Pepperl+Fuchs K-LB Series Manual page 15

Functional Safety K-LB-*.*, F*-LB-I, P-LB-*.*.*
Planning
Field Mount Modules
FN-LB-I, FS-LB-I, FP-LB-I (1oo1 structure)
Parameters Characteristics
Assessment type FMEDA report
and documentation
Device type A
Mode of operation Low demand mode or high demand mode
1
Safety function Pass through the signal
HFT 0
2
SIL 2 or 3
1
Signal type AI
1
Safe state I
in
Signal line
interrupted
Safety loop fault < 3.6 mA and
3
detection > 21 mA can be
detected
+  0 FIT

sd su
6.95 FIT

dd
0 FIT

du
20.1 FIT

no effect
10.1 FIT

not part
6.95 FIT

total (safety function)
4
MTBF 3085 years (all components of the device)
PFH 0.5 x 10
PFD for T = 1 2.19 x 10
avg 1
year
Table 3.4
1
The safe state of the surge protection barrier depend on the application.
2
The maximum safety integrity level of the safety loop in which the device might be used depends on the characteristics
of the whole saftey loop and the connected field devices in the application.
3
This fault detection has to be provided by the safety loop architecture
(e. g. NAMUR signal – lead breakage and short circuit detection, current loop > 20 mA).
4
acc. to SN29500. This characteristic includes failures which are not part of the safety function/MTTR = 8 h.
AO
< 3.6 mA I < 3.6 mA
out
Signal line
interrupted
No fault detection
since < 3.6 mA is
safe state of the
safety loop
6.95 FIT
0 FIT
0 FIT
20.1 FIT
10.1 FIT
6.95 FIT
-8
1/h 0.5 x 10
-5
2.19 x 10
DI
I = 0 mA
out
U = 0 V
out
Signal line
interrupted
SC and LB detection
of the safety loop
0 FIT
6.95 FIT
0 FIT
20.1 FIT
10.1 FIT
6.95 FIT
-8 -8
1/h 0.5 x 10 1/h
-5 -5
2.19 x 10
DO
I = 0 mA
out
U = 0 V
out
Signal line
interrupted
No fault detection
6.95 FIT
0 FIT
0 FIT
20.1 FIT
10.1 FIT
6.95 FIT
-8
0.25 x 10 1/h
-5
1.09 x 10
15