Iso 13849-1:2006 (Previously En 954-1) - Siemens SINAMICS S120 Function Manual

1.2.4 EN ISO 13849-1:2006 (previously EN 954-1)
A qualitative analysis (to EN 954-1) is not sufficient for modern controllers due to their
technology. Among other things, EN 954-1 does not take into account time behavior (e.g.
test interval and/or cyclic test, lifetime). This led to the probability-based approach of EN ISO
13849-1:2006 (probability of failure per time unit).
EN ISO 13849-1:2006 is based on the familiar categories used in EN 954-1. It now also
takes into account complete safety functions and all the devices required to execute these.
In addition to the qualitative approach of EN 954-1, EN ISO 13849-1:2006 now includes a
quantitative analysis of the safety functions. Performance levels (PL), which are based on
the categories, are used. The following safety-related characteristic quantities are required
for devices/equipment:
● Category (structural requirement)
● PL: Performance level
● MTTF
● 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 13849-1:2006 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
Since May 2007, EN ISO 13849-1:2006 has been harmonized as part of the Machinery
Directive. EN 954-1 will still apply until November 30, 2009.
Safety Integrated
Function Manual, (FHS), 11/2009, 6SL3097-4AR00-0BP0
: Mean time to dangerous failure
d
Standards and regulations
1.2 Safety of machinery in Europe
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