IEC 61131-6:2012

IEC 61131-6 ®
Edition 1.0 2012-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Programmable controllers –
Part 6: Functional safety
Automates programmables –
Partie 6: Sécurité fonctionnelle

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IEC 61131-6 ®
Edition 1.0 2012-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Programmable controllers –
Part 6: Functional safety
Automates programmables –
Partie 6: Sécurité fonctionnelle

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XD
ICS 25.040.40; 35.240.50 ISBN 978-2-83220-402-3

– 2 – 61131-6 © IEC:2012
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 10
2 Normative references . 11
3 Terms and definitions . 12
4 Conformance to this standard . 25
5 FS-PLC safety lifecycle . 25
5.1 General . 25
5.2 FS-PLC functional safety SIL capability requirements . 27
5.2.1 General . 27
5.2.2 Data security . 28
5.3 Quality management system . 28
5.4 Management of FS-PLC safety lifecycle . 29
5.4.1 Objectives . 29
5.4.2 Requirements and procedures . 29
5.4.3 Execution and monitoring . 33
5.4.4 Management of functional safety . 33
6 FS-PLC design requirements specification. 33
6.1 General . 33
6.2 Design requirements specification contents . 34
6.3 Target failure rate . 35
7 FS-PLC design, development and validation plan . 36
7.1 General . 36
7.2 Segmenting requirements . 36
8 FS-PLC architecture . 37
8.1 General . 37
8.2 Architectures and subsystems . 38
8.3 Data communication . 38
9 HW design, development and validation planning . 38
9.1 HW general requirements . 38
9.2 HW functional safety requirements specification . 38
9.3 HW safety validation planning . 38
9.4 HW design and development . 39
9.4.1 General . 39
9.4.2 Requirements for FS-PLC behaviour on detection of a fault . 39
9.4.3 HW safety integrity . 40
9.4.4 Random HW failures . 48
9.4.5 HW requirements for the avoidance of systematic failures . 53
9.4.6 HW requirements for the control of systematic faults . 53
9.4.7 HW classification of faults . 54
9.4.8 HW implementation . 55
9.4.9 De-rating of components. 56
9.4.10 ASIC design and development . 56
9.4.11 Techniques and measures to prevent the introduction of faults in
ASICs . 56

61131-6 © IEC:2012 – 3 –
9.5 HW and embedded SW and FS-PLC integration . 56
9.6 HW operation and maintenance procedures . 57
9.6.1 Objective . 57
9.6.2 Requirements . 57
9.7 HW safety validation . 58
9.7.1 General . 58
9.7.2 Requirements . 58
9.8 HW verification . 59
9.8.1 Objective . 59
9.8.2 Requirements . 59
10 FS-PLC SW design and development . 60
10.1 General . 60
10.2 Requirements . 61
10.3 Classification of engineering tools . 61
10.4 SW safety validation planning . 62
11 FS-PLC safety validation . 62
12 FS-PLC type tests . 62
12.1 General . 62
12.2 Type test requirements . 62
12.3 Climatic test requirements . 65
12.4 Mechanical test requirements . 65
12.5 EMC test requirements . 65
12.5.1 General . 65
12.5.2 General EMC environment . 65
12.5.3 Specified EMC environment . 67
13 FS-PLC verification . 69
13.1 Verification plan . 69
13.2 Fault insertion test requirements . 70
13.3 As qualified versus as shipped . 71
14 Functional safety assessment . 71
14.1 Objective . 71
14.2 Assessment requirements . 72
14.2.1 Assessment evidence and documentation . 72
14.2.2 Assessment method . 72
14.3 FS-PLC
...