Siemens SIMOTICS S-1FL6, Руководство по эксплуатации

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Safety Integrated function
8.1 Standards and regulations
SINAMICS V90, SIMOTICS S-1FL6
298
Operating Instructions, 04/2019, A5E36037884-007
● MTTF
d
: Mean time to dangerous failure
● DC: Diagnostic coverage
● CCF: Common cause failure
The standard describes how the performance level (PL) is calculated for safety-related
components of the controller on the basis of designated architectures. In the event of any
deviations from this, EN ISO 13849-1 refers to EN 61508.
When combining several safety-related parts to form a complete system, the standard
explains how to determine the resulting PL.
Note
DIN EN ISO 13849-1 and machinery directive
Since May 2007, DIN EN ISO 13849-1 has been harmonized as part of the Machinery
Directive.
8.1.2.5 EN 62061
EN 62061 (identical to IEC 62061) is a sector-specific standard subordinate to IEC/EN
61508. It describes the implementation of safety-related electrical machine control systems
and looks at the complete life cycle, from the conceptual phase to decommissioning. The
standard is based on the quantitative and qualitative analyses of safety functions, whereby it
systematically applies a top-down approach to implementing complex control systems
(known as "functional decomposition"). The safety functions derived from the risk analysis
are sub-divided into sub-safety functions, which are then assigned to real devices, sub-
systems, and sub-system elements. Both the hardware and software are covered. EN 62061
also describes the requirements placed on implementing application programs.
A safety-related control system comprises different sub-systems. From a safety perspective,
the sub-systems are described in terms of the SIL claim limit and PFHD characteristic
quantities.
Programmable electronic devices (e.g. PLCs or variable-speed drives) must fulfill EN 61508.
They can then be integrated in the controller as sub-systems. The following safety-related
characteristic quantities must be specified by the manufacturers of these devices.
Safety-related characteristic quantities for subsystems:
● SIL CL: SIL claim limit
● PFHD: Probability of dangerous failures per hour
● T1: Lifetime
Simple sub-systems (e.g. sensors and actuators) in electromechanical components can, in
turn, comprise sub-system elements (devices) interconnected in different ways with the
characteristic quantities required for determining the relevant PFHD value of the sub-system.
Safety-related characteristic quantities for subsystem elements (devices):
● λ: Failure rate
● B10 value: For elements that are subject to wear
● T1: Lifetime