Siemens SIMATIC CPU 410 System Manual page 385

Redundant CPUs with single-channel one-sided or switched I/O
One-sided distributed I/O
Switched distributed I/O, PROFIBUS DP, CCF = 2 %
CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC
Characteristic values of redundant automation systems
A.2 Comparison of MTBF for selected configurations
Base line
1
Factor
approx. 15
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