Siemens SIMATIC PCS 7 CPU 410-5H System Manual page 329

Redundant CPUs in different racks
Redundant CPU 410-5H in divided rack, CCF = 2%
Redundant CPU 410-5H in two separate racks, CCF = 1 %
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB
Characteristic values of redundant automation systems
A.2 Comparison of MTBF for selected configurations
Factor
approx. 20
Factor
approx. 38
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