SIST EN IEC 61158-3-24:2023

SLOVENSKI STANDARD
01-november-2023
Nadomešča:
SIST EN 61158-3-24:2015
Industrijska komunikacijska omrežja - Specifikacije za procesna vodila - 3-24. del:
Definicija opravil na ravni podatkovnih povezav - Elementi tipa 24 (IEC 61158-3-
24:2023)
Industrial communication networks - Fieldbus specifications - Part 3-24: Data-link layer
service definition - Type 24 elements (IEC 61158-3-24:2023)
Industrielle Kommunikationsnetze - Feldbusse - Teil 3-24: Dienstfestlegungen des Data
Link Layer (Sicherungsschicht) - Typ 24-Elemente (IEC 61158-3-24:2023)
Réseaux de communication industriels - Spécifications des bus de terrain - Partie 3-24:
Définition des services de la couche liaison de données - Eléments de type 24 (IEC
61158-3-24:2023)
Ta slovenski standard je istoveten z: EN IEC 61158-3-24:2023
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 IEC 61158-3-24

NORME EUROPÉENNE
EUROPÄISCHE NORM April 2023
ICS 25.040.40; 35.100.20; 35.110 Supersedes EN 61158-3-24:2014
English Version
Industrial communication networks - Fieldbus specifications -
Part 3-24: Data-link layer service definition - Type 24 elements
(IEC 61158-3-24:2023)
Réseaux de communication industriels - Spécifications des Industrielle Kommunikationsnetze - Feldbusse - Teil 3-24:
bus de terrain - Partie 3-24: Définition des services de la Dienstfestlegungen des Data Link Layer
couche liaison de données - Eléments de type 24 (Sicherungsschicht) - Typ 24-Elemente
(IEC 61158-3-24:2023) (IEC 61158-3-24:2023)
This European Standard was approved by CENELEC on 2023-04-20. 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,
Türkiye 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
© 2023 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61158-3-24:2023 E

European foreword
The text of document 65C/1201/FDIS, future edition 2 of IEC 61158-3-24, 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 61158-3-
24:2023.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2024-01-20
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2026-04-20
document have to be withdrawn
This document supersedes EN 61158-3-24:2014 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.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61158-3-24:2023 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 standard indicated:
IEC 61158-1 NOTE Approved as EN IEC 61158-1
IEC 61158-2 NOTE Approved as EN 61158-2
IEC 61158-4-24 NOTE Approved as EN IEC 61158-4-24
IEC 61158-5-24 NOTE Approved as EN 61158-5-24
IEC 61158-6-24 NOTE Approved as EN 61158-6-24
IEC 61784-1 (series) NOTE Approved as EN IEC 61784-1 (series)
IEC 61784-2 (series) NOTE Approved as EN IEC 61784-2 (series)

To be published. Stage at time of publication: FprEN IEC 61784-1-X:2023.
To be published. Stage at time of publication: FprEN IEC 61784-2-X:2023.
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.cencenelec.eu.
Publication Year Title EN/HD Year
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 2005 Information technology - Open Systems - -
Interconnection - Basic Reference Model -
Conventions for the definition of OSI
services
ISO/IEC 19501 2005 Information technology - Open Distributed - -
Processing - Unified Modeling Language
(UML) Version 1.4.2
IEC 61158-3-24 ®
Edition 2.0 2023-03
INTERNATIONAL
STANDARD
colour
inside
Industrial communication networks – Fieldbus specifications –
Part 3-24: Data-link layer service definition – Type 24 elements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 25.040.40; 35.100.20; 35.110 ISBN 978-2-8322-6563-5
– 2 – IEC 61158-3-24:2023 © IEC 2023
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
1.1 General . 8
1.2 Specifications . 8
1.3 Conformance . 8
2 Normative references . 9
3 Terms, definitions, symbols, abbreviated terms and conventions . 9
3.1 Reference model terms and definitions . 9
3.2 Service convention terms and definitions . 10
3.3 Additional Type 24 data-link specific definitions . 10
3.4 Common symbols and abbreviations . 13
3.5 Additional type 24 symbols and abbreviations . 14
3.6 Common conventions . 14
3.7 Additional Type 24 conventions. 15
4 Data-link service and concepts . 15
4.1 Overview. 15
4.2 DLS-user services . 16
4.2.1 General . 16
4.2.2 Write data . 16
4.2.3 Read data . 16
4.2.4 Send data with acknowledge service (SDA) . 16
4.2.5 Send data with no-acknowledge service (SDN) . 17
4.2.6 Event . 17
4.2.7 Get status . 17
4.3 Overview of interactions . 17
4.4 Detailed specification of services and interactions . 19
4.4.1 Write data . 19
4.4.2 Read data . 20
4.4.3 Send data with acknowledge . 21
4.4.4 Send data with no-acknowledge (SDN) . 22
4.4.5 Cyclic Event . 23
5 DL-management service . 23
5.1 Overview. 23
5.1.1 General . 23
5.1.2 Reset . 23
5.1.3 Set value . 24
5.1.4 Get value . 24
5.1.5 Evaluate delay . 24
5.1.6 Set communication mode . 24
5.1.7 Start communication . 24
5.1.8 Clear error status . 24
5.1.9 DLM Event . 24
5.2 Overview of interactions . 24
5.3 Detailed specification of services and interactions . 26
5.3.1 Reset . 26

IEC 61158-3-24:2023 © IEC 2023 – 3 –
5.3.2 Set value . 27
5.3.3 Get value . 32
5.3.4 Evaluate delay . 34
5.3.5 Set communication mode . 35
5.3.6 Start communication . 37
5.3.7 Clear error . 38
5.3.8 DLM error event . 39
Bibliography . 40

Figure 1 – Sequence of primitive for set data and read data service . 18
Figure 2 – Sequence of primitive for send data with acknowledge service . 18
Figure 3 – Sequence of primitive for send data with no-acknowledge service . 19
Figure 4 – Sequence of primitives for event service . 19
Figure 5 – Sequence of primitives for Reset service . 25
Figure 6 – Sequence of primitives for Set/get value service . 25
Figure 7 – Sequence of primitives for Evaluate delay service . 26
Figure 8 – Sequence of primitives for Start communication service . 26
Figure 9 – Sequence of primitives for Event and Clear error status service . 26

Table 1 – The list of DLS service primitives and parameters . 17
Table 2 – Write data primitives and parameters . 19
Table 3 – Values of result for write data service . 20
Table 4 – Read data primitives and parameters . 20
Table 5 – Values of result for read data service . 20
Table 6 – SDA primitives and parameters . 21
Table 7 – Values of result for SDA service . 21
Table 8 – SDN primitives and parameters . 22
Table 9 – Values of result for SDN service . 22
Table 10 – Event primitives and parameters . 23
Table 11 – Values of Event_ID for event service . 23
Table 12 – The list of DLMS service primitives and parameters . 24
Table 13 – Set value primitive and parameters. 27
Table 14 – The list of parameter Var_ID of Set value request . 27
Table 15 – Data type and range of variables . 28
Table 16 – List of the values of variable Cyc_sel . 29
Table 17 – List of the values of variable T . 30
unit
Table 18 – Structure example of each element of variable IO_Map . 30
Table 19 – Data type and range of each element . 31
Table 20 – List of the values of variable Line code . 31
Table 21 – List of the values of variable Baud rate . 31
Table 22 – List of the values of variable Line code and Baud rate . 31
Table 23 – Values of result for Set value service . 32
Table 24 – Get value primitive and parameters . 32
Table 25 –The list of parameter Var_ID of Get value request . 33

– 4 – IEC 61158-3-24:2023 © IEC 2023
Table 26 – Data type and range of variables . 33
Table 27 – Error factor assign . 34
Table 28 – Values of result for Get value service . 34
Table 29 – Evaluate delay primitive and parameters . 35
Table 30 – Values of result for Set value service . 35
Table 31 – Set communication mode primitives and parameters . 36
Table 32 – Range of T . 37
M_unit
Table 33 – Values of result for set communication mode service . 37
Table 34 – Start communication service primitives and parameter . 37
Table 35 – Values of result for start communication service . 38
Table 36 – Clear error primitive and parameters . 38
Table 37 – Values of result for clear error service . 38
Table 38 – DLM error event primitive and parameters . 39
Table 39 – Value and definition of Err_Event_ID . 39

IEC 61158-3-24:2023 © IEC 2023 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-24: Data-link layer service definition –
Type 24 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,
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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.
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members of its technical committees and IEC National Committees for any personal injury, property damage or
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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 the IEC 61784-1 series and the IEC 61784-2 series.
IEC 61158-3-24 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 second edition cancels and replaces the first edition published in 2014. This edition
constitutes a technical revision.

– 6 – IEC 61158-3-24:2023 © IEC 2023
The main changes with respect to the previous edition are listed below:
• addition of a new cyclic transmission mode which called "no time slot type" in Clause 4;
• addition of some parameters for Table 14 and Table 15 in Clause 5.3.2.2;
• in Subclause 5.3.5.2, addition of some parameters for Table 31 and addition of a new
Table 32.
The text of this International Standard is based on the following documents:
Draft Report on voting
65C/1201/FDIS 65C/1242/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/publications.
A 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.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under 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 document
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 61158-3-24:2023 © IEC 2023 – 7 –
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.
Throughout the set of fieldbus standards, the term "service" refers to the abstract capability
provided by one layer of the OSI Basic Reference Model to the layer immediately above. Thus,
the data-link layer service defined in this document is a conceptual architectural service,
independent of administrative and implementation divisions.

– 8 – IEC 61158-3-24:2023 © IEC 2023
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-24: Data-link layer service definition –
Type 24 elements
1 Scope
1.1 General
This part of IEC 61158 provides common elements for basic time-critical messaging
communications between devices in an automation environment. 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 document defines in an abstract way the externally visible service provided by the Type
24 fieldbus data-link layer in terms of
• the primitive actions and events of the service;
• the interrelationship between these actions and events, and their valid sequences;
• the parameters associated with each primitive action and event, and the form which they
take.
The purpose of this document is to define the services provided to
• the Type 24 fieldbus application layer at the boundary between the application and data-link
layers of the fieldbus reference model;
• systems management at the boundary between the data-link layer and systems
management of the fieldbus reference model.
1.2 Specifications
The principal objective of this document is to specify the characteristics of conceptual data-link
layer services suitable for time-critical communications, and thus supplement the OSI Basic
Reference Model in guiding the development of data-link protocols for time-critical
communications. A secondary objective is to provide migration paths from previously-existing
industrial communications protocols.
This document can be used as the basis for formal DL-Programming-Interfaces. Nevertheless,
it is not a formal programming interface, and any such interface will need to address
implementation issues not covered by this specification, including
• the sizes and octet ordering of various multi-octet service parameters, and
• the correlation of paired request and confirm, or indication and response, primitives.
1.3 Conformance
This document does not specify individual implementations or products, nor does it constrain
the implementations of data-link entities within industrial automation systems.
There is no conformance of equipment to this data-link layer service definition standard. Instead,
conformance is achieved through implementation of the corresponding data-link protocol that
fulfills the Type 24 data-link layer services defined in this document.

IEC 61158-3-24:2023 © IEC 2023 – 9 –
2 Normative references
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 All parts of the IEC 61158 series, as well as the IEC 61784-1 series and the IEC 61784-2 series are
maintained simultaneously. Cross-references to these documents within the text therefore refer to the editions as
dated in this list of normative references.
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 10731:2005, Information technology – Open Systems Interconnection – Basic
Reference Model – Conventions for the definition of OSI services
ISO/IEC 19501:2005, Information technology – Open Distributed Processing – Unified Modeling
Language (UML) Version 1.4.2
3 Terms, definitions, symbols, abbreviated terms and conventions
For the purposes of this document, the following terms, definitions, symbols, abbreviated terms
and conventions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1 Reference model terms and definitions
This document 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 acknowledgement [ISO/IEC 7498-1]
3.1.2 correspondent (N)-entities [ISO/IEC 7498-1]
correspondent DL-entities (N=2)
correspondent Ph-entities (N=1)
3.1.3 DL-address [ISO/IEC 7498-3]
3.1.4 DL-protocol [ISO/IEC 7498-1]
3.1.5 DL-protocol-data-unit [ISO/IEC 7498-1]
3.1.6 DL-service-data-unit [ISO/IEC 7498-1]
3.1.7 DLS-user [ISO/IEC 7498-1]
3.1.8 DLS-user-data [ISO/IEC 7498-1]

– 10 – IEC 61158-3-24:2023 © IEC 2023
3.1.9 event [ISO/IEC 19501]
3.1.10 layer-management
[ISO/IEC 7498-1]
3.1.11 primitive name [ISO/IEC 7498-1]
3.1.12 reset
[ISO/IEC 7498-1]
3.1.13 segmenting [ISO/IEC 7498-1]
3.1.14 state
[ISO/IEC 19501]
3.1.15 state machine [ISO/IEC 19501]
3.1.16 systems-management
[ISO/IEC 7498-1]
3.1.17 transition [ISO/IEC 19501]
3.1.18 (N)-entity [ISO/IEC 7498-1]
DL-entity (N=2)
Ph-entity (N=1)
3.1.19 (N)-layer [ISO/IEC 7498-1]
DL-layer (N=2)
Ph-layer (N=1)
3.1.20 (N)-service [ISO/IEC 7498-1]
DL-service (N=2)
Ph-service (N=1)
3.1.21 (N)-service-access-point [ISO/IEC 7498-1]
DL-service-access-point (N=2)
Ph-service-access-point (N=1)
3.2 Service convention terms and definitions
This document also makes use of the following terms defined in ISO/IEC 10731 as they apply
to the data-link layer:
3.2.1 confirm (primitive)
3.2.2 DL-service-primitive;
primitive
3.2.3 DL-service-provider
3.2.4 DL-service-user
3.2.5 indication (primitive)
3.2.6 request (primitive)
3.2.7 requestor
3.2.8 response (primitive)
3.3 Additional Type 24 data-link specific definitions
For the purposes of this document, the following terms and definitions apply.

IEC 61158-3-24:2023 © IEC 2023 – 11 –
3.3.1
acknowledge
acknowledgement
3.3.2
acyclic transmission
non-periodic exchange of telegrams
3.3.3
C1 master
one of the network device type that initiates and control cyclic transmission
3.3.4
C1 message
message communication that C1 master operates as initiator to exchange messages with slave
or C2 master
3.3.5
C2 master
one of the network device types that has the function of monitoring all process data transmitted
through the network and initiate message communication
3.3.6
C2 message
message communication that C2 master operates as initiator to exchange messages with slave
or C1 master
3.3.7
cyclic transmission
periodic exchange of telegrams
3.3.8
data
generic term used to refer to any information carried over a fieldbus
3.3.9
device
physical entity connected to the fieldbus composed of at least one communication element (the
network element) and which has a control element and/or a final element (transducer, actuator,
etc.)
3.3.10
event driven mode
transmission mode for the application layer protocol of the communication type 24 in which a
transaction of command-response-exchanging arises as user's demands
3.3.11
frame
synonym for DLPDU
3.3.12
initiator
network device that initiates the exchange of process data or message
3.3.13
interface
shared boundary between two functional units, defined by functional characteristics, signal
characteristics, or other characteristics as appropriate

– 12 – IEC 61158-3-24:2023 © IEC 2023
3.3.14
input data
process data sent by the slave and received by the C1 master
3.3.15
message
ordered series of octets intended to convey information
Note 1 to entry: Normally used to convey information between peers at the application layer.
3.3.16
monitor slave
slave that has the function of monitoring all process data transmitted through the network
3.3.17
network
set of nodes connected by some type of communication medium, including any intervening
repeaters, bridges, routers and lower-layer gateways
3.3.18
node
• single DL-entity as it appears on one local link
• end-point of a link in a network or a point at which two or more links meet
3.3.19
output data
process data sent by the C1 master and received by the slaves
3.3.20
protocol
convention about the data formats, time sequences, and error correction in the data exchange
of communication systems
3.3.21
real-time communication
transfer of data in real-time
3.3.22
receiving DLS-user
DL-service user that acts as a recipient of DL-user-data
Note 1 to entry: A DL-service user can be concurrently both a sending and receiving DLS-user.
3.3.23
responder
network device that responds process data or message after it has been initiated by initiator
3.3.24
send data with acknowledge
data transfer service with acknowledge of reception from corresponding DLE
3.3.25
send data with no-acknowledge
data transfer service without acknowledgement of reception from corresponding DLE
3.3.26
slave
one of the network device types that accesses the medium only after it has been initiated by
C1-Maser or C2 Master
IEC 61158-3-24:2023 © IEC 2023 – 13 –
3.3.27
sending DLS-user
DL-service user that acts as a source of DL-user-data
3.3.28
station
network device embodying one node
3.3.29
topology
physical network architecture with respect to the connection between the network devices of
the communication system
3.3.30
transmission cycle
fixed time period of cyclic transmission
3.3.31
time slot
time period reserved so that initiator and responder can exchange one frame respectively
3.4 Common symbols and abbreviations
DA Destination address
DL- Data-link layer (as a prefix)
DLE DL-entity (the local active instance of the data-link layer)
DLL DL-layer
DLM DL-management
DLMS DL-management service
DLPDU DL-protocol-data-unit
DLS DL-service
DLSAP DL-service-access-point
DLSDU DL-service-data-unit
FIFO First-in first-out (queuing method)
ID Identifier
OSI Open systems interconnection
PDU Protocol data unit
Ph- Physical layer (as a prefix)
PhE Ph-entity (the local active instance of the physical layer)
PhL Ph-layer
PHY Physical layer device (specified in ISO/IEC 8802-3)
QoS Quality of service
RT Real-time
SAP Service access point
SDU Service data unit
– 14 – IEC 61158-3-24:2023 © IEC 2023
3.5 Additional type 24 symbols and abbreviations
ACK Acknowledge
C1MSG C1 message
C2MSG C2 message
I/O Input and/or output
MSG Message
Rx Receive
SDA Send data with acknowledge
SDN Send data with no-acknowledge
SM State machine
T
Transmission cycle
cycle
T
Time slot
slot
Tx Transmit
3.6 Common conventions
This document uses the descriptive conventions given in ISO/IEC 10731.
The service model, service primitives, and time-sequence diagrams used are entirely abstract
descriptions; they do not represent a specification for implementation.
Service primitives, used to represent service user/service provider interactions (see
ISO/IEC 10731), convey parameters that indicate information available in the user/provider
interaction.
This document uses a tabular format to describe the component parameters of the DLS
primitives. The parameters that apply to each group of DLS primitives are set out in tables
throughout the remainder of this document. Each table consists of up to six columns, containing
the name of the service parameter, and a column each for those primitives and parameter-
transfer directions used by the DLS:
• the request primitive's input parameters;
• the indication primitive's output parameters;
• the response primitive's input parameters; and
• the confirm primitive's output parameters.
NOTE The request, indication, response and confirm primitives are also known as requestor.submit acceptor.deliver,
acceptor.submit, and requestor.deliver primitives, respectively (see ISO/IEC 10731).
One parameter (or part of it) is listed in each row of each table. Under the appropriate service
primitive columns, a code is used to specify the type of usage of the parameter on the primitive
and parameter direction specified in the column:
M parameter is mandatory for the primitive.
U parameter is a User option, and can be provided or not depending on the
dynamic usage of the DLS-user. When not provided, a default value for the
parameter is assumed.
C parameter is conditional upon other parameters or upon the environment of the
DLS-user.
IEC 61158-3-24:2023 © IEC 2023 – 15 –
(blank) parameter is never present.
Some entries are further qualified by items in brackets. These may be a parameter-specific
constraint:
(=) indicates that the parameter is semantically equivalent to the parameter in the
service primitive to its immediate left in the table.
In any particular interface, not all parameters need to be explicitly stated. Some may be
implicitly associated with the primitive.
In the diagrams which illustrate these interfaces, dashed lines indicate cause-and-effect or time-
sequence relationships, and wavy lines indicate that events are roughly contemporaneous.
3.7 Additional Type 24 conventions
The following notation, a shortened form of the primitive classes defined in 3.2, is used in the
figures.
req request primitive
ind indication primitive
cnf confirm primitive (confirmation)
4 Data-link service and concepts
4.1 Overview
The services provided by this interface are used to utilize the following functions which are
required in factory automation system, especially in motion control system.
• Exchange I/O data between the controller and the device.
• Transfer message between the controller and the device, or between the equipment for
engineering and them.
• Exactly synchronize the controller with the device.
This interface provides the data exchange service for the above usage. For the data exchange,
this service classifies the stations into three types of C1 master, C2 master and slave. The data
exchange is executed between one master station (C1 master or C2 master) and N slave
stations. There are two types of transmission modes, cyclic transmission and acyclic
transmission.
In cyclic transmission mode, transmission is executed cyclically with an accurate period. The
transmission cycle is set by the C1 master and slave and C2 master follow it. The transmission
cycle has I/O data exchange band to transmit process data and message communication band
to transmit message. In I/O data exchange band, C1 master transmits output data to all slaves
and the slaves transmit input data to C1 master. This transmission is executed once to each
slave, to provide real-time transmission service to DLS-user. In message communication band,
transmission is executed only when DLS-user requests.
The DLE in C1 master controls transmission sequence in cyclic transmission mode. The time
period for a master station to exchange with one slave station is called time slot. There are two
types of communication sequence, one is "fixed-width time slot type" whose time slot width is
same for all stations and the other is "configurable time slot type" whose time slot can be defined
for each station. All stations shall use the same-data-length frame when the DLE adopts fixed-
width time slot type. The width of the time slot is static in both types, and it is set by DL-
management during initialization. Once cyclic communication starts, it shall not be changed.

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There is "no time slot type" which does not use time slot, as another cyclic transmission mode.
Acyclic transmission mode is used by DLS-user that operates in event driven mode. In acyclic
transmission mode, transmissions are executed sporadically. The same transmission sequence
and message communication can be executed in acyclic transmission, as in cyclic transmission
mode without fixing the transmission cycle. Though C2 message communication is also possible,
the DLS-user shall execute the arbitration of the transmission timing. In acyclic transmission
mode, the data length is fixed at 64 octets.
In acyclic transmission mode, slaves execute processing of the output data sent by the master
and processing of the data to send the input data at its own timing. Slaves do not operate
simultaneously.
This interface provides the maintenance service besides the transmission of data. The
maintenance service is described in the next clause.
4.2 DLS-user services
4.2.1 General
This clause describes notional model for data transfer service between DLE and DLS user.
Information is exchanged by DLS primitives and related parameters between DLE and DLS user.
The following services are provided to DLS user.
• Write data
• Read data
• Send data with acknowledge service (SDA)
• Send data with no-acknowledge service
...