Fail-Safe Systems
A5E00085588-03
Glossary-1
Glossary
1oo1 evaluation
Type of sensor evaluation: In 1oo1 evaluation, there is one sensor and it
is connected to the module via a single channel.
1oo2 evaluation
Type of sensor evaluation - In 1oo2 evaluation, the signal states of the
inputs are compared internally (equivalence or non-equivalence).
A
Acceptable risk
The acceptable risk is the highest acceptable risk of a certain technical
procedure or state.
AK requirement classes
Requirement classes (AK) in accordance with DIN V 19250 (DIN V VDE
0801)
Categories or levels describing safety requirements in order to avoid and
deal with faults. The fail-safe signal modules can be used in safety mode
up to requirement class AK6.
C
Channel fault
Channel-related fault (e.g. wire break or short circuit). In channel-specific
passivation, the relevant channel is automatically depassivated after the
problem is eliminated.
Cyclic redundancy check
(CRC)
A test procedure to check the integrity of data. By means of a generator
polynominal, a check sum is formed that is characteristic for the relevant
data volume in the sense of being a signature. A CRC check sum is
formed, for example, for the process values contained in the safety frame
or for the safety-related parameters of the fail-safe signal modules.
D
Dark period
Dark periods occur during switch-off tests and complete bit pattern tests.
This involves test-related 0 signals being switched to the output by the
fail-safe output module while the output is active. The output is then
switched off briefly (dark period). A sufficiently slow actuator does not
respond to this and remains switched on.
Diagnostic coverage level
Percentage of hardware faults that are detected by automatic diagnostic
tests.
Diagnostic test interval (DTI)
Interval between online tests that detect faults in a fail-safe system with a
specific diagnostic coverage level.
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Страница 38: ...Product Overview Fail Safe Systems 1 22 A5E00085588 03 ...
Страница 56: ...Getting Started Fail Safe Systems 2 18 A5E00085588 03 ...
Страница 70: ...Safety Mechanisms Fail Safe Systems 3 14 A5E00085588 03 ...
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Страница 166: ...Operation and Maintenance Fail Safe Systems 6 6 A5E00085588 03 ...
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Страница 344: ...References Fail Safe Systems B 2 A5E00085558 03 ...
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