SIST EN IEC 61784-3-8:2021
(Main)Industrial communication networks - Profiles - Part 3-8: Functional safety fieldbuses - Additional specifications for CPF8 (IEC 61784-3-8:2021)
Industrial communication networks - Profiles - Part 3-8: Functional safety fieldbuses - Additional specifications for CPF8 (IEC 61784-3-8:2021)
IEC 61784-3-8:2021 specifies a safety communication layer (services and protocol) based on CPF 8 of IEC 61784 1, IEC 61784-2 and IEC 61158 Type 18 and Type 23. It identifies the principles for functional safety communications defined in IEC 61784 3 that are relevant for this safety communication layer. This safety communication layer is intended for implementation in safety devices only.
NOTE 1 It does not cover electrical safety and intrinsic safety aspects. Electrical safety relates to hazards such as electrical shock. Intrinsic safety relates to hazards associated with potentially explosive atmospheres.
This document defines mechanisms for the transmission of safety-relevant messages among participants within a distributed network using fieldbus technology in accordance with the requirements of IEC 61508 (all parts) for functional safety. These mechanisms may be used in various industrial applications such as process control, manufacturing automation and machinery. This document provides guidelines for both developers and assessors of compliant devices and systems.
Industrielle Kommunikationsnetze - Profile - Teil 3-8: Funktional sichere Übertragung bei Feldbussen - Zusätzliche Festlegungen für die Kommunikationsprofilfamilie 8 (IEC 61784-3-8:2021)
Réseaux de communication industriels - Profils - Partie 3-8: Bus de terrain de sécurité fonctionnelle - Spécifications supplémentaires pour CPF 8 (IEC 61784-3-8:2021)
L'IEC 61784-3-8:2021 spécifie une couche de communication de sécurité (services et protocole) qui repose sur la CPF 8 de l'IEC 61784 1, de l'IEC 61784-2 et de l'IEC 61158 Type 18 et Type 23. Elle identifie les principes applicables aux communications de sécurité fonctionnelle définies dans l'IEC 61784 3, qui correspondent à cette couche de communication de sécurité. Cette couche de communication de sécurité est destinée à être mise en œuvre uniquement sur les appareils de sécurité.
NOTE 1 Elle ne couvre pas les aspects relatifs à la sécurité électrique et à la sécurité intrinsèque. La sécurité électrique concerne les dangers tels que les chocs électriques. La sécurité intrinsèque concerne les dangers associés aux atmosphères explosibles.
Le présent document définit les mécanismes de transmission des messages relatifs à la sécurité entre les participants d'un réseau réparti, en utilisant la technologie de bus de terrain conformément aux exigences de la série IEC 61508 (toutes les parties) concernant la sécurité fonctionnelle. Ces mécanismes peuvent être utilisés dans différentes applications industrielles, par exemple la commande de processus, l'usinage automatique et les machines. Le présent document fournit des lignes directrices aux développeurs, ainsi qu'aux évaluateurs d'appareils et de systèmes conformes.
Industrijska komunikacijska omrežja - Profili - 3-8. del: Funkcijska varnost procesnih vodil - Dodatne specifikacije za CPF 8 (IEC 61784-3-8:2021)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2021
Nadomešča:
SIST EN 61784-3-8:2018
Industrijska komunikacijska omrežja - Profili - 3-8. del: Funkcijska varnost
procesnih vodil - Dodatne specifikacije za CPF 8 (IEC 61784-3-8:2021)
Industrial communication networks - Profiles - Part 3-8: Functional safety fieldbuses -
Additional specifications for CPF8 (IEC 61784-3-8:2021)
Industrielle Kommunikationsnetze - Profile - Teil 3-8: Funktional sichere Übertragung bei
Feldbussen - Zusätzliche Festlegungen für die Kommunikationsprofilfamilie 8 (IEC
61784-3-8:2021)
Réseaux de communication industriels - Profils - Partie 3-8: Bus de terrain de sécurité
fonctionnelle - Spécifications supplémentaires pour CPF 8 (IEC 61784-3-8:2021)
Ta slovenski standard je istoveten z: EN IEC 61784-3-8:2021
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
35.100.05 Večslojne uporabniške Multilayer applications
rešitve
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 61784-3-8
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2021
ICS 25.040.40; 35.100.05 Supersedes EN 61784-3-8:2017 and all of its
amendments and corrigenda (if any)
English Version
Industrial communication networks - Profiles - Part 3-8:
Functional safety fieldbuses - Additional specifications for CPF8
(IEC 61784-3-8:2021)
Réseaux de communication industriels - Profils - Partie 3-8: Industrielle Kommunikationsnetze - Profile - Teil 3-8:
Bus de terrain de sécurité fonctionnelle - Spécifications Funktional sichere Übertragung bei Feldbussen -
supplémentaires pour CPF 8 Zusätzliche Festlegungen für die
(IEC 61784-3-8:2021) Kommunikationsprofilfamilie 8
(IEC 61784-3-8:2021)
This European Standard was approved by CENELEC on 2021-06-23. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61784-3-8:2021 E
European foreword
The text of document 65C/1083/FDIS, future edition 3 of IEC 61784-3-8, prepared by SC 65C
"Industrial networks" of IEC/TC 65 "Industrial-process measurement, control and automation" was
submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 61784-3-8:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-03-23
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-06-23
document have to be withdrawn
This document supersedes EN 61784-3-8:2017 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 61784-3-8:2021 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 61000-1-2 NOTE Harmonized as EN 61000-1-2
IEC 61000-6-7 NOTE Harmonized as EN 61000-6-7
IEC 61010-2-201 NOTE Harmonized as EN IEC 61010-2-201
IEC 61131-6 NOTE Harmonized as EN 61131-6
IEC 61158-1 NOTE Harmonized as EN IEC 61158-1
IEC 61158-5 (series) NOTE Harmonized as EN 61158-5 (series)
IEC 61496 (series) NOTE Harmonized as EN IEC 61496 (series)
IEC 61508-1:2010 NOTE Harmonized as EN 61508-1:2010 (not modified)
IEC 61508-4:2010 NOTE Harmonized as EN 61508-4:2010 (not modified)
IEC 61508-5:2010 NOTE Harmonized as EN 61508-5:2010 (not modified)
IEC 61784-3 (series) NOTE Harmonized as EN 61784-3 (series)
IEC 61784-5 (series) NOTE Harmonized as EN IEC 61784-5 (series)
IEC 61800-5-2 NOTE Harmonized as EN 61800-5-2
IEC 61918:2018 NOTE Harmonized as EN IEC 61918:2018 (not modified)
IEC 62443 (series) NOTE Harmonized as EN IEC 62443 (series)
ISO 10218-1 NOTE Harmonized as EN ISO 10218-1
ISO 13849 (series) NOTE Harmonized as EN ISO 13849 (series)
ISO 13849-1:2015 NOTE Harmonized as EN ISO 13849-1:2015 (not modified)
ISO 13849-2 NOTE Harmonized as EN ISO 13849-2
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is
available here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 61131-2 - Industrial-process measurement and - -
control - Programmable controllers - Part 2:
Equipment requirements and tests
IEC 61158 series Industrial communication networks - EN IEC 61158 series
Fieldbus specifications
IEC 61158-2 - Industrial communication networks - EN 61158-2 -
Fieldbus specifications - Part 2: Physical
layer specification and service definition
IEC 61158-3-18 - Industrial communication networks - EN 61158-3-18 -
Fieldbus specifications - Part 3-18: Data-
link layer service definition - Type 18
elements
IEC 61158-4-18 - Industrial communication networks - EN 61158-4-18 -
Fieldbus specifications - Part 4-18: Data-
link layer protocol specification - Type 18
elements
IEC 61158-5-18 - Industrial communication networks - EN 61158-5-18 -
Fieldbus specifications - Part 5-18:
Application layer service definition - Type
18 elements
IEC 61158-5-23 - Industrial communication networks - EN IEC 61158-5-23 -
Fieldbus specifications - Part 5-23:
Application layer service definition - Type
23 elements
IEC 61158-6-18 - Industrial communication networks - EN 61158-6-18 -
Fieldbus specifications - Part 6-18:
Application layer protocol specification -
Type 18 elements
IEC 61158-6-23 - Industrial communication networks - EN IEC 61158-6-23 -
Fieldbus specifications - Part 6-23:
Application layer protocol specification -
Type 23 elements
Publication Year Title EN/HD Year
IEC 61326-3-1 - Electrical equipment for measurement, EN 61326-3-1 -
control and laboratory use - EMC
requirements - Part 3-1: Immunity
requirements for safety-related systems
and for equipment intended to perform
safety-related functions (functional safety) -
General industrial applications
IEC 61326-3-2 - Electrical equipment for measurement, EN IEC 61326-3-2 -
control and laboratory use - EMC
requirements - Part 3-2: Immunity
requirements for safety-related systems
and for equipment intended to perform
safety-related functions (functional safety) -
Industrial applications with specified
electromagnetic environment
IEC 61508 series Functional safety of EN 61508 series
electrical/electronic/programmable
electronic safety-related systems
IEC 61511 series Functional safety - Safety instrumented EN 61511 series
systems for the process industry sector -
IEC 61784-1 - Industrial communication networks - EN IEC 61784-1 -
Profiles Part 1: Fieldbus profiles
IEC 61784-2 - Industrial communication networks - EN IEC 61784-2 -
Profiles - Part 2: Additional fieldbus profiles
for real-time networks based on
ISO/IEC/IEEE 8802-3
IEC 61784-3 2021 Industrial communication networks - EN IEC 61784-3 2021
Profiles - Part 3: Functional safety
fieldbuses - General rules and profile
definitions
IEC 62061 - Safety of machinery - Functional safety of EN IEC 62061 -
safety-related control systems
ISO/IEC/IEEE 8802-3 - Information technology - - -
Telecommunications and information
exchange between systems - Local and
metropolitan area networks - Specific
requirements - Part 3: Standard for
Ethernet
IEC 61784-3-8 ®
Edition 3.0 2021-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – Profiles –
Part 3-8: Functional safety fieldbuses – Additional specifications for CPF 8
Réseaux de communication industriels – Profils –
Partie 3-8: Bus de terrain de sécurité fonctionnelle – Spécifications
supplémentaires pour CPF 8
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040.40; 35.100.05 ISBN 978-2-8322-9751-3
– 2 – IEC 61784-3-8:2021 IEC 2021
CONTENTS
FOREWORD . 7
0 Introduction . 9
0.1 General . 9
0.2 Patent declaration . 11
1 Scope . 12
2 Normative references . 12
3 Terms, definitions, symbols, abbreviated terms and conventions . 13
3.1 Terms and definitions . 13
3.1.1 Common terms and definitions . 14
3.1.2 CPF 8: Additional terms and definitions . 20
3.2 Symbols and abbreviated terms . 21
3.2.1 Common symbols and abbreviated terms . 21
3.2.2 CPF 8: Additional symbols and abbreviated terms . 22
3.3 Conventions . 22
4 Overview . 22
5 General . 22
6 Safety communication layer services . 22
7 Safety communication layer protocol . 23
8 Safety communication layer management . 23
9 System requirements . 23
10 Assessment . 23
11 FSCP 8/1 . 23
11.1 Scope – FSCP 8/1 . 23
11.2 Normative references – FSCP 8/1 . 23
11.3 Terms, definitions, symbols, abbreviated terms and conventions – FSCP 8/1 . 23
11.4 Overview of FSCP 8/1 (CC-Link Safety™) . 23
11.5 General – FSCP 8/1 . 24
11.5.1 External documents providing specifications for the profile . 24
11.5.2 Safety functional requirements . 24
11.5.3 Safety measures . 24
11.5.4 Safety communication layer structure . 26
11.5.5 Relationships with FAL (and DLL, PhL) . 27
11.6 Safety communication layer services for FSCP 8/1 . 27
11.6.1 General . 27
11.6.2 SASEs . 27
11.6.3 SARs . 28
11.6.4 Process data SAR ASEs . 29
11.7 Safety communication layer protocol for FSCP 8/1 . 30
11.7.1 Safety PDU format . 30
11.7.2 State description . 38
11.8 Safety communication layer management for FSCP 8/1 . 43
11.8.1 General . 43
11.8.2 Connection establishment and confirmation processing . 43
11.8.3 Safety slave verification . 43
11.9 System requirements for FSCP 8/1 . 44
IEC 61784-3-8:2021 IEC 2021 – 3 –
11.9.1 Indicators and switches . 44
11.9.2 Installation guidelines . 45
11.9.3 Safety function response time . 45
11.9.4 Duration of demands . 47
11.9.5 Constraints for calculation of system characteristics . 47
11.9.6 Maintenance . 47
11.9.7 Safety manual . 47
11.10 Assessment for FSCP 8/1 . 47
12 FSCP 8/2 . 48
12.1 Scope – FSCP 8/2 . 48
12.2 Normative references – FSCP 8/2 . 48
12.3 Terms, definitions, symbols, abbreviated terms and conventions – FSCP 8/2 . 48
12.4 Overview of FSCP 8/2 (CC-Link IE™ Safety communication function) . 48
12.5 General – FSCP 8/2 . 48
12.5.1 External documents providing specifications for the profile . 48
12.5.2 Safety functional requirements . 49
12.5.3 Safety measures . 49
12.5.4 Safety communication layer structure . 54
12.5.5 Relationships with FAL (and DLL, PhL) . 55
12.6 Safety communication layer services for FSCP 8/2 . 55
12.6.1 General . 55
12.6.2 Connection reestablishment services . 55
12.6.3 Data transmission services . 56
12.6.4 Connection termination notification services . 57
12.7 Safety communication layer protocol for FSCP 8/2 . 57
12.7.1 Safety PDU format . 57
12.7.2 Safety FAL service protocol machine (SFSPM) . 64
12.8 Safety communication layer management for FSCP 8/2 . 90
12.8.1 Parameter Definitions . 90
12.8.2 Parameter Setup . 94
12.8.3 Management Services . 95
12.9 System requirements for FSCP 8/2 . 98
12.9.1 Indicators and switches . 98
12.9.2 Installation guidelines . 100
12.9.3 Safety function response time . 100
12.9.4 Duration of demands . 101
12.9.5 Constraints for calculation of system characteristics . 101
12.9.6 Maintenance . 102
12.9.7 Safety manual . 102
12.10 Assessment for FSCP 8/2 . 103
Annex A (informative) Additional information for functional safety communication
profiles of CPF 8 . 104
A.1 Hash function calculation for FSCP 8/1 . 104
A.2 Hash function calculation for FSCP 8/2 . 104
A.3 Meaning of response time calculation formula for FSCP 8/2 . 105
Annex B (informative) Information for assessment of the functional safety
communication profiles of CPF 8. 107
Bibliography . 108
– 4 – IEC 61784-3-8:2021 IEC 2021
Figure 1 – Relationships of IEC 61784-3 with other standards (machinery) . 9
Figure 2 – Relationships of IEC 61784-3 with other standards (process) . 10
Figure 3 – Relationship between SCL and the other layers of IEC 61158 Type 18 . 27
Figure 4 – State diagram . 39
Figure 5 – Detection of unintended repetition . 51
Figure 6 – Detection of incorrect sequence . 51
Figure 7 – Detection of loss . 52
Figure 8 – Detection of unacceptable delay by time stamps . 53
Figure 9 – Detection of unacceptable delay by timer . 53
Figure 10 – Protocol Hierarchy. 54
Figure 11 – Safety PDU Structure . 58
Figure 12 – CTRL Configuration . 59
Figure 13 – SASE-M and SASE-S TS . 62
Figure 14 – S-Data during safety refresh . 62
Figure 15 – S-Data not during safety refresh . 63
Figure 16 – S-Data header configuration . 63
Figure 17 – CRC calculation . 64
Figure 18 – Communication models . 64
Figure 19 – SFSPM state transition diagram . 65
Figure 20 – Connection establishment sequence . 67
Figure 21 – Optional sequence during connection establishment sequence . 68
Figure 22 – Communication sequence during safety refresh communication . 68
Figure 23 – Offset measurement and generation sequence during safety refresh
communication . 69
Figure 24 – SFSPM-M state transition diagram . 70
Figure 25 – Sequence other than during safety refresh . 74
Figure 26 – S-Connect-req . 74
Figure 27 – S-InitConfirmNetPrm-req . 75
Figure 28 – net_prm_list . 75
Figure 29 – S-InitVerifyStnPrm-req . 75
Figure 30 – stn_prm_list . 76
Figure 31 – S-InvokeFunc-req . 76
Figure 32 – S-WriteErrorInfo-req . 77
Figure 33 – date_and_time_of_occurence . 78
Figure 34 – SFSPM-S state transition diagram . 79
Figure 35 – Sequence other than during safety refresh . 84
Figure 36 – S-Connect-rsp . 84
Figure 37 – S-InitConfirmNetPrm-rsp . 85
Figure 38 – S-InitVerifyStnPrm-rsp . 85
Figure 39 – S-InvokeFunc-rsp . 86
Figure 40 – Offset calculation procedure of safety clock . 87
Figure 41 – Relationship between transmission interval fluctuation and
transmission_interval . 91
Figure 42 – Calculation of allowable_refresh_interval . 93
IEC 61784-3-8:2021 IEC 2021 – 5 –
Figure 43 – Calculation of allowable_delay . 94
Figure 44 – Calculation of response time between safety PLCs . 100
Figure 45 – Constraints on N and m . 102
SE
Figure A.1 – Allowable_delay and offset calculation deviation . 105
Table 1 – Selection of the various measures for possible errors . 25
Table 2 – M1 safety device manager attribute format . 31
Table 3 – S1 safety device manager attribute format. 31
Table 4 – M1 safety connection manager attribute format . 31
Table 5 – S1 safety connection manager attribute format . 31
Table 6 – M1 safety cyclic transmission attribute format . 32
Table 7 – S1 safety cyclic transmission attribute format . 33
Table 8 – M1 safety device manager attribute encoding . 33
Table 9 – S1 safety device manager attribute encoding . 34
Table 10 – M1 safety connection manager attribute encoding . 34
Table 11 – S1 safety connection manager attribute encoding . 34
Table 12 – M1 safety cyclic transmission attribute encoding . 35
Table 13 – S1 safety cyclic transmission attribute encoding . 37
Table 14 – Safety master monitor timer operation . 41
Table 15 – Safety slave monitor timer operation . 41
Table 16 – Safety data monitor timer operation . 41
Table 17 – Details of connection establishment and confirmation processing . 43
Table 18 – Details of slave information verification processing . 43
Table 19 – Details of safety slave parameter transmission processing . 44
Table 20 – Monitor LEDs . 45
Table 21 – Safety function response time calculation . 46
Table 22 – Safety function response time definition of terms . 46
Table 23 – Selection of the various measures for possible errors . 50
Table 24 – SS-Start . 55
Table 25 – SS-Restart . 55
Table 26 – SS-InvokeFunc . 56
Table 27 – SS-Read . 56
Table 28 – SS-Write. 57
Table 29 – SS-Terminate . 57
Table 30 – Safety PDU elements . 58
Table 31 – CTRL Elements . 59
Table 32 – State list . 65
Table 33 – SFSPM-M timers . 70
Table 34 – SFSPM-M state transition table . 71
Table 35 – support_functions . 74
Table 36 – error_category . 77
Table 37 – error_category for AL errors . 77
Table 38 – error_code . 78
– 6 – IEC 61784-3-8:2021 IEC 2021
Table 39 – SFSPM-S timers . 79
Table 40 – SFSPM-S state transition table . 80
Table 41 – Parameters used by safety communication layer . 90
Table 42 – SM-SetSafetyStationInfo . 95
Table 43 – Safety station information setting parameters of SM-SetSafetyStationInfo . 95
Table 44 – SM-SetSafetyNetworkParameter . 96
Table 45 – Safety network parameters of SM-SetSafetyNetworkParameter . 96
Table 46 – SM-GetSafetyStationInfo . 96
Table 47 – Safety station information parameters of SM-GetSafetyStationInfo
(Request) . 97
Table 48 – Safety station information parameters of SM-GetSafetyStationInfo
(Response) . 97
Table 49 – SM-GetSafetyNetworkParameter . 97
Table 50 – Parameters of SM-GetSafetyNetworkParameter request. 97
Table 51 – Parameters of SM-GetSafetyNetworkParameter response . 98
Table 52 – Monitor LEDs . 99
Table 53 – Communication port monitor LEDs . 99
Table A.1 – Residual error probability for FSCP 8/1 CRC . 104
Table A.2 – Residual error probability for FSCP 8/2 CRC . 105
IEC 61784-3-8:2021 IEC 2021 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
PROFILES –
Part 3-8: Functional safety fieldbuses –
Additional specifications for CPF 8
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 61784-3-8 has been prepared by subcommittee 65C: Industrial networks, of IEC technical
committee 65: Industrial-process measurement, control and automation. It is an International
Standard.
This third edition cancels and replaces the second edition published in 2016. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
• structured for compliance with IEC 61784-3 Ed.4;
• general editorial changes and clarifications;
• safety measures (11.5.3);
– 8 – IEC 61784-3-8:2021 IEC 2021
• safety application service elements (11.6.2);
• safety PDU format (11.7.1);
• constraints for calculations of system characteristics (11.9.5);
• safety measures (12.5.3);
• safety PDU format (12.7.1);
• behaviour (12.7.2);
• constraints for calculations of system characteristics (12.9.5);
• hash function calculations (Annex A).
The text of this International Standard is based on the following documents:
FDIS Report on voting
65C/1083/FDIS 65C/1087/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement,
available at www.iec.ch/members_experts/refdocs. The main document types developed by
IEC are described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts of the IEC 61784-3 series, published under the general title Industrial
communication networks – Profiles – Functional safety fieldbuses, can be found on the IEC
website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.
IEC 61784-3-8:2021 IEC 2021 – 9 –
0 Introduction
0.1 General
The IEC 61158 (all parts) fieldbus standard together with its companion standards
IEC 61784-1 and IEC 61784-2 defines a set of communication protocols that enable
distributed control of automation applications. Fieldbus technology is now considered well
accepted and well proven. Thus fieldbus enhancements continue to emerge, addressing
applications for areas such as real time and safety-related applications.
IEC 61784-3 (all parts) explains the relevant principles for functional safety communications
with reference to IEC 61508 (all parts) and specifies several safety communication layers
(profiles and corresponding protocols) based on the communication profiles and protocol
layers of IEC 61784-1, IEC 61784-2 and IEC 61158 (all parts). It does not cover electrical
safety and intrinsic safety aspects. It also does not cover security aspects, nor does it provide
any requirements for security.
Figure 1 shows the relationships between IEC 61784-3 (all parts) and relevant safety and
fieldbus standards in a machinery environment.
NOTE IEC 62061 specifies the relationship between PL (Category) and SIL.
Figure 1 – Relationships of IEC 61784-3 with other standards (machinery)
Figure 2 shows the relationships between IEC 61784-3 (all parts) and relevant safety and
fieldbus standards in a process environment.
– 10 – IEC 61784-3-8:2021 IEC 2021
a
For specified electromagnetic environments; otherwise IEC 61326-3-1 or IEC 61000-6-7.
Figure 2 – Relationships of IEC 61784-3 with other standards (process)
Safety communication layers which are implemented as parts of safety-related systems
according to IEC 61508 (all parts) provide the necessary confidence in the transportation of
messages (information) between two or more participants on a fieldbus in a safety-related
system, or sufficient confidence of safe behaviour in the event of fieldbus errors or failures.
Safety communication layers specified in IEC 61784-3 (all parts) do this in such a way that a
fieldbus can be used for applications requiring functional safety up to the Safety Integrity
Level (SIL) specified by its corresponding functional safety communication profile.
The resulting SIL claim of a system depends on the implementation of the selected functional
safety communication profile (FSCP) within this system – implementation of a functional
safety communication profile in a standard device is not sufficient to qualify it as a safety
device.
IEC 61784-3 (all parts) describes:
• basic principles for implementing the requirements of IEC 61508 (all parts) for safety-
related data communications, including possible transmission faults, remedial measures
and considerations affecting data integrity;
• functional safety communication profiles for several communication profile families in
IEC 61784-1 and IEC 61784-2, including safety layer extensions to the communication
service and protocols sections of IEC 61158 (all parts).
IEC 61784-3-8:2021 IEC 2021 – 11 –
0.2 Patent declaration
The International Electrotechnical Commission (IEC) draws attention to the fact that it is
claimed that compliance with this document may involve the use of a patent concerning the
functional safety communication profiles for family 8. IEC takes no position concerning the
evidence, validity, and scope of this patent right.
The holder of this patent right has assured IEC that s/he is willing to negotiate licences under
reasonable and non-discriminatory terms and conditions with applicants throughout the world.
In this respect, the statement of the holder of this patent right is registered with IEC.
Information may be
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