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Rockwell Automation Publication 1756-UM013B-EN-P - October 2019
Appendix D
Safety Data for Safety Modules
1756-IB16S Safety Data
lists the safety data for the 1756-IB16S module.
Table 8 - 1756-IB16S Module Safety Parameter Data
Attribute
Point Operation Type
Single Channel
Dual Channel
(at controller instruction
level)
Safety Function Architecture (HFT)
0
1
Safe Failure Rate (
λ
s
) [failures/hr]
7.9621E-07
8.6252E-07
Safe Detected Failure Rate (
λ
SD
)
(1)
7.95153E-07
8.61767E-07
Safe Undetected Failure Rate (
λ
SU
)
1.05746E-09
7.52962E-10
Dangerous Failure Rate (
λ
D
) [failures/hr]
4.49496E-07
5.34022E-07
Dangerous Detected Failure Rate (
λ
DD
) [failures/hr]
4.48899E-07
5.33556E-07
Dangerous Undetected Failure Rate (
λ
DU
) [failures/hr]
3.80996E-10
4.6619E-10
SRT [millisecond]
6
Automatic Diagnostic Test Interval (TD) [hr]
4
Useful Life [yr]
20
Systematic Capability (SC)
3
Safe Failure Fraction (SFF) [%]
99.97%
99.97%
PFH
3.80996E-10
4.6619E-10
PFD
AVE
10 yrs
1.66876E-05
2.04191E-05
Mission Time™
20 yrs
3.33753E-05
4.08383E-05
Diagnostic Coverage Average (DC
AVE
)
99.87%
99.91%
Spurious Trip Rate (STR)
5.90E-06
—
MTTF [years]
91.64
81.74
MTTF
D
[years]
253.96
213.76
(1) (
λ
SD) and (
λ
SU) are calculated with assumption of Diagnostic Coverage of Safe Failure is same as Diagnostic Coverage of Dangerous Failure
Summary of Contents for 1756 Series
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