Rockwell Automation 1794 FLEX I/O System with ControlLogix for SIL2 User Manual
Page 51
Publication 1794-RM001G-EN-P - December 2011
Failure Estimates A-5
1794-IB10XOB6XT
10 Input/6 Output Combo Module
22,202,487
4.50E-08
4.00E-06
1794-OW8XT
8 Relay Output Module
18,518,519
5.40E-08
4.81E-06
1794-IE4XOE2XT
4 Input/2 Output Analog Combo Module
11,800,802
8.47E-08
7.61E-06
1794-IE8XT
8 Input analog Module
14,041,000
7.12E-08
6.37E-06
1794-OE4XT
4 Output Analog Module
11,381,744
8.79E-08
7.89E-06
1794-IF2XOF2IXT
2 Input/2 Output Isolated Analog Combo Module
6,317,918
1.58E-07
1.45E-05
1794-IF4IXT
4 Isolated Input Analog Module
7,297,140
1.37E-07
1.25E-05
1794-IF4ICFXT
4 Isolated Input Analog Module
7,297,140
1.37E-07
1.25E-05
1794-OF4IXT
4 Isolated Output Analog Module
5,493,902
1.82E-07
1.68E-05
1794-IJ2XT
2 Ch. Frequency Counter Module
11,714,128
8.54E-08
7.67E-06
1794-IRT8XT
8 TC/RTD Input Analog Module
8,204,792
1.22E-07
1.11E-05
(1)
MTBF measured in hours.
(2)
Calculated using field-based values for components
(3)
λ
= Failure Rate = 1 / MTBF
Table A.3 MTBF Field Data and Per Module PFD Estimates - T
1
= 5 years
Catalog Number:
Description:
(MTBF)
(1)
λ
(3)
Estimated
PFD 1oo2
Table A.4 MTBF Field Data and Per Module PFH Estimates - T
1
= 1 year
Catalog Number:
Description:
(MTBF)
(1)
λ
(3)
Estimated
PFH 1oo2
1794-ACN15
ControlNet Single Media Adapter
8,223,684
1.22E-07
8.64E-10
1794-ACNR15
ControlNet Redundant Media Adapter
8,223,684
1.22E-07
8.64E-10
1794-AENT
10/100Mb Ethernet Communication Adapter
691,134
1.45E-06
1.19E-08
1794-AENTR
10/100Mb Ethernet Redundant Communication Adapter
1,268,070
(2)
7.89E-07
6.05E-09
1794-IB10XOB6
10 Input/6 Output Module
4,943,442
2.02E-07
1.45E09
1794-IB16
16 Sink Input Module
4,105,090
2.44E-07
1.76E-09
1794-IE8
Analog Input Module
37,952,679
2.63E-08
1.85E-10
1794-IF2XOF2I
Isolated Analog Input/Output Module
25,296,960
3.95E-08
2.78E-10
1794-IF4I
Isolated Analog Input Module
11,746,343
8.51E-08
6.02E-10
1794-IJ2
Frequency Counter Module
2,418,321
4.14E-07
3.04E09
1794-IP4
Pulse Counter Module
2,375,360
4.21E-07
3.10E09
1794-IR8
RTD Input Module
6,191,655
1.62E-07
1.15E-09
1794-IRT8
TC/RTD/mV Input Module
1,182,438
8.46E-07
6.53E-09
1794-IT8
Thermocouple Input Module
1,564,324
6.39E-07
4.82E-09
1794-OB16
16 Source Output Module
1,883,594
5.31E-07
3.96E-09
1794-OB16P
Protected Output Module
2,135,280
4.68E-07
3.47E09
1794-OB8EP
Protected Output Module
2,389,669
(2)
4.18E-07
3.08E09