Allen-Bradley 1794 - Page 13

Publication 1794-RM001G-EN-P - December 2011
SIL Policy 1-9
1794-OB8EP Protected Output Module
2,389,669
(2)
4.18E-07 7.54E-06
1794-OE4 Analog Output Module 23,807,086 4.20E-08 7.41E-07
1794-OF4I Isolated Analog Output Module 7,191,128 1.39E-07 2.47E-06
1794-OW8 Relay Output Module 14,766,876 6.77E-08 1.20E-06
1794-TB3 Terminal Base Units
21,128,346
(2)
4.73E-08 8.35E-07
1794-TB3G Generic Terminal Base Units 27,320,800 3.66E-08 6.45E-07
1794-TB3GS Generic Terminal Base Units 46,425,600 2.15E-08 3.79E-07
1794-TB3S Terminal Base Unit
71,433,747
(2)
1.40E-08 2.46E-07
1794-TB3T Temperature Terminal Base Units
73,096,226
(2)
1.37E-08 2.41E-07
1794-TB3TS Temperature Terminal Base Units
75,763,399
(2)
1.32E-08 2.32E-07
1794-TBN Terminal Base Units 75,716,615 1.32E-08 2.32E-07
1794-TBNF Fused Terminal Base Units
4,812,320
(2)
2.08E-07 3.70E-06
1794-ACNR15XT ControlNet Redundant Media Adapter 8,223,684 1.22E-07 2.15E-06
1794-AENTRXT 10/100Mb Ethernet Redundant Communication Adapter 1,268,070 7.89E-07 1.45E-05
1794-OB8EPXT 8 Protected Output Module 14,771,049 6.77E-08 1.20E-06
1794-IB16XT 16 Sink Input Module 35,587,189 2.81E-08 4.95E-07
1794-OB16PXT 16 Protected Output Module 26,709,401 3.74E-08 6.60E-07
1794-IB10XOB6XT 10 Input/6 Output Combo Module 22,202,487 4.50E-08 7.94E-07
1794-OW8XT 8 Relay Output Module 18,518,519 5.40E-08 9.53E-07
1794-IE4XOE2XT 4 Input/2 Output Analog Combo Module 11,800,802 8.47E-08 1.50E-06
1794-IE8XT 8 Input analog Module 14,041,000 7.12E-08 1.26E-06
1794-OE4XT 4 Output Analog Module 11,381,744 8.79E-08 1.55E-06
1794-IF2XOF2IXT 2 Input/2 Output Isolated Analog Combo Module 6,317,918 1.58E-07 2.81E-06
1794-IF4IXT 4 Isolated Input Analog Module 7,297,140 1.37E-07 2.43E-06
1794-IF4ICFXT 4 Isolated Input Analog Module 7,297,140 1.37E-07 2.43E-06
1794-OF4IXT 4 Isolated Output Analog Module 5,493,902 1.82E-07 3.24E-06
1794-IJ2XT 2 Ch. Frequency Counter Module 11,714,128 8.54E-08 1.51E-06
1794-IRT8XT 8 TC/RTD Input Analog Module 8,204,792 1.22E-07 2.16E-06
(1)
MTBF measured in hours.
(2)
Calculated using field-based values for components
(3)
λ = Failure Rate = 1/MTBF
Table 1.2 FLEX I/O Product Probability of Failure on Demand (PFD) Calculations (T
1
= 1
yr
)
Catalog Number Description Mean Time
Between Failure
(MTBF)
(1)
λ
(3)
Calculated PFD
1oo2 architecture
AB Drives