Pepperl+Fuchs VAA-2E-KE1-S, Оригинальное руководство пользователя

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VAA-2E-KE1-S
Annex A
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7.4 Category 4
The occurrence of a fault and an accumulation of faults must not lead to the loss of the safety
function.
Example 1:
Connection of a dual-channel mechanical position switch.
To detect a dangerous accumulation of faults, the safety function must be tested. The test inter-
vals must be adapted to the application.
Figure 7.5
Example 2:
If a dangerous failure (short circuit) of the switch cannot be excluded, two dependent mechani-
cal switches must be used for each channel. To detect a dangerous accumulation of faults, the
safety function must be tested. The test intervals must be adapted to the application.
Figure 7.6
The following function blocks can be parameterized to achieve safety category 4 in this applica-
tion during operation of the AS-Interface safety module on a safety monitor (e.g., VAS-1A-K12
or VAS-2A-K12):
Danger!
The function block "Dual-channel, independent" must not be used in example 3.
Safety circuit
Module
S+1
S-1
S+2
S-2
S+1
S-1
S+2
S-2
Safety circuit
Module
separately
laid
separately
laid