Characteristic values of redundant automation systems
A.2 Comparison of MTBF for selected configurations
CPU 410-5H Process Automation
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System Manual, 09/2014, A5E31622160-AB
A.2
Comparison of MTBF for selected configurations
The following sections compare systems with a centralized and distributed I/Os.
The following framework conditions are set for the calculation.
●
MDT (Mean Down Time) 4 hours
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Ambient temperature 40 degrees
●
Buffer voltage is safeguarded
A.2.1
System configurations with redundant CPU 410-5H
The following system with one CPU (e.g., CPU 410-5H PN/DP) in stand-alone operation
serves as the basis for calculating a reference factor that defines the multiple of the system
MTBF of other systems with centralized I/O compared with the base line.
Fault-tolerant CPU in stand-alone operation
Fault-tolerant CPU 410-5H in stand-alone mode
Factor
1