EN 61158-4-3:2008

SLOVENSKI STANDARD
01-junij-2008
1DGRPHãþD
SIST EN 61158-4:2004
Industrijska komunikacijska omrežja - Specifikacije za procesna vodila - 4-3. del:
Specifikacija protokola na nivoju podatkovnih povezav - Elementi tipa 3 (IEC 61158
-4-3:2007)
Industrial communication networks - Fieldbus specifications -- Part 4-3: Data-link layer
protocol specification - Type 3 elements
Industrielle Kommunikationsnetze - Feldbusse - Teil 4-3: Protokollspezifikation des Data
Link Layer (Sicherungsschicht) - Typ 3-Elemente
Réseaux de communication industriels - Spécifications des bus de terrain - Partie 4-3:
Spécification des protocoles des couches de liaison de données - Eléments de type 3
Ta slovenski standard je istoveten z: EN 61158-4-3:2008
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
February 2008
EUROPÄISCHE NORM
ICS 35.100.20; 25.040.40 Partially supersedes EN 61158-4:2004

English version
Industrial communication networks -
Fieldbus specifications -
Part 4-3: Data-link layer protocol specification -
Type 3 elements
(IEC 61158-4-3:2007)
Réseaux de communication industriels -  Industrielle Kommunikationsnetze -
Spécifications des bus de terrain - Feldbusse -
Partie 4-3: Spécification des protocoles Teil 4-3: Protokollspezifikation des
des couches de liaison de données - Data Link Layer (Sicherungsschicht) -
Eléments de type 3 Typ 3-Elemente
(CEI 61158-4-3:2007) (IEC 61158-4-3:2007)

This European Standard was approved by CENELEC on 2008-02-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, 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 and the United Kingdom.

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

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61158-4-3:2008 E
Foreword
The text of document 65C/474/FDIS, future edition 1 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 was approved by CENELEC as EN 61158-4-3 on 2008-02-01.
This and the other parts of the EN 61158-4 series supersede EN 61158-4:2004.
With respect to EN 61158-4:2004 the following changes were made:
– deletion of Type 6 fieldbus, and the placeholder for a Type 5 fieldbus data-link layer, for lack of market
relevance;
– addition of new fieldbus types;
– partition into multiple parts numbered 4-1, 4-2, …, 4-19.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2008-11-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2011-02-01
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 the
EN 61784 series. Use of the various protocol types in other combinations may require permission from their respective
intellectual-property-right holders.
IEC and CENELEC draw attention to the fact that it is claimed that compliance with this standard may involve the use of patents as
follows, where the [xx] notation indicates the holder of the patent right:
Type 3 and possibly other types:
DE 36 43 979 C2 [SI] Deterministisches Zugriffsverfahren nach dem Tokenprinzip für eine Datenübertragung
DE 36 43 979 A1 [SI] Deterministisches Zugriffsverfahren nach dem Tokenprinzip für eine Datenübertragung
IEC and CENELEC take no position concerning the evidence, validity and scope of these patent rights.
The holders of these patent rights have assured IEC that they are willing to negotiate licences under reasonable and non-
discriminatory terms and conditions with applicants throughout the world. In this respect, the statement of the holders of these
patent rights are registered with IEC. Information may be obtained from:
[SI]: SIEMENS AG
Ludwig Winkel
Siemensallee 84
D-76181 Karlsruhe
Germany
Attention is drawn to the possibility that some of the elements of this standard may be the subject of patent rights other than those
identified above. IEC and CENELEC shall not be held responsible for identifying any or all such patent rights.
Annex ZA has been added by CENELEC.
__________
- 3 - EN 61158-4-3:2008
Endorsement notice
The text of the International Standard IEC 61158-4-3:2007 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 60870-5-1:1993 (not modified).
IEC 61158-5-3 NOTE  Harmonized as EN 61158-5-3:2008 (not modified).
IEC 61158-6-3 NOTE  Harmonized as EN 61158-6-3:2008 (not modified).
IEC 61784-1 NOTE  Harmonized as EN 61784-1:2008 (not modified).
IEC 61784-2 NOTE  Harmonized as EN 61784-2:2008 (not modified).
ISO 9314-2 NOTE  Harmonized as EN 29314-2:1993 (not modified).
__________
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

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.

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 2007 Industrial communication networks - EN 61158-2 2008
Fieldbus specifications -
Part 2: Physical layer specification and service
definition
1) 2)
IEC 61158-3-3 - Industrial communication networks - EN 61158-3-3 2008
Fieldbus specifications -
Part 3-3: Data-link layer service definition -
Type 3 elements
1)
ISO/IEC 2022 - Information technology - Character code - -
structure and extension techniques

1) 2)
ISO/IEC 7498-1 - Information technology - Open Systems EN ISO/IEC 7498-1 1995
Interconnection - Basic Reference Model:
The Basic Model
1)
ISO/IEC 7498-3 - Information technology - Open Systems - -
Interconnection - Basic Reference Model:
Naming and addressing
1)
ISO/IEC 10731 - Information technology - Open Systems - -
Interconnection - Basic reference model -
Conventions for the definition of OSI services

1)
ISO 1177 - Information processing - Character structure - -
for start/stop and synchronous character-
oriented transmission
1)
Undated reference.
2)
Valid edition at date of issue.

IEC 61158-4-3
Edition 1.0 2007-12
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 35.100.20; 25.040.40 ISBN 2-8318-9429-8

– 2 – 61158-4-3 © IEC:2007(E)
CONTENTS
FOREWORD.6
INTRODUCTION.8
1 Scope.9
1.1 General .9
1.2 Specifications.9
1.3 Procedures.9
1.4 Applicability.9
1.5 Conformance.10
2 Normative references .10
3 Terms, definitions, symbols and abbreviations.10
3.1 Reference model terms and definitions.10
3.2 Service convention terms and definitions.12
3.3 Common terms and definitions .13
3.4 Additional Type 3 definitions.15
3.5 Common symbols and abbreviations .17
3.6 Type 3 symbols and abbreviations.18
4 Common DL-protocol elements.22
4.1 Frame check sequence .22
5 Overview of the DL-protocol .24
5.1 General .24
5.2 Overview of the medium access control and transmission protocol .25
5.3 Transmission modes and DL-entity.26
5.4 Service assumed from the PhL .31
5.5 Operational elements .34
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 .64
7.1 DLPDUs of fixed length with no data field.64
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:2007(E) – 3 –
8.3 Clock synchronization protocol .79
Annex A (normative) – DL-Protocol state machines .84
A.1 Overall structure.84
A.2 Variation of state machines in different devices .85
A.3 DL Data Resource .86
A.4 FLC / DLM.91
A.5 MAC.115
A.6 SRU .143
Annex B (informative) – Type 3 (synchronous): exemplary FCS implementations. 161
Annex C (informative) – Type 3: Exemplary token procedure and message transfer
periods .163
C.1 Procedure of token passing .163
C.2 Examples for token passing procedure . 164
C.3 Examples for message transfer periods – asynchronous transmission.169
C.4 Examples for message transfer periods – synchronous transmission. 170
Bibliography.171

Figure 1 – Relationships of DLSAPs, DLSAP-addresses and group DL-addresses .14
Figure 2 – Logical token-passing ring .27
Figure 3 – PhL data service for asynchronous transmission .31
Figure 4 – Idle time T .37
ID1
Figure 5 – Idle time T (SDN, CS) .37
ID2
Figure 6 – Idle time T (MSRD) .38
ID2
Figure 7 – Slot time T .38
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 .53
Figure 14 – Octet structure .54
Figure 15 – Length octet coding.54
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 .57
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

– 4 – 61158-4-3 © IEC:2007(E)
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
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.144
Figure B.1 – Example of FCS generation for Type 3 (synchronous) . 161
Figure B.2 – Example of FCS syndrome checking on reception for Type 3
(synchronous) .161
Figure C.1 – Derivation of the token holding time (T ).164
TH
Figure C.2 – No usage of token holding time (T ).165
TH
Figure C.3 – Usage of token holding time (T ) for message transfer (equivalence
TH
between T of each Master station) .166
TH
Figure C.4 – Usage of token holding time (T ) in different working load situations . 168
TH
Table 1 – FCS length, polynomials and constants by Type 3 synchronous .23
Table 2 – Characteristic features of the fieldbus data-link protocol.25
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.109
Table A.11 – Primitives issued by DLM to MAC.116
Table A.12 – Primitives issued by MAC to DLM.116

61158-4-3 © IEC:2007(E) – 5 –
Table A.13 – Parameters used with primitives exchanged between DLM and MAC . 116
Table A.14 – Local MAC variables .117
Table A.15 – MAC state table .117
Table A.16 – MAC function table.139
Table A.17 – Primitives issued by DLM to SRC.145
Table A.18 – Primitives issued by SRC to DLM.146
Table A.19 – Primitives issued by MAC to SRC.146
Table A.20 – Primitives issued by SRC to MAC.146
Table A.21 – Parameters used with primitives exchanged between MAC and SRC .147
Table A.22 – FC structure.147
Table A.23 – Local variables of SRC.147
Table A.24 – SRC state table.148
Table A.25 – SRC functions .160

– 6 – 61158-4-3 © IEC:2007(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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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.
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 the IEC 61784 series. Use of the various protocol types in other
combinations may require permission from their respective intellectual-property-right holders.
IEC draws attention to the fact that it is claimed that compliance with this standard may involve the use of patents
as follows, where the [xx] notation indicates the holder of the patent right:
Type 3 and possibly other types:
DE 36 43 979 C2 [SI] Deterministisches Zugriffsverfahren nach dem Tokenprinzip für eine
Datenübertragung
DE 36 43 979 A1 [SI] Deterministisches Zugriffsverfahren nach dem Tokenprinzip für eine
Datenübertragung
IEC takes no position concerning the evidence, validity and scope of these patent rights.
The holders of these patent rights have assured IEC that they are willing to negotiate licences under reasonable
and non-discriminatory terms and conditions with applicants throughout the world. In this respect, the statement of
the holders of these patent rights are registered with IEC. Information may be obtained from:
[SI]: SIEMENS AG
Ludwig Winkel
Siemensallee 84
D-76181 Karlsruhe
Germany
61158-4-3 © IEC:2007(E) – 7 –
Attention is drawn to the possibility that some of the elements of this standard 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.
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 first edition and its companion parts of the IEC 61158-4 subseries cancel and replace
IEC 61158-4:2003. This edition of this part constitutes an editorial revision.
This edition of IEC 61158-4 includes the following significant changes from the previous
edition:
a) deletion of the former Type 6 fieldbus, and the placeholder for a Type 5 fieldbus data link
layer, for lack of market relevance;
b) addition of new types of fieldbuses;
c) division of this part into multiple parts numbered -4-1, -4-2, …, -4-19.
The text of this standard is based on the following documents:
FDIS Report on voting
65C/474/FDIS 65C/485/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.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.
The list of all the parts of the IEC 61158 series, under the general title Industrial
communication networks – Fieldbus specifications, can be found on the IEC web site.

– 8 – 61158-4-3 © IEC:2007(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.

61158-4-3 © IEC:2007(E) – 9 –
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.

– 10 – 61158-4-3 © IEC:2007(E)
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 standard. 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 (Ed.4.0), 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, Digital data communications for measurement and control – Fieldbus for use
in industrial control systems – 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
3 Terms, definitions, symbols and abbreviations
For the purposes of this standard, 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 [7498-3]
3.1.2 calling-DL-address [7498-3]
3.1.3 centralized multi-end-point-connection [7498-1]
3.1.4 correspondent (N)-entities [7498-1]
correspondent DL-entities  (N=2)
correspondent Ph-entities  (N=1)
3.1.5 demultiplexing [7498-1]
3.1.6 DL-address [7498-3]
61158-4-3 © IEC:2007(E) – 11 –
3.1.7 DL-address-mapping [7498-1]
3.1.8 DL-connection [7498-1]
3.1.9 DL-connection-end-point [7498-1]
3.1.10 DL-connection-end-point-identifier [7498-1]
3.1.11 DL-connection-mode transmission [7498-1]
3.1.12 DL-connectionless-mode transmission [7498-1]
3.1.13 DL-data-sink [7498-1]
3.1.14 DL-data-source [7498-1]
3.1.15 DL-duplex-transmission [7498-1]
3.1.16 DL-facility [7498-1]
3.1.17 DL-local-view [7498-3]
3.1.18 DL-name [7498-3]
3.1.19 DL-protocol [7498-1]
3.1.20 DL-protocol-connection-identifier [7498-1]
3.1.21 DL-protocol-control-information [7498-1]
3.1.22 DL-protocol-data-unit [7498-1]
3.1.23 DL-protocol-version-identifier [7498-1]
3.1.24 DL-relay [7498-1]
3.1.25 DL-service-connection-identifier [7498-1]
3.1.26 DL-service-data-unit [7498-1]
3.1.27 DL-simplex-transmission [7498-1]
3.1.28 DL-subsystem [7498-1]
3.1.29 DL-user-data [7498-1]
3.1.30 flow control [7498-1]
3.1.31 layer-management [7498-1]
3.1.32 multiplexing [7498-3]
3.1.33 naming-(addressing)-authority [7498-3]
3.1.34 naming-(addressing)-domain [7498-3]
3.1.35 naming-(addressing)-subdomain [7498-3]
3.1.36 (N)-entity [7498-1]
DL-entity
Ph-entity
3.1.37 (N)-interface-data-unit [7498-1]
DL-service-data-unit  (N=2)
Ph-interface-data-unit  (N=1)

– 12 – 61158-4-3 © IEC:2007(E)
3.1.38 (N)-layer [7498-1]
DL-layer  (N=2)
Ph-layer  (N=1)
3.1.39 (N)-service [7498-1]
DL-service  (N=2)
Ph-service  (N=1)
3.1.40 (N)-service-access-point [7498-1]
DL-service-access-point  (N=2)
Ph-service-access-point  (N=1)
3.1.41 (N)-service-access-point-address [7498-1]
DL-service-access-point-address  (N=2)
Ph-service-access-point-address  (N=1)
3.1.42 peer-entities [7498-1]
3.1.43 Ph-interface-control-information [7498-1]
3.1.44 Ph-interface-data [7498-1]
3.1.45 primitive name [7498-3]
3.1.46 reassembling [7498-1]
3.1.47 recombining [7498-1]
3.1.48 reset [7498-1]
3.1.49 responding-DL-address [7498-3]
3.1.50 routing [7498-1]
3.1.51 segmenting [7498-1]
3.1.52 sequencing [7498-1]
3.1.53 splitting [7498-1]
3.1.54 synonymous name [7498-3]
3.1.55 systems-management [7498-1]

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)
3.2.5 DL-confirmed-facility
3.2.6 DL-facility
3.2.7 DL-local-view
61158-4-3 © IEC:2007(E) – 13 –
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.)

– 14 – 61158-4-3 © IEC:2007(E)
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 interconnecte
...