Siemens Sinumerik 840D sl Function Manual page 22

Regulations and standards
1.2 Safety of machinery in Europe
Safety--related characteristic quantities for subsystem elements (devices):
S λ: Failure rate
S B10 value: for elements that are subject to wear
S T1: Lifetime
For electro--mechanical devices, a manufacturer specifies a failure rate λ referred
to the number of operating cycles. The failure rate per unit time and the lifetime
must be determined using the switching frequency for the particular application.
Parameters for the subsystem, which comprises subsystem elements, that must
be defined during the design phase:
S T2: Diagnostic test interval
Susceptibility to common cause failure
S β:
S DC: Diagnostic coverage
The PFH
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individual PFH
The user has the following options when setting up a safety--related control sy-
stem:
S Using devices and subsystems that already comply with EN ISO13849--1 or
EN 61508 and/or EN 62061. The standard provides information specifying how
qualified devices can be integrated when safety functions are implemented.
S Develop own subsystems.
-- Programmable, electronic systems and complex systems: Application of
EN 61508 or EN 61800--5--2.
-- Simple devices and subsystems: Application of EN 62061.
Data on non--electrical systems is not included in EN 62061. The standard provi-
des detailed information on implementing safety--related electrical, electronic, and
programmable electronic control systems. EN ISO 13849--1 must be applied for
non--electric systems.
Note
Details of basic subsystems that have been implemented and integrated are
available as function examples.
Note
IEC 62061 has been ratified as EN 62061 in Europe and harmonized as part of the
Machinery Directive.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) - - 10.2015 Edition
value of the safety--related control system is determined by adding the
values of the subsystems.
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