Rockwell Automation Publication 1734-UM013N-EN-P - September 2017 209
Safety Data Appendix D
Product Failure Rates
(failures per hour)
All 1734-IB8S safety input channels, all 1734-OB8S safety output channels, and
all 1734-OBV2S safety output channels must utilize pulse testing when used in
single channel functional safety applications
Table 21 - Product Failure Rates (failures per hour)
(1)
(1) These failure rates assume that the module is represented by one block in a reliability block diagram. The single channel rates must
be applied to the reliability block if the module is configured in Single Channel mode. The dual channel rates must be applied to the
reliability block if the module is configured in Dual Channel mode.
Catalog Number Series Module I/O
Configuration
λ
S
λ
DD
λ
DU
1734-IB8S B Single Channel Inputs 2.56E-07 2.55E-07 6.02E-10
1734-OB8S B Single Channel Outputs
(2)
(2) 1734-OB8S single channel mode is only certified for functional safety applications with Process Safety Times ≥ 600 msec or with
Demand Rates ≤ 1 Demand per Minute.
2.52E-07
(2)
2.52E-07
(2)
4.47E-09
(2)
1734-IE4S A Single Channel Inputs 4.23E-07 4.23E-07 1.01E-10
1734-IB8S B Dual Channel Inputs 2.96E-07 2.94E-07 1.84E-10
1734-OB8S B Dual Channel Outputs 2.95E-07 2.95E-07 1.84E-10
1734-OBV2S B Dual Channel Outputs 4.08E-07 4.08E-07 2.41E-10
1734-IE4S A Dual Channel Inputs 6.56E-07 6.56E-07 6.67E-11