Functional safety in machinery - IEC 62061

Functional safety in machinery - IEC 62061

Summary of the standard




1 Scope

2 Normative references

3 Terms, definitions and abbreviations  

3.1 Alphabetical list of definitions  

3.2 Terms and definitions

3.3 Abbreviations

4 Management of functional safety

4.1 Objective

4.2 Requirements  

5 Requirements for the specification of Safety-Related Control Functions (SRCFs)

5.1 Objective

5.2 Specification of requirements for SRCFs

6 Design and integration of the safety-related electrical control system (SRECS)  

6.1 Objective

6.2 General requirements  

6.3 Requirements for behaviour (of the SRECS) on detection of a fault in the SRECS  

6.4 Requirements for systematic safety integrity of the SRECS

6.5 Selection of safety-related electrical control system  

6.6 Safety-related electrical control system (SRECS) design and development

6.7 Realisation of subsystems

6.8 Realisation of diagnostic functions  

6.9 Hardware implementation of the SRECS

6.10 Software safety requirements specification  

6.11 Software design and development

6.12 Safety-related electrical control system integration and testing  

6.13 SRECS installation  

7 Information for use of the SRECS

7.1 Objective

7.2 Documentation for installation, use and maintenance  

8 Validation of the safety-related electrical control system

8.1 Objective

8.2 General requirements  

8.3 Validation of SRECS systematic safety integrity  

9 Modification  

9.1 Objective

9.2 Modification procedure  

9.3 Configuration management procedures

10 Documentation

Annex A (informative) SIL assignment

Annex B (informative) Example of safety-related electrical control system (SRECS)

design using concepts and requirements of Clauses 5 and 6

Annex C (informative) Guide to embedded software design and development  

Annex D (informative) Failure modes of electrical/electronic components

Annex E (informative) Electromagnetic (EM) phenomenon and increased immunity levels for SRECS intended for use in an industrial environment according to IEC 61000-6-2

Annex F (informative) Methodology for the estimation of susceptibility to common cause failures (CCF)

Figure 1 – Relationship of IEC 62061 to other relevant standards

Figure 2 – Workflow of the SRECS design and development process

Figure 3 – Allocation of safety requirements of the function blocks to subsystems (see  

Figure 4 – Workflow for subsystem design and development (see box 6B of Figure 2)  

Figure 5 – Decomposition of a function block into redundant function block elements and their associated subsystem elements

Figure 6 – Subsystem A logical representation

Figure 7 – Subsystem B logical representation

Figure 8 – Subsystem C logical representation

Figure 9 – Subsystem D logical representation

Figure A.1 – Workflow of SIL assignment process

Figure A.2 – Parameters used in risk estimation

Figure A.3 – Example proforma for SIL assignment process

Figure B.1 – Terminology used in functional decomposition  

Figure B.2 – Example machine

Figure B.3 – Specification of requirements for an SRCF

Figure B.4 – Decomposition to a structure of function blocks  

Figure B.5 – Initial concept of an architecture for a SRECS  

Figure B.6 – SRECS architecture with diagnostic functions embedded within each subsystem (SS1 to SS4)

Figure B.7 – SRECS architecture with diagnostic functions embedded within subsystem SS3

Figure B.8 – Estimation of PFHD for a SRECS

Table 1 – Recommended application of IEC 62061 and ISO 13849-1(under revision) .

Table 2 – Overview and objectives of IEC 62061  

Table 3 – Safety integrity levels: target failure values for SRCFs  

Table 4 – Characteristics of subsystems 1 and 2 used in this example (see Note above)  

Table 5 – Architectural constraints on subsystems: maximum SIL that can be claimed for a SRCF using this subsystem  

Table 6 – Architectural constraints: SILCL relating to categories

Table 7 – Probability of dangerous failure

Table 8 – Information and documentation of a SRECS  

Table A.1 – Severity (Se) classification

Table A.2– Frequency and duration of exposure (Fr) classification

Table A.3– Probability (Pr) classification

Table A.4– Probability of avoiding or limiting harm (Av) classification

Table A.5– Parameters used to determine class of probability of harm (Cl)

Table A.6 – SIL assignment matrix  

Table D.1 – Examples of the failure mode ratios for electrical/electronic components .

Table E.1 – EM phenomenon and increased immunity levels for SRECS

Table E.2 – Selected frequencies for RF field tests

Table E.3 – Selected frequencies for conducted RF tests

Table F.1 – Criteria for estimation of CCF

Table F.2 – Estimation of CCF factor (β