EN 61158-4-3:2012

SLOVENSKI STANDARD
01-julij-2012
1DGRPHãþD
SIST EN 61158-4-3:2008
Industrijska komunikacijska omrežja - Specifikacije za procesna vodila - 4-3. del:
Specifikacija protokola na nivoju podatkovnih povezav - Elementi tipa 3 (IEC 61158
-4-3:2010)
Industrial communication networks - Fieldbus specifications - Part 4-3: Data-link layer
protocol specification - Type 3 elements (IEC 61158-4-3:2010)
Industrielle Kommunikationsnetze - Feldbusse - Teil 4-3: Protokollspezifikation des Data
Link Layer (Sicherungsschicht) - Typ 3-Elemente (IEC 61158-4-3:2010)
Réseaux de communication industriels - Spécifications de bus de terrain - Partie 4-3:
Spécification du protocole de couche de liaison de données - Eléments de Type 3 (CEI
61158-4-3:2010)
Ta slovenski standard je istoveten z: EN 61158-4-3:2012
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
35.100.20 Podatkovni povezovalni sloj Data link layer
35.110 Omreževanje Networking
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 61158-4-3
NORME EUROPÉENNE
May 2012
EUROPÄISCHE NORM
ICS 25.040.40; 35.100.20; 35.110 Supersedes EN 61158-4-3:2008

English version
Industrial communication networks -
Fieldbus specifications -
Part 4-3: Data-link layer protocol specification -
Type 3 elements
(IEC 61158-4-3:2010)
Réseaux de communication industriels -  Industrielle Kommunikationsnetze -
Spécifications de bus de terrain - Feldbusse -
Partie 4-3: Spécification du protocole de Teil 4-3: Protokollspezifikation des Data
couche de liaison de données - Link Layer (Sicherungsschicht) -
Eléments de Type 3 Typ 3-Elemente
(CEI 61158-4-3:2010) (IEC 61158-4-3:2010)

This European Standard was approved by CENELEC on 2012-03-28. 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, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland, Turkey and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2012 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61158-4-3:2012 E
Foreword
The text of document 65C/605/FDIS, future edition 2 of IEC 61158-4-3, 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 61158-4-3:2012.

The following dates are fixed:
(dop) 2012-12-28
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2015-03-28
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61158-4-3:2008.
3:2008:
— Corrections in Table A.15 and Table A.16;
— Expired patent removed and added new patents.
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.
Endorsement notice
The text of the International Standard IEC 61158-4-3:2010 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 60870-5-1 NOTE  Harmonized as EN 60870-5-1.
IEC/TR 61158-1 NOTE  Harmonized as CLC/TR 61158-1.
IEC 61158-5-3 NOTE  Harmonized as EN 61158-5-3.
IEC 61158-6-3 NOTE  Harmonized as EN 61158-6-3.

- 3 - EN 61158-4-3:2012
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  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 61158-2 2010 Industrial communication networks - Fieldbus EN 61158-2 2010
specifications -
Part 2: Physical layer specification and service
definition
IEC 61158-3-3 2007 Industrial communication networks - Fieldbus EN 61158-3-3 2008
specifications -
Part 3-3: Data-link layer service definition -
Type 3 elements
ISO/IEC 2022 - Information technology - Character code - -
structure and extension techniques

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 10731 - Information technology - Open Systems - -
Interconnection - Basic reference model -
Conventions for the definition of OSI services

ISO 1177 - Information processing - Character structure - -
for start/stop and synchronous character-
oriented transmission
IEC 61158-4-3 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
Industrial communication networks – Fieldbus specifications –
Part 4-3: Data-link layer protocol specification – Type 3 elements

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XH
ICS 25.04.40; 35.100.20; 35.110 ISBN 978-2-88912-085-7
– 2 – 61158-4-3 © IEC:2010(E)
CONTENTS
FOREWORD.6
INTRODUCTION.8
1 Scope.10
1.1 General .10
1.2 Specifications.10
1.3 Procedures.10
1.4 Applicability.10
1.5 Conformance.11
2 Normative references .11
3 Terms, definitions, symbols and abbreviations.11
3.1 Reference model terms and definitions.11
3.2 Service convention terms and definitions.13
3.3 Common terms and definitions .14
3.4 Additional Type 3 definitions.16
3.5 Common symbols and abbreviations .18
3.6 Type 3 symbols and abbreviations.19
4 Common DL-protocol elements.23
4.1 Frame check sequence .23
5 Overview of the DL-protocol .25
5.1 General .25
5.2 Overview of the medium access control and transmission protocol .26
5.3 Transmission modes and DL-entity.27
5.4 Service assumed from the PhL .32
5.5 Operational elements .35
5.6 Cycle and system reaction times .50
6 General structure and encoding of DLPDUs, and related elements of procedure .53
6.1 DLPDU granularity .53
6.2 Length octet (LE, LEr) .54
6.3 Address octet .55
6.4 Control octet (FC).57
6.5 DLPDU content error detection.61
6.6 DATA_UNIT .62
6.7 Error control procedures.62
7 DLPDU-specific structure, encoding and elements of procedure .63
7.1 DLPDUs of fixed length with no data field.63
7.2 DLPDUs of fixed length with data field.65
7.3 DLPDUs with variable data field length.67
7.4 Token DLPDU .68
7.5 ASP DLPDU .69
7.6 SYNCH DLPDU .69
7.7 Time Event (TE) DLPDU.69
7.8 Clock Value (CV) DLPDU .69
7.9 Transmission procedures .70
8 Other DLE elements of procedure.73
8.1 DL-entity initialization .73
8.2 States of the media access control of the DL-entity .73

61158-4-3 © IEC:2010(E) – 3 –
8.3 Clock synchronization protocol .79
Annex A (normative) DL-Protocol state machines .84
Annex B (informative) Type 3 (synchronous): exemplary FCS implementations. 160
Annex C (informative) Type 3: Exemplary token procedure and message transfer
periods .162
Bibliography.170

Figure 1 – Relationships of DLSAPs, DLSAP-addresses and group DL-addresses .15
Figure 2 – Logical token-passing ring .28
Figure 3 – PhL data service for asynchronous transmission .32
Figure 4 – Idle time T .38
ID1
Figure 5 – Idle time T (SDN, CS) .38
ID2
Figure 6 – Idle time T (MSRD) .38
ID2
Figure 7 – Slot time T .39
SL1
Figure 8 – Slot time T .39
SL2
Figure 9 – Slot time T .44
SL1
Figure 10 – Slot time T .44
SL2
Figure 11 – Token transfer period .50
Figure 12 – Message transfer period.51
Figure 13 – UART character .54
Figure 14 – Octet structure .54
Figure 15 – Length octet coding.55
Figure 16 – Address octet coding.55
Figure 17 – DAE/SAE octet in the DLPDU.56
Figure 18 – Address extension octet .56
Figure 19 – FC octet coding for send/request DLPDUs .58
Figure 20 – FC octet coding for acknowledgement or response DLPDUs .58
Figure 21 – FCS octet coding.61
Figure 22 – Data field .62
Figure 23 – Ident user data.62
Figure 24 – DLPDUs of fixed length with no data field.64
Figure 25 – DLPDUs of fixed length with no data field.65
Figure 26 – DLPDUs of fixed length with data field .66
Figure 27 – DLPDUs of fixed length with data field .66
Figure 28 – DLPDUs with variable data field length.67
Figure 29 – DLPDUs with variable data field length.68
Figure 30 – Token DLPDU .68
Figure 31 – Token DLPDU .69
Figure 32 – Send/request DLPDU of fixed length with no data .70
Figure 33 – Token DLPDU and send/request DLPDU of fixed length with data.70
Figure 34 – Send/request DLPDU with variable data field length.71
Figure 35 – Send/request DLPDU of fixed length with no data .71
Figure 36 – Token DLPDU and send/request DLPDU of fixed length with data.72

– 4 – 61158-4-3 © IEC:2010(E)
Figure 37 – Send/request DLPDU with variable data field length.72
Figure 38 – DL-state-diagram .74
Figure 39 – Overview of clock synchronization.80
Figure 40 – Time master state machine .81
Figure 41 – Time receiver state machine .82
Figure 42 – Clock synchronization .83
Figure A.1 – Structuring of the protocol machines.85
Figure A.2 – Structure of the SRU Machine.142
Figure B.1 – Example of FCS generation for Type 3 (synchronous) . 160
Figure B.2 – Example of FCS syndrome checking on reception for Type 3
(synchronous).160
Figure C.1 – Derivation of the token holding time (T ).163
TH
Figure C.2 – No usage of token holding time (T ).164
TH
Figure C.3 – Usage of token holding time (T ) for message transfer (equivalence
TH
between T of each Master station).165
TH
Figure C.4 – Usage of token holding time (T ) in different working load situations . 167
TH
Table 1 – FCS length, polynomials and constants by Type 3 synchronous .24
Table 2 – Characteristic features of the fieldbus data-link protocol.26
Table 3 – Transmission function code .59
Table 4 – FCB, FCV in responder .61
Table 5 – Operating parameters .73
Table A.1 – Assignment of state machines.86
Table A.2 – Data resource .87
Table A.3 – Primitives issued by DL-User to FLC.91
Table A.4 – Primitives issued by FLC to DL-User.91
Table A.5 – Primitives issued by DL-User to DLM .93
Table A.6 – Primitives issued by DLM to DL-User .94
Table A.7 – Parameters used with primitives exchanged between DL-User and FLC.94
Table A.8 – Parameters used with primitives exchanged between DL-User and DLM .95
Table A.9 – FLC/DLM state table .96
Table A.10 – FLC / DLM function table.108
Table A.11 – Primitives issued by DLM to MAC.115
Table A.12 – Primitives issued by MAC to DLM.115
Table A.13 – Parameters used with primitives exchanged between DLM and MAC . 115
Table A.14 – Local MAC variables .116
Table A.15 – MAC state table .116
Table A.16 – MAC function table.137
Table A.17 – Primitives issued by DLM to SRC.144
Table A.18 – Primitives issued by SRC to DLM.144
Table A.19 – Primitives issued by MAC to SRC.144
Table A.20 – Primitives issued by SRC to MAC.145
Table A.21 – Parameters used with primitives exchanged between MAC and SRC .145
Table A.22 – FC structure.145

61158-4-3 © IEC:2010(E) – 5 –
Table A.23 – Local variables of SRC.146
Table A.24 – SRC state table.147
Table A.25 – SRC functions .159

– 6 – 61158-4-3 © IEC:2010(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 4-3: Data-link layer protocol specification –
Type 3 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.
International Standard IEC 61158-4-3 has been prepared by subcommittee 65C: Industrial
networks, of IEC technical committee 65: Industrial-process measurement, control and
automation.
This second edition cancels and replaces the first edition published in 2007. This edition
constitutes a technical revision.
The main changes with respect to the previous edition are listed below:
• Corrections in Table A.15 and Table A.16;
• Expired patent removed and added new patents.

61158-4-3 © IEC:2010(E) – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
65C/605/FDIS 65C/619/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.
NOTE The revision of this standard will be synchronized with the other parts of the IEC 61158 series.

– 8 – 61158-4-3 © IEC:2010(E)
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/TR 61158-1.
The data-link protocol provides the data-link service by making use of the services available
from the physical 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 data-link
entities (DLEs) 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:
a) as a guide for implementors and designers;
b) for use in the testing and procurement of equipment;
c) as part of an agreement for the admittance of systems into the open systems environment;
d) 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.
NOTE Use of some of the associated protocol types is restricted by their 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 particular data-link layer protocol type to be used with physical layer and application layer protocols in Type
combinations as specified explicitly in its profile parts. Use of the various protocol types in other combinations may
require permission from their respective intellectual-property-right holders.
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 Type
3 elements and possibly other types given in the normative elements of this standard.
The following patent rights for Type 3 have been announced by [SI]:
Publication Title
EP0604668-A1 Logical ring with monitoring of rotation time
(06.07.1994);
EP0604668-B1
(18.02.1998)
EP0604669-A1 Bus system with monitoring of the activity state of participants
(06.07.1994);
EP0604669-B1
(01.04.1998)
IEC takes no position concerning the evidence, validity and scope of these patent rights.
The holder of these patent rights has assured the IEC that he/she is willing to negotiate
licences either free of charge or under reasonable and non-discriminatory terms and
conditions with applicants throughout the world. In this respect, the statement of the holder of
these patent rights is registered with IEC. Information may be obtained from:

61158-4-3 © IEC:2010(E) – 9 –
[SI]: Siemens AG
CT IP L&T
Hr. Hans-Jörg Müller
Otto-Hahn-Ring 6
D-81739 Munich
Germany
Attention is drawn to the possibility that some of the elements of this document may be the
subject of patent rights other than those identified above. IEC shall not be held responsible for
identifying any or all such patent rights.
ISO (www.iso.org/patents) and IEC (http://www.iec.ch/tctools/patent_decl.htm) maintain on-
line data bases of patents relevant to their standards. Users are encouraged to consult the
data bases for the most up to date information concerning patents.

– 10 – 61158-4-3 © IEC:2010(E)
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 4-3: Data-link layer protocol specification –
Type 3 elements
1 Scope
1.1 General
The data-link layer provides basic time-critical messaging communications between devices in
an automation environment.
This protocol provides communication opportunities to a pre-selected “master” subset of data-
link entities in a cyclic asynchronous manner, sequentially to each of those data-link entities.
Other data-link entities communicate only as permitted and delegated by those master data-
link entities.
For a given master, its communications with other data-link entities can be cyclic, or acyclic
with prioritized access, or a combination of the two.
This protocol provides a means of sharing the available communication resources in a fair
manner. There are provisions for time synchronization and for isochronous operation.
1.2 Specifications
This standard specifies
a) procedures for the timely transfer of data and control information from one data-link user
entity to a peer user entity, and among the data-link entities forming the distributed data-
link service provider;
b) the structure of the fieldbus DLPDUs used for the transfer of data and control information
by the protocol of this standard, and their representation as physical interface data units.
1.3 Procedures
The procedures are defined in terms of
a) the interactions between peer DL-entities (DLEs) through the exchange of fieldbus
DLPDUs;
b) the interactions between a DL-service (DLS) provider and a DLS-user in the same system
through the exchange of DLS primitives;
c) the interactions between a DLS-provider and a Ph-service provider in the same system
through the exchange of Ph-service primitives.
1.4 Applicability
These procedures are applicable to instances of communication between systems which
support time-critical communications services within the data-link layer of the OSI or fieldbus
reference models, and which require the ability to interconnect in an open systems
interconnection environment.
Profiles provide a simple multi-attribute means of summarizing an implementation’s
capabilities, and thus its applicability to various time-critical communications needs.

61158-4-3 © IEC:2010(E) – 11 –
1.5 Conformance
This standard also specifies conformance requirements for systems implementing these
procedures. This standard does not contain tests to demonstrate compliance with such
requirements.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 61158-2:2010 , Digital data communications for measurement and control – Fieldbus for
use in industrial control systems – Part 2: Physical layer specification and service definition
IEC 61158-3-3:2007, Industrial communication networks – Fieldbus specifications – Part 3-3:
Data link service definition – Type 3 elements
ISO/IEC 2022, Information technology – Character code structure and extension techniques
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 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
ISO 1177, Information processing – Character structure for start/stop and synchronous
character oriented transmission
Terms, definitions, symbols and abbreviations
For the purposes of this document, the following terms, definitions, symbols and abbreviations
apply.
3.1 Reference model terms and definitions
This standard is based in part on the concepts developed in ISO/IEC 7498-1 and
ISO/IEC 7498-3, and makes use of the following terms defined therein.
3.1.1 called-DL-address [ISO/IEC 7498-3]
3.1.2 calling-DL-address [ISO/IEC 7498-3]
3.1.3 centralized multi-end-point-connection [ISO/IEC 7498-3]
3.1.4 correspondent (N)-entities [ISO/IEC 7498-3]
correspondent DL-entities  (N=2)
correspondent Ph-entities  (N=1)
3.1.5 demultiplexing [ISO/IEC 7498-3]
___________
To be published.
– 12 – 61158-4-3 © IEC:2010(E)
3.1.6 DL-address [ISO/IEC 7498-3]
3.1.7 DL-address-mapping [ISO/IEC 7498-3]
3.1.8 DL-connection [ISO/IEC 7498-3]
3.1.9 DL-connection-end-point [ISO/IEC 7498-3]
3.1.10 DL-connection-end-point-identifier [ISO/IEC 7498-3]
3.1.11 DL-connection-mode transmission [ISO/IEC 7498-3]
3.1.12 DL-connectionless-mode transmission [ISO/IEC 7498-3]
3.1.13 DL-data-sink [ISO/IEC 7498-3]
3.1.14 DL-data-source [ISO/IEC 7498-3]
3.1.15 DL-duplex-transmission [ISO/IEC 7498-3]
3.1.16 DL-facility [ISO/IEC 7498-3]
3.1.17 DL-local-view [ISO/IEC 7498-3]
3.1.18 DL-name [ISO/IEC 7498-3]
3.1.19 DL-protocol [ISO/IEC 7498-3]
3.1.20 DL-protocol-connection-identifier [ISO/IEC 7498-3]
3.1.21 DL-protocol-control-information [ISO/IEC 7498-3]
3.1.22 DL-protocol-data-unit [ISO/IEC 7498-3]
3.1.23 DL-protocol-version-identifier [ISO/IEC 7498-3]
3.1.24 DL-relay [ISO/IEC 7498-3]
3.1.25 DL-service-connection-identifier [ISO/IEC 7498-3]
3.1.26 DL-service-data-unit [ISO/IEC 7498-3]
3.1.27 DL-simplex-transmission [ISO/IEC 7498-3]
3.1.28 DL-subsystem [ISO/IEC 7498-3]
3.1.29 DL-user-data [ISO/IEC 7498-3]
3.1.30 flow control [ISO/IEC 7498-3]
3.1.31 layer-management [ISO/IEC 7498-3]
3.1.32 multiplexing [ISO/IEC 7498-3]
3.1.33 naming-(addressing)-authority [ISO/IEC 7498-3]
3.1.34 naming-(addressing)-domain [ISO/IEC 7498-3]
3.1.35 naming-(addressing)-subdomain [ISO/IEC 7498-3]
3.1.36 (N)-entity [ISO/IEC 7498-3]
DL-entity
Ph-entity
61158-4-3 © IEC:2010(E) – 13 –
3.1.37 (N)-interface-data-unit [ISO/IEC 7498-3]
DL-service-data-unit  (N=2)
Ph-interface-data-unit  (N=1)
3.1.38 (N)-layer [ISO/IEC 7498-3]
DL-layer  (N=2)
Ph-layer  (N=1)
3.1.39 (N)-service [ISO/IEC 7498-3]
DL-service  (N=2)
Ph-service  (N=1)
3.1.40 (N)-service-access-point [ISO/IEC 7498-3]
DL-service-access-point  (N=2)
Ph-service-access-point  (N=1)
3.1.41 (N)-service-access-point-address [ISO/IEC 7498-3]
DL-service-access-point-address  (N=2)
Ph-service-access-point-address  (N=1)
3.1.42 peer-entities [ISO/IEC 7498-3]
3.1.43 Ph-interface-control-information [ISO/IEC 7498-3]
3.1.44 Ph-interface-data [ISO/IEC 7498-3]
3.1.45 primitive name [ISO/IEC 7498-3]
3.1.46 reassembling [ISO/IEC 7498-3]
3.1.47 recombining [ISO/IEC 7498-3]
3.1.48 reset [ISO/IEC 7498-3]
3.1.49 responding-DL-address [ISO/IEC 7498-3]
3.1.50 routing [ISO/IEC 7498-3]
3.1.51 segmenting [ISO/IEC 7498-3]
3.1.52 sequencing [ISO/IEC 7498-3]
3.1.53 splitting [ISO/IEC 7498-3]
3.1.54 synonymous name [ISO/IEC 7498-3]
3.1.55 systems-management [ISO/IEC 7498-3]

3.2 Service convention terms and definitions
This standard also makes use of the following terms defined in ISO/IEC 10731 as they apply
to the data-link layer:
3.2.1 acceptor
3.2.2 asymmetrical service
3.2.3 confirm (primitive);
requestor.deliver (primitive)
3.2.4 deliver (primitive)
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3.2.5 DL-confirmed-facility
3.2.6 DL-facility
3.2.7 DL-local-view
3.2.8 DL-mandatory-facility
3.2.9 DL-non-confirmed-facility
3.2.10 DL-provider-initiated-facility
3.2.11 DL-provider-optional-facility
3.2.12 DL-service-primitive;
primitive
3.2.13 DL-service-provider
3.2.14 DL-service-user
3.2.15 DL-user-optional-facility
3.2.16 indication (primitive)
acceptor.deliver (primitive)
3.2.17 multi-peer
3.2.18 request (primitive);
requestor.submit (primitive)
3.2.19 requestor
3.2.20 response (primitive);
acceptor.submit (primitive)
3.2.21 submit (primitive)
3.2.22 symmetrical service
3.3 Common terms and definitions
NOTE Many definitions are common to more than one protocol Type; they are not necessarily used by all protocol
Types.
3.3.1
DL-segment, link, local link
single DL-subnetwork in which any of the connected DLEs may communicate directly, without
any intervening DL-relaying, whenever all of those DLEs that are participating in an instance
of communication are simultaneously attentive to the DL-subnetwork during the period(s) of
attempted communication
3.3.2
DLSAP
distinctive point at which DL-services are provided by a single DL-entity to a single higher-
layer entity
NOTE This definition, derived from ISO/IEC 7498-1, is repeated here to facilitate understanding of the critical
distinction between DLSAPs and their DL-addresses. (See Figure 1.)

61158-4-3 © IEC:2010(E) – 15 –
DLS-user-entity
DLS-user-entity
DLS-users
DLSAP DLSAP DLSAP
DLSAP-
address DLSAP-
DLSAP-
group DL-
address
addresses
address
DL-layer
DL-entity
PhSA P PhSA P
Ph-layer
NOTE 1 DLSAPs and PhSAPs are depicted as ovals spanning the boundary between two adjacent layers.
NOTE 2 DL-addresses are depicted as designating small gaps (points of access) in the DLL portion of a DLSAP.
NOTE 3 A single DL-entity may have multiple DLSAP-addresses and group DL-addresses associated with a
single DLSAP.
Figure 1 – Relationships of DLSAPs, DLSAP-addresses and group DL-addresses
3.3.3
DL(SAP)-address
either an individual DLSAP-address, designating a single DLSAP of a single DLS-user, or a
group DL-address potentially designating multiple DLSAPs, each of a single DLS-user.
NOTE This terminology is chosen because ISO/IEC 7498-3 does not permit the use of the term DLSAP-address
to designate more than a single DLSAP at a single DLS-user
3.3.4
(individual) DLSAP-address
DL-address that designates only one DLSAP within the extended link
NOTE A single DL-entity may have multiple DLSAP-addresses associated with a single DLSAP.
3.3.5
extended link
DL-subnetwork, consisting of the maximal set of links interconnected by DL-relays, sharing a
single DL-name (DL-address) space, in which any of the connected DL-entities may
communicate, one with another, either directly or with the assistance of one or more of those
intervening DL-relay entities
NOTE An extended link may be composed of just a single link.
3.3.6
frame
denigrated synonym for DLPDU
– 16 – 61158-4-3 © IEC:2010(E)
3.3.7
group DL-address
DL-address that potentially designates more than one DLSAP within the extended link. A
single DL-entity may have multiple group DL-addresses associated with a single DLSAP. A
single DL-entity also may have a single group DL-address associated with more than one
DLSAP
3.3.8
node
single DL-entity as it appears on one local link
3.3.9
receiving DLS-user
DL-service user that acts as a recipient of DL-user-data
NOTE A DL-service user can be concurrently both a sending and receiving DLS-user.
3.3.10
sending DLS-user
DL-service user that acts as a source of DL-user-data
3.4 Additional Type 3 definitions
3.4.1
acknowledge DLPDU
reply DLPDU that contains no DLSDU
3.4.2
address extension
DLSAP address or region/segment address
3.4.3
bit time
time to transmit one bit
3.4.4
confirmed message exchange
complete data transfer with request and acknowledgement or response DLPDU
3.4.5
controller_type
hardware class of the communications entity
3.4.6
current master
token holder
3.4.7
data DLPDU
DLPDU that carries a DLSDU from a local DLS-user to a remote DLS-user
3.4.8
DL_status
status that specifies the result of the execution of the associated request
3.4.9
GAP
range of station (DLE) DL-addresses from this station (TS) to its successor (NS) in the logical
token ring, excluding stations above HSA

61158-4-3 © IEC:2010(E) – 17 –
3.4.10
GAP maintenance
registration of new Master and slave stations
3.4.11
isochronous mode
special operational mode that implies both a constant (isochronous) cycle with a fixed
schedule of high and low priority mes
...