Siemens SINUMERIK MC Commissioning Manual page 345

Preventive maintenance (proof test)
The probability values for the certified F-system components guarantee a proof-test interval of
20 years for ordinary configurations.
Proof test for complex electronic components generally means replacement with unused
components.
PFD, PFH values for F-CPU S7-1500
Probability of failure values (PFD
years and for a repair time of 100 hours are subsequently listed:
Low demand mode of operation
low demand mode
According to IEC 61508:2010:
PFD = Average probability of a dangerous failure on de‐
avg
mand
< 2E-05
PFD, PFH values for safety-related communication
Below you will find the failure probability values (PFD
communication:
Low demand mode of operation
low demand mode
According to IEC 61508:2010:
PFD = Average probability of a dangerous failure on de‐
avg
mand
< 1E-05
Safety Integrated (with SINAMICS S120)
Commissioning Manual, 02/2020, A5E46305916B AB
Component replacement (software/hardware)
-, PFH values) for F-CPU S7-1500 for a usage time of 20
avg
High demand or continuous mode of operation
high demand/continuous mode
According to IEC 61508:2010:
PFH = Average frequency of a dangerous failure [h
< 1E-09
, PFH values) for safety-related
avg
High demand or continuous mode of operation
high demand/continuous mode
According to IEC 61508:2010:
PFH = Average frequency of a dangerous failure [h
< 1E-09
9.2 Software, F-CPU, F-I/O
]
-1
]
-1
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