Siemens SIMATIC CPU 410 System Manual page 386

Characteristic values of redundant automation systems
A.2 Comparison of MTBF for selected configurations
Switched distributed I/O, PROFINET, CCF = 2 %
The estimate applies if the process allows for any device to fail.
Redundant CPUs with redundant I/O
The comparison only took account of the I/O modules.
Single-channel one-sided I/O
386
Factor
approx. 10
MTBF factor
1
CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC