Appendix
36
Hans Turck GmbH & Co. KG | T +49 208 4952-0 | F +49 208 4952-264 | [email protected] | www.turck.com
10
Appendix: designations and abbreviations
Abbreviation Meaning
DC
Diagnostic Coverage
HFT
Hardware failure tolerance
MTTF
D
Mean Time To Failure Dangerous
PFD
Probability of dangerous failure on demand
PFH
D
Average frequency of dangerous failure per hour
PL
Performance Level
SIL
Safety Integrity Level
11
Appendix: function tests
Ensure that the function test is only carried out by qualified personnel. A suggested function
test consists of the following steps:
Step
Action
1
Switch every safety related input at least once a year.
2
Control the switching behavior by monitoring the output circuits.
3
Observe the maximum duty cycle and the total operation time depending on
the selected PFD value.
4
If the maximum duty cycle is reached: Request the shutdown function in order
to check the function of the safety system.
Once the test has been completed, document and archive the results.
12
Appendix: document history
Version
Date
Modifications
1.0
07/01/2020
First version
2.0
07/15/2022
Chapter "For your safety" added
Chapter "Obvious misuse” supplemented and renamed to
"Reasonably foreseeable misuse" supplemented
Use in Zone 2 added
LL device variants added
Safety characteristic data updated
Chapter "Addressing" supplemented
”Appendix: directives and standards” added
”Appendix: approvals and markings” added
Technical data supplemented