Pepperl+Fuchs NCN3-F31K2 Series, Manual

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Functional Safety NCN3-F31K2(M)-N*-B*3-S
List of Abbreviations
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19
-1
1
17
7 List of Abbreviations
DC D iagnostic C overage of dangerous faults
FIT F ailure I n T ime in 10
-9
1/h
FMEDA F ailure M ode, E ffects, and D iagnostics A nalysis

s
Probability of safe failure

dd
Probability of dangerous detected failure

du
Probability of dangerous undetected failure

no effect
Probability of failures of components in the safety loop that have
no effect on the safety function.

not part
Probability of failure of components that are not in the safety loop

total (safety function)
Probability of failure of components that are in the safety loop
HFT H ardware F ault T olerance
MTBF M ean T ime B etween F ailures
MTTF
D
M ean T ime T o dangerous F ailure
MTTR M ean T ime T o R estoration
OSSD O utput S ignal S witching D evice
PDDB P roximity D evice with D efined B ehaviour under fault conditions
PFD
avg
Average P robability of dangerous F ailure on D emand
PFH Average frequency of dangerous failure per hour
PL P erformance L evel
PLC P rogrammable L ogic C ontroller
PTC P roof T est C overage
s Current operating distance
S
ao
Assured operating distance of a PDDB
S
ar
Assured release distance of a PDDB
s
n
Rated operating distance
SC S ystematic C apability
SFF S afe F ailure F raction
SIL S afety I ntegrity L evel
T
1
Proof Test Interval