EN ISO 13849-1:2015

European foreword
Foreword
Introduction
1 Scope
2 Normative references
3 Terms definitions symbols and abbreviated terms
4 Design considerations
5 Safety functions
6 Categories and their relation to MTTFD of each channel
   DC[avg] and CCF
7 Fault consideration fault exclusion
8 Validation
9 Maintenance
10 Technical documentation
11 Information for use
Annex A (informative) - Determination of required
        performance level (PL[r])
Annex B (informative) - Block method and safety-related
        block diagram
Annex C (informative) - Calculating or evaluating MTTF[D]
        values for single components
Annex D (informative) - Simplified method for estimating
        MTTF[D] for each channel
Annex E (informative) - Estimates for diagnostic coverage
        (DC) for functions and modules
Annex F (informative) - Estimates for common cause
        failure (CCF)
Annex G (informative) - Systematic failure
Annex H (informative) - Example of combination of several
        safety-related parts of the control system
Annex I (informative) - Examples
Annex J (informative) - Software
Annex K (informative) - Numerical representation of Figure 5
Bibliography
Annex ZA (informative) - Relationship between this
         European Standard and the Essential
         Requirements of EU Directive 2006/42/EC

ISO 13849-1:2015 provides safety requirements and guidance on the principles for the design and integration of safety-related parts of control systems (SRP/CS), including the design of software. For these parts of SRP/CS, it specifies characteristics that include the performance level required for carrying out safety functions. It applies to SRP/CS for high demand and continuous mode, regardless of the type of technology and energy used (electrical, hydraulic, pneumatic, mechanical, etc.), for all kinds of machinery.It does not specify the safety functions or performance levels that are to be used in a particular case.This part of ISO 13849 provides specific requirements for SRP/CS using programmable electronic system(s).It does not give specific requirements for the design of products which are parts of SRP/CS. Nevertheless, the principles given, such as categories or performance levels, can be used.NOTE 1 Examples of products which are parts of SRP/CS: relays, solenoid valves, position switches, PLCs, motor control units, two-hand control devices, pressure sensitive equipment. For the design of such products, it is important to refer to the specifically applicable International Standards, e.g. ISO 13851, ISO 13856‑1 and ISO 13856‑2.NOTE 2 For the definition of required performance level, see 3.1.24.NOTE 3 The requirements provided in this part of ISO 13849 for programmable electronic systems are compatible with the methodology for the design and development of safety-related electrical, electronic and programmable electronic control systems for machinery given in IEC 62061.NOTE 4 For safety-related embedded software for components with PLr = e, see IEC 61508?3:1998, Clause 7.