWA 4NEB 811 6130 02b ...
Страница 16: ...EWA 4NEB 811 6130 02b ...
Страница 18: ...EWA 4NEB 811 6130 02b ...
Страница 26: ......
Страница 62: ...EWA 4NEB 811 6130 02b ...
Страница 64: ...EWA 4NEB 811 6130 02b ...
Страница 67: ......
Страница 74: ......
Страница 79: ......
Страница 80: ......
Страница 81: ......
Страница 82: ......
Страница 83: ......
Страница 84: ......
Страница 97: ......
Страница 98: ......
Страница 99: ......
Страница 114: ...EWA 4NEB 811 6130 02b ...
Страница 280: ...EWA 4NEB 811 6130 02b ...
Страница 372: ...EWA 4NEB 811 6130 02b ...
Страница 432: ...EWA 4NEB 811 6130 02b ...
Страница 442: ......
Страница 528: ...EWA 4NEB 811 6130 02b ...
Страница 590: ......
Страница 591: ......
Страница 592: ......
Страница 593: ......
Страница 594: ......
Страница 600: ...EWA 4NEB 811 6130 02b ...
Страница 602: ...EWA 4NEB 811 6130 02b ...
Страница 604: ...EWA 4NEB 811 6130 02b ...
Страница 624: ...EWA 4NEB 811 6130 02b ...
Страница 632: ...EWA 4NEB 811 6130 02b ...
Страница 644: ...EWA 4NEB 811 6130 02b ...
Страница 646: ...EWA 4NEB 811 6130 02b ...
Страница 652: ...EWA 4NEB 811 6130 02b ...
Страница 654: ...EWA 4NEB 811 6130 02b ...
Страница 660: ...EWA 4NEB 811 6130 02b ...
Страница 662: ...EWA 4NEB 811 6130 02b ...
Страница 666: ...EWA 4NEB 811 6130 02b ...
Страница 668: ...EWA 4NEB 811 6130 02b ...
Страница 674: ...EWA 4NEB 811 6130 02b ...