EN 61158-6-12:2014

SLOVENSKI STANDARD
01-marec-2015
1DGRPHãþD
SIST EN 61158-6-12:2012
Industrijska komunikacijska omrežja - Specifikacije za procesna vodila - 6-12. del:
Specifikacija protokola na aplikacijski ravni - Elementi tipa 12 (IEC 61158-6-
12:2014)
Industrial communication networks - Fieldbus specifications - Part 6-12: Application layer
protocol specification - Type 12 elements (IEC 61158-6-12:2014)
Industrielle Kommunikationsnetze - Feldbusse - Teil 6-12: Protokollspezifikation des
Application Layer (Anwendungsschicht) - Typ 12-Elemente (IEC 61158-6-12:2014)
Réseaux de communication industriels - Spécifications des bus de terrain - Partie 6-12:
Spécification du protocole de la couche application - Eléments de type 12 (CEI 61158-6-
12:2014)
Ta slovenski standard je istoveten z: EN 61158-6-12:2014
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
35.100.70 Uporabniški sloj Application layer
35.110 Omreževanje Networking
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 61158-6-12

NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2014
ICS 25.040.40; 35.100.70; 35.110 Supersedes EN 61158-6-12:2012
English Version
Industrial communication networks - Fieldbus specifications -
Part 6-12: Application layer protocol specification - Type 12
elements
(IEC 61158-6-12:2014)
Réseaux de communication industriels - Spécifications des Industrielle Kommunikationsnetze - Feldbusse - Teil 6-12:
bus de terrain - Partie 6-12: Spécification du protocole de la Protokollspezifikation des Application Layer
couche application - Eléments de type 12 (Anwendungsschicht) - Typ 12-Elemente
(CEI 61158-6-12:2014) (IEC 61158-6-12:2014)
This European Standard was approved by CENELEC on 2014-09-23. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, 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: Avenue Marnix 17, B-1000 Brussels
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61158-6-12:2014 E
Foreword
The text of document 65C/764/FDIS, future edition 3 of IEC 61158-6-12, 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 61158-6-12:2014.
The following dates are fixed:
(dop) 2015-06-23
• latest date by which the document has to be implemented at
national level by publication of an identical national
standard or by endorsement
(dow) 2017-09-23
• latest date by which the national standards conflicting with
the document have to be withdrawn

This document supersedes EN 61158-6-12:2012.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association.
Endorsement notice
The text of the International Standard IEC 61158-6-12:2014 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 61131-3 NOTE Harmonized as EN 61131-3.
IEC 61158-1:2014 NOTE Harmonized as EN 61158-1:2014 (not modified).
IEC 61158-4-12 NOTE Harmonized as EN 61158-4-12.
IEC 61784-1 NOTE Harmonized as EN 61784-1.
IEC 61784-2 NOTE Harmonized as EN 61784-2.

- 3 - EN 61158-6-12:2014
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When 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 61158-3-12 -  Industrial communication networks - EN 61158-3-12 -
Fieldbus specifications -
Part 3-12: Data-link layer service
definition - Type 12 elements
IEC 61158-5-12 -  Industrial communication networks - EN 61158-5-12 -
Fieldbus specifications -
Part 5-12: Application layer service
definition - Type 12 elements
IEC 61158-6 series Industrial communication networks - EN 61158-6 series
Fieldbus specifications -
Part 6: Application layer protocol
specification
ISO/IEC 7498-1 -  Information technology - Open Systems - -
Interconnection - Basic Reference Model:
The Basic Model
ISO/IEC 7498-3 -  Information technology - Open Systems - -
Interconnection - Basic Reference Model:
Naming and addressing
ISO/IEC 8802-3 -  Information technology - - -
Telecommunications and information
exchange between systems - Local and
metropolitan area networks - Specific
requirements -
Part 3: Carrier sense multiple access with
collision detection (CSMA/CD) access
method and physical layer specifications
ISO/IEC 9545 -  Information technology - Open Systems - -
Interconnection - Application layer
structure
ISO/IEC 9899 -  Information technology - Programming - -
languages - C
Publication Year Title EN/HD Year
ISO/IEC 10731 -  Information technology - Open Systems - -
Interconnection - Basic Reference
Model - Conventions for the definition of
OSI services
ISO/IEC/IEEE 60559 -  Information technology - Microprocessor - -
Systems - Floating-Point arithmetic
IEEE 802.1D -  IEEE Standard for local and metropolitan - -
area networks - Media Access Control
(MAC) Bridges
IEEE 802.1Q -  IEEE Standard for Local and metropolitan - -
area networks - Media Access Control
(MAC) Bridges and Virtual Bridges
IETF RFC 768 -  User Datagram Protocol - -
IETF RFC 791 -  Internet Protocol - DARPA Internet - -
Program Protocol Specification
IETF RFC 826 -  Ethernet Address Resolution Protocol: Or - -
Converting Network Protocol Addresses
to 48.bit Ethernet Address for
Transmission on Ethernet Hardware

IEC 61158-6-12 ®
Edition 3.0 2014-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – Fieldbus specifications –

Part 6-12: Application layer protocol specification – Type 12 elements

Réseaux de communication industriels – Spécifications des bus de terrain –

Partie 6-12: Spécification du protocole de la couche application – Éléments

de type 12
-
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XG
ICS 25.040.40; 35.100.70; 35.110 ISBN 978-2-8322-1762-7

– 2 – IEC 61158-6-12:2014 © IEC 2014
CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
1.1 General . 10
1.2 Specifications . 11
1.3 Conformance . 11
2 Normative references . 11
3 Terms, definitions, symbols, abbreviations and conventions . 12
3.1 Reference model terms and definitions . 12
3.2 Service convention terms and definitions . 13
3.3 Application layer definitions . 14
3.4 Common symbols and abbreviations . 19
3.5 Additional symbols and abbreviations . 19
3.6 Conventions . 21
4 Application layer protocol specification . 25
4.1 Operating principle . 25
4.2 Node reference model . 26
5 FAL syntax description . 27
5.1 Coding principles . 27
5.2 Data types and encoding rules . 27
5.3 AR coding . 31
5.4 SII coding . 36
5.5 Isochronous PDI coding . 40
5.6 CoE coding . 43
5.7 EoE coding . 81
5.8 FoE Coding . 89
6 FAL protocol state machines . 95
6.1 Overall structure . 95
6.2 AP-Context state machine . 97
6.3 FAL service protocol machine (FSPM) . 97
6.4 Application Relationship Protocol Machines (ARPMs) . 97
6.5 DLL mapping protocol machine (DMPM) . 137
Bibliography . 138

Figure 1 – Common structure of specific fields . 21
Figure 2 – Type description example . 23
Figure 3 – Slave Node Reference Model . 26
Figure 4 – Encoding of Time of Day value . 28
Figure 5 – Encoding of Time Difference value . 28
Figure 6 – AL Control Request structure . 31
Figure 7 – AL Control Response structure. 31
Figure 8 – AL State Changed structure . 34
Figure 9 – PDI Control type description . 34

IEC 61158-6-12:2014 © IEC 2014 – 3 –
Figure 10 – Sync Configuration type description . 35
Figure 11 – Distributed Clock sync and latch type description . 41
Figure 12 – CoE general structure . 43
Figure 13 – SDO Download Expedited Request structure . 44
Figure 14 – SDO Download Expedited Response structure . 45
Figure 15 – SDO Download Normal Request structure . 46
Figure 16 – Download SDO Segment Request structure . 48
Figure 17 – Download SDO Segment Response structure . 49
Figure 18 – SDO Upload Expedited Request structure . 49
Figure 19 – SDO Upload Expedited Response structure . 50
Figure 20 – SDO Upload Normal Response structure . 52
Figure 21 – Upload SDO Segment Request structure . 53
Figure 22 – Upload SDO Segment Response structure . 53
Figure 23 – Abort SDO Transfer Request structure . 54
Figure 24 – SDO Information Service structure . 57
Figure 25 – Get OD List Request structure. 58
Figure 26 – Get OD List Response structure . 59
Figure 27 – Get Object Description Request structure . 60
Figure 28 – Get Object Description Response structure . 61
Figure 29 – Get Entry Description Request structure. 62
Figure 30 – Get Entry Description Response structure . 63
Figure 31 – SDO Info Error Request structure . 64
Figure 32 – EoE general structure . 81
Figure 33 – EoE Timestamp structure . 82
Figure 34 – EoE Fragment Data structure . 83
Figure 35 – Set IP Parameter Request structure . 85
Figure 36 – Set IP Parameter Response structure . 86
Figure 37 – Set MAC Filter Request structure . 87
Figure 38 – Set MAC Filter Response structure . 88
Figure 39 – Read Request structure . 89
Figure 40 – Write Request structure. 90
Figure 41 – Data Request structure . 91
Figure 42 – Ack Request structure . 92
Figure 43 – Error Request structure . 93
Figure 44 – Busy Request structure . 95
Figure 45 – Relationship among Protocol Machines . 96
Figure 46 – AR Protocol machines . 97
Figure 47 – ESM Diagramm . 99

Table 1 – PDU element description example . 22
Table 2 – Example attribute description . 23
Table 3 – State machine description elements . 24
Table 4 – Description of state machine elements . 24

– 4 – IEC 61158-6-12:2014 © IEC 2014
Table 5 – Conventions used in state machines . 25
Table 6 – Transfer Syntax for bit sequences . 29
Table 7 – Transfer syntax for data type Unsignedn . 29
Table 8 – Transfer syntax for data type Integern . 30
Table 9 – AL Control Description . 31
Table 10 – AL Control Response . 32
Table 11 – AL Status Codes . 32
Table 12 – AL State Changed . 34
Table 13 – PDI Control . 35
Table 14 – PDI Configuration . 35
Table 15 – Sync Configuration . 35
Table 16 – Slave Information Interface Area . 36
Table 17 – Slave Information Interface Categories . 37
Table 18 – Mailbox Protocols Supported Types. 37
Table 19 – Categories Types . 37
Table 20 – Structure Category String . 38
Table 21 – Structure Category General . 38
Table 22 – Structure Category FMMU . 39
Table 23 – Structure Category SyncM for each Element . 39
Table 24 – Structure Category TXPDO and RXPDO for each PDO . 40
Table 25 – Structure PDO Entry . 40
Table 26 – Distributed Clock sync parameter . 42
Table 27 – Distributed Clock latch data . 43
Table 28 – CoE elements . 44
Table 29 – SDO Download Expedited Request . 45
Table 30 – SDO Download Expedited Response . 46
Table 31 – SDO Download Normal Request . 47
Table 32 – Download SDO Segment Request . 48
Table 33 – Download SDO Segment Response . 49
Table 34 – SDO Upload Expedited Request . 50
Table 35 – SDO Upload Expedited Response . 51
Table 36 – SDO Upload Normal Response . 52
Table 37 – Upload SDO Segment Request . 53
Table 38 – Upload SDO Segment Response . 54
Table 39 – Abort SDO Transfer Request . 55
Table 40 – SDO Abort Codes . 56
Table 41 – SDO Information Service . 57
Table 42 – Get OD List Request . 58
Table 43 – Get OD List Response . 59
Table 44 – Get Object Description Request . 60
Table 45 – Get Object Description Response . 61
Table 46 – Get Entry Description Request . 62
Table 47 – Get Entry Description Response . 63

IEC 61158-6-12:2014 © IEC 2014 – 5 –
Table 48 – SDO Info Error Request. 65
Table 49 – Emergency Request . 66
Table 50 – Emergency Error Codes . 67
Table 51 – Error Code . 67
Table 52 – Diagnostic Data . 68
Table 53 – Sync Manager Length Error . 68
Table 54 – Sync Manager Address Error . 68
Table 55 – Sync Manager Settings Error . 68
Table 56 – RxPDO Transmission via mailbox . 69
Table 57 – TxPDO Transmission via mailbox . 69
Table 58 – RxPDO Remote Transmission Request . 70
Table 59 – TxPDO Remote Transmission Request . 70
Table 60 – Command object structure . 71
Table 61 – Object Dictionary Structure . 71
Table 62 – Object Code Definitions . 71
Table 63 – Basic Data Type Area . 72
Table 64 – Extended Data Type Area . 73
Table 65 – Enumeration Definition . 74
Table 66 – CoE Communication Area . 74
Table 67 – Device Type . 75
Table 68 – Error Register . 76
Table 69 – Manufacturer Device Name . 76
Table 70 – Manufacturer Hardware Version . 76
Table 71 – Manufacturer Software Version . 77
Table 72 – Identity Object . 77
Table 73 – Receive PDO Mapping . 78
Table 74 – Transmit PDO Mapping . 78
Table 75 – Sync Manager Communication Type. 79
Table 76 – Sync Manager Channel 0-31 . 80
Table 77 – Sync Manager Synchronization . 81
Table 78 – Initiate EoE Request . 82
Table 79 – Initiate EoE Response . 83
Table 80 – EoE Fragment Data . 83
Table 81 – EoE Data . 84
Table 82 – Set IP Parameter Request . 85
Table 83 – Set IP Parameter Response . 86
Table 84 – EoE Result Parameter . 87
Table 85 – Set MAC Filter Request . 87
Table 86 – Set MAC Filter Response . 89
Table 87 – Read Request . 90
Table 88 – Write Request . 91
Table 89 – Data Request . 92
Table 90 – Ack Request . 93

– 6 – IEC 61158-6-12:2014 © IEC 2014
Table 91 – Error Request . 94
Table 92 – Error codes of FoE . 94
Table 93 – Busy Request . 95
Table 94 – State transitions and local management services . 99
Table 95 – Primitives issued by ESM to DL . 100
Table 96 – Primitives issued by DL to ESM . 100
Table 97 – Primitives issued by Application to ESM . 101
Table 98 – Primitives issued by ESM to Application . 101
Table 99 – ESM Variables . 102
Table 100 – ESM macros . 102
Table 101 – ESM functions . 103
Table 102 – ESM state table . 104
Table 103 – Primitives issued by Mailbox handler to DL . 115
Table 104 – Primitives issued by DL to Mailbox handler . 115
Table 105 – Primitives issued by Protocol handler to Mailbox handler . 115
Table 106 – Primitives issued by Mailbox handler to Protocol handler . 116
Table 107 – Primitives issued by Application to CoESM . 116
Table 108 – Primitives issued by CoESM to Application . 117
Table 109 – CoESM state table. 118
Table 110 – Primitives issued by Application to EoESM . 127
Table 111 – Primitives issued by EoESM to Application . 127
Table 112 – EoESM state table . 128
Table 113 – Primitives issued by Application to FoESM . 133
Table 114 – Primitives issued by FoESM to Application . 133
Table 115 – FoESM state table . 133

IEC 61158-6-12:2014 © IEC 2014 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 6-12: Application layer protocol specification –
Type 12 elements
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
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as
“IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee
interested in the subject dealt with may participate in this preparatory work. International, governmental and
non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates
closely with the International Organization for Standardization (ISO) in accordance with conditions determined
by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of
IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other
IEC Publications.
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.
Attention is drawn to the fact that the use of the associated protocol type is restricted by its
intellectual-property-right holders. In all cases, the commitment to limited release of
intellectual-property-rights made by the holders of those rights permits a layer protocol type to
be used with other layer protocols of the same type, or in other type combinations explicitly
authorized by its intellectual-property-right holders.
NOTE Combinations of protocol types are specified in IEC 61784-1 and IEC 61784-2.
International Standard IEC 61158-6-12 has been prepared by subcommittee 65C: Industrial
networks, of IEC technical committee 65: Industrial-process measurement, control and
automation.
This third edition cancels and replaces the second edition published in 2010. This edition
constitutes a technical revision. The main changes with respect to the previous edition are
listed below:
– 8 – IEC 61158-6-12:2014 © IEC 2014
• bug fixes;
• editorial improvements;
• support of Explicit Device Identification added in ESM (Clause 6).
The text of this standard is based on the following documents:
FDIS Report on voting
65C/764/FDIS 65C/774/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with ISO/IEC Directives, Part 2.
A list of all parts of the IEC 61158 series, published under the general title Industrial
communication networks – Fieldbus specifications, can be found on the IEC web site.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication 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 61158-6-12:2014 © IEC 2014 – 9 –
INTRODUCTION
This part of IEC 61158 is one of a series produced to facilitate the interconnection of
automation system components. It is related to other standards in the set as defined by the
“three-layer” fieldbus reference model described in IEC 61158-1.
The application protocol provides the application service by making use of the services
available from the data-link or other immediately lower layer. The primary aim of this standard
is to provide a set of rules for communication expressed in terms of the procedures to be
carried out by peer application entities (AEs) at the time of communication. These rules for
communication are intended to provide a sound basis for development in order to serve a
variety of purposes:
• as a guide for implementors and designers;
• for use in the testing and procurement of equipment;
• as part of an agreement for the admittance of systems into the open systems environment;
• as a refinement to the understanding of time-critical communications within OSI.
This standard is concerned, in particular, with the communication and interworking of sensors,
effectors and other automation devices. By using this standard together with other standards
positioned within the OSI or fieldbus reference models, otherwise incompatible systems may
work together in any combination.

– 10 – IEC 61158-6-12:2014 © IEC 2014
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 6-12: Application layer protocol specification –
Type 12 elements
1 Scope
1.1 General
The Fieldbus Application Layer (FAL) provides user programs with a means to access the
fieldbus communication environment. In this respect, the FAL can be viewed as a “window
between corresponding application programs.”
This standard provides common elements for basic time-critical and non-time-critical
messaging communications between application programs in an automation environment and
material specific to Type 12 fieldbus. The term “time-critical” is used to represent the
presence of a time-window, within which one or more specified actions are required to be
completed with some defined level of certainty. Failure to complete specified actions within
the time window risks failure of the applications requesting the actions, with attendant risk to
equipment, plant and possibly human life.
This standard defines in an abstract way the externally visible behavior provided by the
different Types of the fieldbus Application Layer in terms of
a) the abstract syntax defining the application layer protocol data units conveyed between
communicating application entities,
b) the transfer syntax defining the application layer protocol data units conveyed between
communicating application entities,
c) the application context state machine defining the application service behavior visible
between communicating application entities; and
d) the application relationship state machines defining the communication behavior visible
between communicating application entities; and.
The purpose of this standard is to define the protocol provided to
a) define the wire-representation of the service primitives defined in IEC 61158-5-12, and
b) define the externally visible behavior associated with their transfer.
This standard specifies the protocol of the IEC fieldbus Application Layer, in conformance
with the OSI Basic Reference Model (ISO/IEC 7498) and the OSI Application Layer Structure
(ISO/IEC 9545).
FAL services and protocols are provided by FAL application-entities (AE) contained within the
application processes. The FAL AE is composed of a set of object-oriented Application
Service Elements (ASEs) and a Layer Management Entity (LME) that manages the AE. The
ASEs provide communication services that operate on a set of related application process
object (APO) classes. One of the FAL ASEs is a management ASE that provides a common
set of services for the management of the instances of FAL classes.
Although these services specify, from the perspective of applications, how request and
responses are issued and delivered, they do not include a specification of what the requesting
and responding applications are to do with them. That is, the behavioral aspects of the
applications are not specified; only a definition of what requests and responses they can

IEC 61158-6-12:2014 © IEC 2014 – 11 –
send/receive is specified. This permits greater flexibility to the FAL users in standardizing
such object behavior. In addition to these services, some supporting services are also defined
in this standard to provide access to the FAL to control certain aspects of its operation.
1.2 Specifications
The principal objective of this standard is to specify the syntax and behavior of the application
layer protocol that conveys the application layer services defined in IEC 61158-5-12.
A secondary objective is to provide migration paths from previously-existing industrial
communications protocols. It is this latter objective which gives rise to the diversity of
protocols standardized in subparts
...