IEC 61158-3-11:2007

Industrial communication networks - Fieldbus specifications - Part 3-11: Data-link layer service definition - Type 11 elements

IEC 61158-3-11:2007 defines in an abstract way the externally visible service provided by the Type 11 fieldbus data-link layer in terms of:
- the primitive actions and events of the service;
- the parameters associated with each primitive action and event, and the form which they take;
- and the interrelationship between these actions and events, and their valid sequences. This first edition and its companion parts of the IEC 61158-3 subseries cancel and replace IEC 61158-3:2003. This part and its Type 11 companion parts also replace IEC/PAS 62406 published in 2005. This edition of this part constitutes a technical addition. This edition includes the following changes:
- deletion of the former Type 6 fieldbus, and the placeholder for a Type 5 fieldbus data-link layer, for lack of market relevance;
- addition of new types of fieldbuses;
- division of this part into multiple parts numbered 3-1, 3-2,..., 3-19. This bilingual version (2013-07) corresponds to the monolingual English version, published in 2007-12.

Réseaux de communication industriels - Spécifications de bus de terrain - Part 3-11: Définition du service de la couche de liaison de données - Éléments de Type 11

La CEI 61158-3-11:2007 définit de manière abstraite les services visibles de l'extérieur fournis par la couche de liaison de données de bus de terrain Type 11 en termes:
- des actions et événements primitifs de service;
- des paramètres associés à chaque action primitive et événement primitif, et la forme qu'ils prennent;
- de l'interrelation entre ces actions et événements, et leurs séquences valides. Cette première édition et ses parties associées de la sous-série de la CEI 61158-3 annulent et remplacent la CEI 61158-3:2003. L'édition de cette partie constitue un ajout technique. La présente partie et son Type 11 annulent et remplacent la CEI/PAS 62406 publiée en 2006. Cette édition inclut les changements suivants:
- suppression du précédent bus de terrain de Type 6 et du réceptacle (placeholder) pour une couche de liaison de données de bus de terrain de Type 5 en raison d'un manque de pertinence commerciale;
- ajout de nouveaux types de bus de terrain;
- division de cette partie en plusieurs parties numérotées 3-1, 3-2, ...., 3-19. La présente version bilingue (2013-07) correspond à la version anglaise monolingue publiée en 2007-12.

General Information

• Status: Published
• Publication Date: 13-Dec-2007
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.100.20 - Data link layer
• Technical Committee: SC 65C - Industrial networks
• Drafting Committee: WG 9 - TC 65/SC 65C/WG 9
• Current Stage: PPUB - Publication issued
• Start Date: 14-Dec-2007
• Completion Date: 15-Nov-2007

Relations

• Replaces: IEC 61158-3:2003 - Digital data communications for measurement and control - Fieldbus for use in industrial control systems - Part 3: Data link service definition
• Effective Date: 05-Sep-2023
• Replaces: IEC PAS 62406:2005 - Real-time Ethernet TCnet (Time-Critical Control Network)
• Effective Date: 05-Sep-2023

Overview

IEC 61158-3-11:2007 - “Industrial communication networks - Fieldbus specifications - Part 3-11: Data-link layer service definition - Type 11 elements” - defines, at an abstract level, the externally visible data-link layer service for the Type 11 fieldbus. The standard specifies the primitive actions and events, their associated parameters and formats, and the valid sequences and interactions for time-critical messaging between automation devices. This edition (2007) replaces earlier IEC 61158-3:2003 and IEC/PAS 62406 and forms part of the IEC 61158 fieldbus specification series.

Key topics and technical requirements

• Abstract service definition for the Type 11 data-link layer: primitives, events and their relationships rather than implementation code.
• Time-critical communications (TCC): support for cyclic time-windowed messaging where timely delivery is essential to system safety and operation.
• Service primitives and parameters: formal lists and descriptions of request/confirm and indication/response primitives, including parameters needed by application and management layers.
• Two data services described:
  • Time-critical cyclic (TCC) data service for deterministic cyclic exchanges.
  • Sporadic message service for non-periodic, event-driven messages.
• DL-management services: primitives and interactions for management functions (Reset, Set-value, Get-value, Publisher configuration, Activate/Deactivate TCC data, etc.).
• Service conventions and addressing models: DLSAPs, DLSAP-addresses, group DL-addresses and relationships to DLCEP (data-link connection endpoint) concepts.
• Specification boundaries: the document is an abstract service specification (not a formal programming API) - implementation specifics such as octet order, buffer handling and request/confirm correlation are left to implementers.

Applications and who uses it

• Industrial automation vendors (device manufacturers, PLC and I/O vendors) implementing Type 11 fieldbus data-link protocols.
• Protocol developers and system integrators designing deterministic, time-critical networks for manufacturing, process control and safety-related systems.
• System architects and network engineers selecting fieldbus technologies for environments where bounded latency and predictable cyclic messaging are required.
• Standards and compliance teams mapping higher-layer application requirements onto a standardized data-link service model.

Related standards

• IEC 61158-4-11 - Data-link layer protocol specification (Type 11)
• ISO/IEC 7498-1, ISO/IEC 7498-3 - OSI Reference Model basics, naming and addressing
• ISO/IEC 8802-3 - LAN (CSMA/CD) references where applicable
• ISO/TR 13283 - Time-critical communications architecture and requirements

This part of IEC 61158 supports migration from legacy industrial protocols and provides a clear service-level model for building deterministic, time-critical fieldbus solutions.

Standards Content (Sample)

IEC 61158-3-11
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
Industrial communication networks – Fieldbus specifications –
Part 3-11: Data-link layer service definition – Type 11 elements

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IEC 61158-3-11
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
Industrial communication networks – Fieldbus specifications –
Part 3-11: Data-link layer service definition – Type 11 elements

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
V
ICS 35.100.20; 25.040.40 ISBN 2-8318-9415-8

– 2 – 61158-3-11 © IEC:2007(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
1.1 Overview .7
1.2 Specifications.7
1.3 Conformance.7
2 Normative references .8
3 Terms, definitions, symbols, abbreviations and conventions .8
3.1 Reference model terms and definitions.8
3.2 Service convention terms and definitions.10
3.3 Data-link service terms and definitions .10
3.4 Symbols and abbreviations.13
3.5 Common conventions .14
4 Data-link service and concept.15
4.1 Overview .15
4.2 General description of services .16
4.3 TCC data service.20
4.4 Detail description of the sporadic message data service.24
5 DL- management services .26
5.1 General .26
5.2 Facilities of the DL-management service .26
5.3 Service of the DL-management .26
5.4 Overview of interactions .27
5.5 Detail specification of service and interactions .29
Bibliography.35

Figure 1 – Relationships of DLSAPs, DLSAP-addresses and group DL-addresses .11
Figure 2 – Overall flow of data frames during one minimum cycle period (high-speed
transmission period).17
Figure 3 – Overall flow of cyclic data frames over one maximum cycle period (low-
speed transmission period) .18
Figure 4 – Sequence diagram of TCC data service .19
Figure 5 – Sequence diagram of sporadic message service .19
Figure 6 – Relationship of DLSAP, DLCEP and DLCEP-address.20
Figure 7 – Sequence diagram of Reset, Set-value, Get-value, Set-publisher-
configuration, Get-publisher-configuration, Activate-TCC-data and Deactivate-
TCC-data service primitives .28
Figure 8 – Sequence diagram of sporadic message service .28

Table 1 – Primitives and parameters used on the time-critical cyclic data service .21
Table 2 – Data request primitives and the parameters .21
Table 3 – Put buffer primitives and parameters .22
Table 4 – Get buffer primitives and parameters.23
Table 5 – Notify buffer received primitives and parameters .23

61158-3-11 © IEC:2007(E) – 3 –
Table 6 – Primitives and parameters used on sporadic message data service.24
Table 7 – Submit sporadic message primitives and parameters .25
Table 8 – Summary of DL-management primitives and parameters .28
Table 9 – DLM-Reset primitives and parameters.29
Table 10 – DLM-Set-value primitives and parameters .29
Table 11 – DLM-Get-value primitives and parameters .30
Table 12 – Event primitives and parameters .31
Table 13 – Set-publisher-configuration primitives and parameters .31
Table 14 – DLM-Get-publisher-configuration primitives and parameters.32
Table 15 – DLM-Activate-TCC primitives and the parameters .33
Table 16 – DLM-Deactivate-TCC primitives and the parameters .34

– 4 – 61158-3-11 © IEC:2007(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-11: Data-link layer service definition – Type 11 elements

FOREWORD
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
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 of their respective intellectual-property-right holders.
International Standard IEC 61158-3-11 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 61158-3 subseries cancel and replace
IEC 61158-3:2003. This edition of this part constitutes a technical addition. This part and its
Type 11 companion parts also replaces IEC/PAS 62406, published in 2005.

61158-3-11 © IEC:2007(E) – 5 –
This edition includes the following significant changes with respect to 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 3-1, 3-2, …, 3-19.
The text of this standard is based on the following documents:
FDIS Report on voting
65C/473/FDIS 65C/484/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.

– 6 – 61158-3-11 © 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.
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 standard is a conceptual architectural service,
independent of administrative and implementation divisions.

61158-3-11 © IEC:2007(E) – 7 –
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-11: Data-link layer service definition – Type 11 elements

1 Scope
1.1 Overview
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 standard defines in an abstract way the externally visible service provided by the
Type 11 fieldbus data-link layer in terms of
a) the primitive actions and events of the service;
b) the parameters associated with each primitive action and event, and the form which they
take; and
c) the interrelationship between these actions and events, and their valid sequences.
The purpose of this standard is to define the services provided to
• the Type 11 fieldbus application layer at the boundary between the application and data-
link layers of the fieldbus reference model, and
• 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 standard 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 specification may 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
a) the sizes and octet ordering of various multi-octet service parameters, and
b) the correlation of paired request and confirm, or indication and response, primitives.
1.3 Conformance
This standard do not specify individual implementations or products, nor do they 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 11 data-link layer services defined in this standard.

– 8 – 61158-3-11 © IEC:2007(E)
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 61158-4-11, Industrial communication networks – Fieldbus specifications – Part 4-11:
Data-link layer protocol specification – Type 11 elements
ISO/IEC 7498-1, Information technology – Open Systems Interconnection – Basic Reference
Model: The Basic Model
ISO/IEC 7498-3, Information technology – Open Systems Interconnection – Basic Reference
Model: Naming and addressing
ISO/IEC 8802-3, Information technology – Telecommunications and information exchange
between systems – Local and metropolitan area networks – Specific requirements – Part 3:
Carrier sense multiple access with collision detection (CSMA/CD) access method and
physical layer specifications
IISO/IEC 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
ISO/TR 13283, Industrial automation – Time-critical communications architectures – User
requirements and network management for time-critical communications systems
3 Terms, definitions, symbols, abbreviations and conventions
For the purposes of this document, the following terms, definitions, symbols, abbreviations
and conventions 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 DL-address [7498-3]
3.1.2 DL-address-mapping
[7498-1]
3.1.3 called-DL-address [7498-3]
3.1.4 calling-DL-address [7498-3]
3.1.5 centralized multi-end-point-connection [7498-1]
3.1.6 DL-connection [7498-1]
3.1.7 DL-connection-end-point [7498-1]
3.1.8 DL-connection-end-point-identifier [7498-1]
3.1.9 DL-connection-mode transmission [7498-1]
3.1.10 DL-connectionless-mode transmission
[7498-1]
3.1.11 correspondent (N)-entities [7498-1]
correspondent DL-entities  (N=2)
correspondent Ph-entities  (N=1)

61158-3-11 © IEC:2007(E) – 9 –
3.1.12 DL-duplex-transmission [7498-1]
3.1.13 (N)-entity [7498-1]
DL-entity  (N=2)
Ph-entity  (N=1)
3.1.14 DL-facility [7498-1]
3.1.15 flow control [7498-1]
3.1.16 (N)-layer [7498-1]
DL-layer  (N=2)
Ph-layer  (N=1)
3.1.17 layer-management [7498-1]
3.1.18 DL-local-view [7498-3]
3.1.19 DL-name [7498-3]
3.1.20 naming-(addressing)-domain [7498-3]
3.1.21 peer-entities [7498-1]
3.1.22 primitive name [7498-3]
3.1.23 DL-protocol [7498-1]
3.1.24 DL-protocol-connection-identifier [7498-1]
3.1.25 DL-protocol-data-unit [7498-1]
3.1.26 DL-relay [7498-1]
3.1.27 reset [7498-1]
3.1.28 responding-DL-address [7498-3]
3.1.29 routing [7498-1]
3.1.30 segmenting [7498-1]
3.1.31 (N)-service [7498-1]
DL-service  (N=2)
Ph-service  (N=1)
3.1.32 (N)-service-access-point [7498-1]
DL-service-access-point  (N=2)
Ph-service-access-point  (N=1)
3.1.33 DL-service-access-point-address [7498-3]
3.1.34 DL-service-connection-identifier [7498-1]
3.1.35 DL-service-data-unit [7498-1]
3.1.36 DL-simplex-transmission [7498-1]
3.1.37 DL-subsystem [7498-1]
3.1.38 systems-management [7498-1]
3.1.39 DLS-user-data [7498-1]
– 10 – 61158-3-11 © IEC:2007(E)
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
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 DLS-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 Data-link service terms and definitions
3.3.1
common memory
virtual common memory over the Type 11 fieldbus, which is shared by the nodes participating
in the Type 11 fielbus and is primarily used for the real-time communications by the TCC data
service
3.3.2
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
61158-3-11 © IEC:2007(E) – 11 –
3.3.3
DLCEP-address
DL-address which designates either
a) one peer DL-connection-end-point, or
b) one multi-peer publisher DL-connection-end-point and implicitly the corresponding set of
subscriber DL-connection-end-points where each DL-connection-end-point exists within a
distinct DLSAP and is associated with a corresponding distinct DLSAP-address
3.3.4
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.
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
3.3.5
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.
3.3.6
(individual) DLSAP-address
DL-address that designates only one DLSAP within the extended link

– 12 – 61158-3-11 © IEC:2007(E)
NOTE  A single DL-entity may have multiple DLSAP-addresses associated with a single DLSAP.
3.3.7
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.
3.3.8
frame
denigrated synonym for DLPDU
3.3.9
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
3.3.10
high-speed cyclic data
RTE data conveyed by means of the high-speed cyclic data transmission
3.3.11
high-speed cyclic data transmission
one of three levels of the TCC data service with the highest priority level
3.3.12
low-speed cyclic data
RTE data conveyed by means of the low-speed cyclic data transmission
3.3.13
low-speed cyclic data transmission
one of three levels of the TCC data service with the lowest priority level
3.3.14
medium-speed cyclic data
RTE data conveyed by means of the medium-speed cyclic data transmission
3.3.15
medium-speed cyclic data transmission
one of three levels of the TCC data service with the second priority level
3.3.16
multipoint connection
connection from one node to many nodes. Multipoint connection allows data transfer from a
single publisher to many subscriber nodes.
3.3.17
multi-peer DLC
centralized multi-end-point DL-connection offering DL-duplex-transmission between a single
distinguished DLS-user known as the publisher or publishing DLS-user, and a set of peer but
undistinguished DLS-users known collectively as the subscribers or subscribing DLS-users,
where the publishing DLS-user can send to the subscribing DLS-users as a group (but not

61158-3-11 © IEC:2007(E) – 13 –
individually), and the subscribing DLS-users can send to the publishing DLS-user (but not to
each other).
3.3.18
node
single DL-entity as it appears on one local link
3.3.19
node-id
two-octet primary identifier for the DLE on the local link, whose values are constrained
NOTE  A permissible value is from 1 to 255. A value 0 is specifically used for the SYN node, which emits the SYN
frame.
3.3.20
receiving DLS-user
DL-service user that acts as a recipient of DLS-user-data
NOTE  A DL-service user can be concurrently both a sending and receiving DLS-user.
3.3.21
sending DLS-user
DL-service user that acts as a source of DLS-user-data
3.3.22
SYN node
node transmitting the SYN frame
3.3.23
sporadic message data service
aperiodic message transfer which sporadically occurs upon DLS-user requesting one or more
message to transfer, and regular ISO/IEC 8802-3 Ethernet message frame is transferred by
means of this message transfer
3.3.24
TCC data service
cyclic data transfer with three levels of the data transmission at the same time, of which each
data transmission level is according to the data priority and the data transmission period for
real-time delivery, and of which the data transmission period and the total data volume for
each level can be specified in designing phase and on application needs
3.4 Symbols and abbreviations
3.4.1 CM Common memory
3.4.2 DL- Data-link layer (as a prefix)
3.4.3 DLC DL-connection
3.4.4 DLCEP DL-connection-end-point
3.4.5 DLE DL-entity (the local active instance of the data-link layer)
3.4.6 DLL DL-layer
3.4.7 DLPCI DL-protocol-control-information
3.4.8 DLPDU
DL-protocol-data-unit
3.4.9 DLM DL-management
– 14 – 61158-3-11 © IEC:2007(E)
3.4.10 DLME DL-management entity (the local active instance of
DL-management)
3.4.11 DLMS DL-management service
3.4.12 DLS DL-service
3.4.13 DLSAP DL-service-access-point
3.4.14 DLSDU DL-service-data-unit
3.4.15 FIFO First-in first-out (queuing method)
3.4.16 GCM Global common memory
3.4.17 OSI Open systems interconnection
3.4.18 Ph- Physical layer (as a prefix)
3.4.19 PhE Ph-entity (the local active instance of the physical layer)
3.4.20 PhL Ph-layer
3.4.21 QoS Quality of service
3.4.22 RTE Real Time Ethernet
3.4.23 TCC Time-critical cyclic

3.5 Common conventions
This standard 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 standard 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 standard. 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:
a) the request primitive’s input parameters;
b) the request primitive’s output parameters;
c) the indication primitive’s output parameters;
d) the response primitive’s input parameters; and
e) 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: mandatory for the primitive.

61158-3-11 © IEC:2007(E) – 15 –
U Parameter: a user option which may or may not be provided 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.
(Blank) Parameter is never present.
Some entries are further qualified by items in brackets. These may be
a) 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.
b) an indication that some note applies to the entry
(n) indicates that the following note n contains additional information pertaining to
the parameter and its use.
In any particular interface, not all parameters need be explicitly stated. Some may be
implicitly associated with the DLSAP at which the primitive is issued.
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.
4 Data-link service and concept
4.1 Overview
4.1.1 General
This standard specifies the Type 11 data-link services for a ISO/IEC 8802-3-based time-
critical control network, which is one of the communication networks for Real-Time Ethernet
(RTE) defined in IEC 61784-2.
This standard meets the industrial automation market objective of providing predictable time
deterministic and reliable time-critical data transfer and means, which allow co-existence with
non-time-critical data transfer over the ISO/IEC 8802-3 series communications medium, for
support of cooperation and synchronization between automation processes on field devices in
a real-time application system. 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.
4.1.2 Field of applications
In industrial control systems, several kinds of field devices such as drives, sensors and
actuators, programmable controllers, distributed control systems (DCS) and human machine
interface (HMI) devices are required to be connected with control networks. The process
control data and the state data is transferred among these field devices in the system and the
communications between these field devices requires simplicity in application programming
and to be executed with adequate response time. In most industrial automation systems such
as food, water, sewage, paper and steel, including a rolling mill, the control network is
required to provide time-critical response capability for their application, as required in
ISO/TR 13283 for time-critical communications architectures.

– 16 – 61158-3-11 © IEC:2007(E)
Plant production may be compromised due to errors, which could be introduced to the control
system if the network does not provide a time-critical response. Therefore, the following
characteristics are required for a time-critical control network:
– deterministic response time between the control device nodes;
– ability to share process data seamlessly across the control system.
These services are applicable to such an industrial automation environment, in which time-
critical communications is primarily required. 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.
4.2 General description of services
4.2.1 General
The DLS provides for transparent and reliable transfer of data between DLS-users over a
Type 11 fieldbus. The DLS is base on services provided by the physical layer of
ISO/IEC 8802-3 to the conceptual interface between the physical and data-link layers.
Two types of data transmission services are provided.
a) TCC data service: The connection-oriented buffer transfers between pre-established
point-to-multipoint DLCEPs on the same local link.
b) Sporadic message data service: The unacknowledged connectionless message
transfers between single DLSAPs, or unacknowledged connectionless message transfer
from a single DLSAP to a group of DLSAPs on the extended link.
NOTE  For the purpose of clarity, the expressions "buffer transfer" and "message transfer" are used to distinguish
between the two types of communications services, connection-oriented and connectionless, respectively, that are
offered by this DLS,
The buffer transfer service or the TCC data service is based on cyclic data transfers of three
kinds of transmission period. The transmission periods and the total volumes of each level of
the buffer transfer by the multiple distributed DLS-providers on the same local link are defined
when the system is configured, and are based on application needs. Cyclic data transfers are
automatically triggered by the communications system without the user requesting them.
There are also three types of TCC data service according to the transmission period.
a) High-speed cyclic data transmission.
b) Medium-speed cyclic data transmission.
c) Low-speed cyclic data transmission.
The message transfer service or the sporadic message data service is based on aperiodic
data transfer, sporadically occurred upon DLS-user requesting one or more message to
transfer. The priority level and the target token rotation time, corresponding to the target time
to obtain the transmission right to send out the message data on the medium, are defined
when the system is configured, and are based on application needs. The transmit delay is
depending on the priority level and the target token rotation time. Regular ISO/IEC 8802-3
Ethernet message frame is transferred by means of this message transfer service.
The DLS provides DLS-users with a means to set up a quality of service for the transfer of
data. QoS is specified by means of QoS parameters representing aspects such as data
transmit delay, priority level, DLCEP data length, and so on. A DL-management Service
(DLMS) is defined in Clause 5.

61158-3-11 © IEC:2007(E) – 17 –
4.2.2 Overview of the Data frames flow on the medium
Overview of the data frames flow on the medium is shown in Figure 2 and Figure 3.
The DLL provides the opportunity of transferring data to each node in a sequential order and
within a predetermined time period. At the start time of every high-speed-transmission-period
(Tsyn), the SYN frame is broadcast to all Type 11 fieldbus nodes. When the SYN frame has
been received, the node with sequential number 1 (node 1) starts sending its data frames,
and after the completion of its data frames transmission node 2 can send out its data frames.
The Nth node (node N) can obtain the transmission right after the (N-1) th node completes its
data frames transmission. The sequential number is assigned to each node at the time
approval to join the Type 11 fieldbus is granted, and is up to 255.
Each node can hold the transmission right for a preset time before transfering the
transmission right to the next node. The data to be sent and the data to be retained are
determined by priority.
Data transmission includes cyclic data and sporadic message transmission. Cyclic data
transmission is divided into high, medium and low-speed cyclic data transmission. Each node
sends the high-speed cyclic data frames on each occasion when it obtains the transmission
right. The data of lower priorities, that is the medium-speed cyclic data, the sporadic message
data and the low-speed cyclic data respectively, are sent or not sent depending on the
circumstances.
Time
SYN frame SYN frame
High-speed transmission period
(Tsyn)
Node 1 Node 2 Node 3 Node n Node 1 Node 2
4 priority levels
High-speed
cyclic data
Medium-speed
cyclic data
Sporadic
message data
Low-speed
cyclic data
Figure 2 – Overall flow of data frames during one minimum cycle period
(high-speed transmission period)
The holding time of the transmission right of each node is determined by the settings of the
high-speed cyclic, the medium-speed cyclic, the sporadic message and the low-speed cyclic
data transmission periods and by the volume of transmission data for each node. After
sending all the high-speed cyclic data, the node sends the medium-speed cyclic data. If the
holding time of the transmission right ends during sending the medium-speed cyclic data, the
transmission of the medium-speed cyclic data is interrupted. Node N obtains the transmission
right again during the next high-speed transmission period, during which time all the high-
speed cyclic data and the remainder of the previous medium-speed cyclic data is sent. For the
low-speed cyclic data are sent out in this fashion.

– 18 – 61158-3-11 © IEC:2007(E)
SYN frame
Node N
Th
High-speed
Cyclic data
Tm
Medium-speed
Cyclic data
Tl
Low-speed
Cyclic data
Th: High-speed transmission period(1 Cycle period)
Tm: Medium-speed transmission period (1 Cycle period)
Tl:  Low-speed transmission period (1 Cycle period)

Figure 3 – Overall flow of cyclic data frames over one maximum cycle period
(low-speed transmission period)
4.2.3 Sequence of primitives
A request primitive is used by a DLS-user to request a service. A confirm primitive is returned
to the DLS-user upon completion of the service. Moreover, an indication primitive is used to
report to the DLS-user the receipt of new DLS-user data or the receipt of a new message.
4.2.3.1 Primitives of the TCC data service
The sequence of primitives for the TCC data service is shown in Figure 4.
DL-Data-req indication primitive informs the DLS-user initiates the data transfer using DL-Put
service from the corresponding DLS-user buffer associated with a specified DLCEP to the
send buffer of local DLE for publishing the data.
DL-Put request primitive which responds to DL-Data-req indication primitive allows the DLS-
user to transfer data of the corresponding DLS-user buffer associated with a specified DLCEP
by the DL-Data-req indication primitive to the send_buffer of the local DLE where the DLE is
the publisher.
DL-Buffer-received indication primitive informs the DLS-user that a subscribed data if a
DLCEP has just correctly received. The data in the Receive_buffer of the local DLE is updated
and is available, and is read by the DLS-user using the DL-Get request primitive.
DL-Get request primitive which responds to DL-Buffer-received indication primitive allows the
DLS-user to get the data in the receive_buffer of the local DLE and to transfer the data from
the receive_buffer to the corresponding DLS-user buffer associated with the specified DLCEP
by DL-Buffer-received indication primitive by the DLE where the DLE is the subscriber.

61158-3-11 © IEC:2007(E) – 19 –
Subscriber(s)
Publisher
DL-Data-req
indication
DL-Put
request
DL-Put
confirm DL-Buffer-received
DLPDU
DL-Get
t
DL-Get
confirm
Figure 4 – Sequence diagram of TCC data service
4.2.3.2 Sporadic message data service
The sequence of primitives on sporadic message data service is shown in Figure 5.
DL-SPDATA request and DL-SPDATA indication correspond to the MA_DATA request and
MA_DATA indication defined by ISO/IEC 8802-3 respectively.
Receiver(s)
Sender
DL-SPDATA
request
DL-SPDATA
indication
DL-SPDATA
confirm
Figure 5 – Sequence diagram of sporadic message service
4.2.4 Addressing
Two different types of addressing exist for DL-addressing shown in Figure 6: one for the TCC
data service and the other for the sporadic message data service.
For buffer transfers of the TCC data service: each variable in the system is associated with a
DLCEP-identifier that characterizes it within the system in a unique manner. Entities
participating in a buffer transfer are not identified explicitly. Rather, they are identified
indirectly as subscribers or publisher of the identified variable. Each variable has only one
publisher.
For message transfer of the sporadic message data service: One or more DLSAP-addresses
are defined within each DLE. These DLSAP-addresses give access to a message transfer
service. Each DLSAP-address identifies an access point to a message service linked to a
DLS-user entity. During the message transaction two DLSAP-addresses are indicated in order
to establish contact between the communicating entities. Each DLSAP-address specifies a
DLS-user of the message service (for both transmission and reception). This DL-address is
unique within the extended link.

– 20 – 61158-3-11 © IEC:2007(E)
Variable addressing is restricted to the local link. The addressing mechanism makes it
possible to identify variables and exchanges independent of the producing and consuming
DLEs. For buffer transfers all relationships between the various DLS-users are known and
defined when the system is configured. Each DLCEP-identifier
...

IEC 61158-3-11 ®
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial communication networks – Fieldbus specifications –
Part 3-11: Data-link layer service definition – Type 11 elements

Réseaux de communication industriels – Spécifications des bus de terrain –
Partie 3-11: Définition du service de la couche de liaison de données –
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IEC 61158-3-11 ®
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial communication networks – Fieldbus specifications –

Part 3-11: Data-link layer service definition – Type 11 elements

Réseaux de communication industriels – Spécifications des bus de terrain –

Partie 3-11: Définition du service de la couche de liaison de données –

Éléments de Type 11
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX V
ICS 25.040.40; 35.100.20 ISBN 978-2-8322-0983-7

– 2 – 61158-3-11 © IEC:2007
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
1.1 Overview . 7
1.2 Specifications . 7
1.3 Conformance . 7
2 Normative references . 8
3 Terms, definitions, symbols, abbreviations and conventions . 8
3.1 Reference model terms and definitions . 8
3.2 Service convention terms and definitions . 10
3.3 Data-link service terms and definitions . 10
3.4 Symbols and abbreviations . 13
3.5 Common conventions . 14
4 Data-link service and concept . 15
4.1 Overview . 15
4.2 General description of services . 16
4.3 TCC data service. 20
4.4 Detail description of the sporadic message data service . 24
5 DL- management services . 26
5.1 General . 26
5.2 Facilities of the DL-management service . 26
5.3 Service of the DL-management . 26
5.4 Overview of interactions . 27
5.5 Detail specification of service and interactions . 29
Bibliography . 35

Figure 1 – Relationships of DLSAPs, DLSAP-addresses and group DL-addresses . 11
Figure 2 – Overall flow of data frames during one minimum cycle period (high-speed
transmission period) . 17
Figure 3 – Overall flow of cyclic data frames over one maximum cycle period (low-
speed transmission period) . 18
Figure 4 – Sequence diagram of TCC data service . 19
Figure 5 – Sequence diagram of sporadic message service . 19
Figure 6 – Relationship of DLSAP, DLCEP and DLCEP-address . 20
Figure 7 – Sequence diagram of Reset, Set-value, Get-value, Set-publisher-
configuration, Get-publisher-configuration, Activate-TCC-data and Deactivate-TCC-
data service primitives . 28
Figure 8 – Sequence diagram of sporadic message service . 28

Table 1 – Primitives and parameters used on the time-critical cyclic data service . 21
Table 2 – Data request primitives and the parameters . 21
Table 3 – Put buffer primitives and parameters . 22
Table 4 – Get buffer primitives and parameters . 23
Table 5 – Notify buffer received primitives and parameters . 23

61158-3-11 © IEC:2007 – 3 –
Table 6 – Primitives and parameters used on sporadic message data service . 24
Table 7 – Submit sporadic message primitives and parameters . 25
Table 8 – Summary of DL-management primitives and parameters . 28
Table 9 – DLM-Reset primitives and parameters . 29
Table 10 – DLM-Set-value primitives and parameters . 29
Table 11 – DLM-Get-value primitives and parameters . 30
Table 12 – Event primitives and parameters . 31
Table 13 – Set-publisher-configuration primitives and parameters . 31
Table 14 – DLM-Get-publisher-configuration primitives and parameters . 32
Table 15 – DLM-Activate-TCC primitives and the parameters . 33
Table 16 – DLM-Deactivate-TCC primitives and the parameters . 33

– 4 – 61158-3-11 © IEC:2007
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-11: Data-link layer service definition – Type 11 elements

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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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
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other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
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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.
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 of their respective intellectual-property-right holders.
International Standard IEC 61158-3-11 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 61158-3 subseries cancel and replace
IEC 61158-3:2003. This edition of this part constitutes a technical addition. This part and its
Type 11 companion parts also replaces IEC/PAS 62406, published in 2005.
This edition includes the following significant changes with respect to the previous edition:

61158-3-11 © IEC:2007 – 5 –
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 3-1, 3-2, …, 3-19.
This bilingual version (2013-07) corresponds to the monolingual English version, published in
2007-12.
The text of this standard is based on the following documents:
FDIS Report on voting
65C/473/FDIS 65C/484/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.
The French version of this standard has not been voted upon.
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.

– 6 – 61158-3-11 © IEC:2007
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.
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 standard is a conceptual architectural service,
independent of administrative and implementation divisions.

61158-3-11 © IEC:2007 – 7 –
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-11: Data-link layer service definition – Type 11 elements

1 Scope
1.1 Overview
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 standard defines in an abstract way the externally visible service provided by the
Type 11 fieldbus data-link layer in terms of
a) the primitive actions and events of the service;
b) the parameters associated with each primitive action and event, and the form which they
take; and
c) the interrelationship between these actions and events, and their valid sequences.
The purpose of this standard is to define the services provided to
• the Type 11 fieldbus application layer at the boundary between the application and data-
link layers of the fieldbus reference model, and
• 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 standard 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 specification may 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
a) the sizes and octet ordering of various multi-octet service parameters, and
b) the correlation of paired request and confirm, or indication and response, primitives.
1.3 Conformance
This standard do not specify individual implementations or products, nor do they 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 11 data-link layer services defined in this standard.

– 8 – 61158-3-11 © IEC:2007
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 61158-4-11, Industrial communication networks – Fieldbus specifications – Part 4-11:
Data-link layer protocol specification – Type 11 elements
ISO/IEC 7498-1, Information technology – Open Systems Interconnection – Basic Reference
Model: The Basic Model
ISO/IEC 7498-3, Information technology – Open Systems Interconnection – Basic Reference
Model: Naming and addressing
ISO/IEC 8802-3, Information technology – Telecommunications and information exchange
between systems – Local and metropolitan area networks – Specific requirements – Part 3:
Carrier sense multiple access with collision detection (CSMA/CD) access method and
physical layer specifications
IISO/IEC 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
ISO/TR 13283, Industrial automation – Time-critical communications architectures – User
requirements and network management for time-critical communications systems
3 Terms, definitions, symbols, abbreviations and conventions
For the purposes of this document, the following terms, definitions, symbols, abbreviations
and conventions 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 DL-address [7498-3]
3.1.2 DL-address-mapping [7498-1]
3.1.3 called-DL-address [7498-3]
3.1.4 calling-DL-address [7498-3]
3.1.5 centralized multi-end-point-connection [7498-1]
3.1.6 DL-connection [7498-1]
3.1.7 DL-connection-end-point [7498-1]
3.1.8 DL-connection-end-point-identifier [7498-1]
3.1.9 DL-connection-mode transmission [7498-1]
3.1.10 DL-connectionless-mode transmission [7498-1]
3.1.11 correspondent (N)-entities [7498-1]
correspondent DL-entities  (N=2)
correspondent Ph-entities  (N=1)

61158-3-11 © IEC:2007 – 9 –
3.1.12 DL-duplex-transmission [7498-1]
3.1.13 (N)-entity [7498-1]
DL-entity  (N=2)
Ph-entity  (N=1)
3.1.14 DL-facility [7498-1]
3.1.15 flow control [7498-1]
3.1.16 (N)-layer [7498-1]
DL-layer  (N=2)
Ph-layer  (N=1)
3.1.17 layer-management [7498-1]
3.1.18 DL-local-view [7498-3]
3.1.19 DL-name [7498-3]
3.1.20 naming-(addressing)-domain [7498-3]
3.1.21 peer-entities [7498-1]
3.1.22 primitive name [7498-3]
3.1.23 DL-protocol [7498-1]
3.1.24 DL-protocol-connection-identifier [7498-1]
3.1.25 DL-protocol-data-unit [7498-1]
3.1.26 DL-relay [7498-1]
3.1.27 reset [7498-1]
3.1.28 responding-DL-address [7498-3]
3.1.29 routing [7498-1]
3.1.30 segmenting [7498-1]
3.1.31 (N)-service [7498-1]
DL-service  (N=2)
Ph-service  (N=1)
3.1.32 (N)-service-access-point [7498-1]
DL-service-access-point  (N=2)
Ph-service-access-point  (N=1)
3.1.33 DL-service-access-point-address [7498-3]
3.1.34 DL-service-connection-identifier [7498-1]
3.1.35 DL-service-data-unit [7498-1]
3.1.36 DL-simplex-transmission [7498-1]
3.1.37 DL-subsystem [7498-1]
3.1.38 systems-management [7498-1]
3.1.39 DLS-user-data [7498-1]
– 10 – 61158-3-11 © IEC:2007
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
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 DLS-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 Data-link service terms and definitions
3.3.1
common memory
virtual common memory over the Type 11 fieldbus, which is shared by the nodes participating
in the Type 11 fielbus and is primarily used for the real-time communications by the TCC data
service
3.3.2
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
61158-3-11 © IEC:2007 – 11 –
3.3.3
DLCEP-address
DL-address which designates either
a) one peer DL-connection-end-point, or
b) one multi-peer publisher DL-connection-end-point and implicitly the corresponding set of
subscriber DL-connection-end-points where each DL-connection-end-point exists within a
distinct DLSAP and is associated with a corresponding distinct DLSAP-address
3.3.4
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.

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
3.3.5
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.
3.3.6
(individual) DLSAP-address
DL-address that designates only one DLSAP within the extended link

– 12 – 61158-3-11 © IEC:2007
NOTE A single DL-entity may have multiple DLSAP-addresses associated with a single DLSAP.
3.3.7
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.
3.3.8
frame
denigrated synonym for DLPDU
3.3.9
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
3.3.10
high-speed cyclic data
RTE data conveyed by means of the high-speed cyclic data transmission
3.3.11
high-speed cyclic data transmission
one of three levels of the TCC data service with the highest priority level
3.3.12
low-speed cyclic data
RTE data conveyed by means of the low-speed cyclic data transmission
3.3.13
low-speed cyclic data transmission
one of three levels of the TCC data service with the lowest priority level
3.3.14
medium-speed cyclic data
RTE data conveyed by means of the medium-speed cyclic data transmission
3.3.15
medium-speed cyclic data transmission
one of three levels of the TCC data service with the second priority level
3.3.16
multipoint connection
connection from one node to many nodes. Multipoint connection allows data transfer from a
single publisher to many subscriber nodes
3.3.17
multi-peer DLC
centralized multi-end-point DL-connection offering DL-duplex-transmission between a single
distinguished DLS-user known as the publisher or publishing DLS-user, and a set of peer but
undistinguished DLS-users known collectively as the subscribers or subscribing DLS-users,
where the publishing DLS-user can send to the subscribing DLS-users as a group (but not

61158-3-11 © IEC:2007 – 13 –
individually), and the subscribing DLS-users can send to the publishing DLS-user (but not to
each other).
3.3.18
node
single DL-entity as it appears on one local link
3.3.19
node-id
two-octet primary identifier for the DLE on the local link, whose values are constrained
NOTE A permissible value is from 1 to 255. A value 0 is specifically used for the SYN node, which emits the SYN
frame.
3.3.20
receiving DLS-user
DL-service user that acts as a recipient of DLS-user-data
NOTE A DL-service user can be concurrently both a sending and receiving DLS-user.
3.3.21
sending DLS-user
DL-service user that acts as a source of DLS-user-data
3.3.22
SYN node
node transmitting the SYN frame
3.3.23
sporadic message data service
aperiodic message transfer which sporadically occurs upon DLS-user requesting one or more
message to transfer, and regular ISO/IEC 8802-3 Ethernet message frame is transferred by
means of this message transfer
3.3.24
TCC data service
cyclic data transfer with three levels of the data transmission at the same time, of which each
data transmission level is according to the data priority and the data transmission period for
real-time delivery, and of which the data transmission period and the total data volume for
each level can be specified in designing phase and on application needs
3.4 Symbols and abbreviations
3.4.1 CM Common memory
3.4.2 DL-
Data-link layer (as a prefix)
3.4.3 DLC DL-connection
3.4.4 DLCEP
DL-connection-end-point
3.4.5 DLE DL-entity (the local active instance of the data-link layer)
3.4.6 DLL
DL-layer
3.4.7 DLPCI DL-protocol-control-information
3.4.8 DLPDU
DL-protocol-data-unit
3.4.9 DLM DL-management
– 14 – 61158-3-11 © IEC:2007
3.4.10 DLME DL-management entity (the local active instance of
DL-management)
3.4.11 DLMS DL-management service
3.4.12 DLS DL-service
3.4.13 DLSAP DL-service-access-point
3.4.14 DLSDU DL-service-data-unit
3.4.15 FIFO First-in first-out (queuing method)
3.4.16 GCM Global common memory
3.4.17 OSI Open systems interconnection
3.4.18 Ph- Physical layer (as a prefix)
3.4.19 PhE Ph-entity (the local active instance of the physical layer)
3.4.20 PhL Ph-layer
3.4.21 QoS Quality of service
3.4.22 RTE Real Time Ethernet
3.4.23 TCC Time-critical cyclic

3.5 Common conventions
This standard 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 standard 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 standard. 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:
a) the request primitive’s input parameters;
b) the request primitive’s output parameters;
c) the indication primitive’s output parameters;
d) the response primitive’s input parameters; and
e) 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: mandatory for the primitive.

61158-3-11 © IEC:2007 – 15 –
U Parameter: a user option which may or may not be provided 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.
(Blank) Parameter is never present.
Some entries are further qualified by items in brackets. These may be
a) 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.
b) an indication that some note applies to the entry
(n) indicates that the following note n contains additional information pertaining to
the parameter and its use.
In any particular interface, not all parameters need be explicitly stated. Some may be
implicitly associated with the DLSAP at which the primitive is issued.
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.
4 Data-link service and concept
4.1 Overview
4.1.1 General
This standard specifies the Type 11 data-link services for a ISO/IEC 8802-3-based time-
critical control network, which is one of the communication networks for Real-Time Ethernet
(RTE) defined in IEC 61784-2.
This standard meets the industrial automation market objective of providing predictable time
deterministic and reliable time-critical data transfer and means, which allow co-existence with
non-time-critical data transfer over the ISO/IEC 8802-3 series communications medium, for
support of cooperation and synchronization between automation processes on field devices in
a real-time application system. 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.
4.1.2 Field of applications
In industrial control systems, several kinds of field devices such as drives, sensors and
actuators, programmable controllers, distributed control systems (DCS) and human machine
interface (HMI) devices are required to be connected with control networks. The process
control data and the state data is transferred among these field devices in the system and the
communications between these field devices requires simplicity in application programming
and to be executed with adequate response time. In most industrial automation systems such
as food, water, sewage, paper and steel, including a rolling mill, the control network is
required to provide time-critical response capability for their application, as required in
ISO/TR 13283 for time-critical communications architectures.

– 16 – 61158-3-11 © IEC:2007
Plant production may be compromised due to errors, which could be introduced to the control
system if the network does not provide a time-critical response. Therefore, the following
characteristics are required for a time-critical control network:
– deterministic response time between the control device nodes;
– ability to share process data seamlessly across the control system.
These services are applicable to such an industrial automation environment, in which time-
critical communications is primarily required. 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.
4.2 General description of services
4.2.1 General
The DLS provides for transparent and reliable transfer of data between DLS-users over a
Type 11 fieldbus. The DLS is base on services provided by the physical layer of
ISO/IEC 8802-3 to the conceptual interface between the physical and data-link layers.
Two types of data transmission services are provided.
a) TCC data service: The connection-oriented buffer transfers between pre-established
point-to-multipoint DLCEPs on the same local link.
b) Sporadic message data service: The unacknowledged connectionless message
transfers between single DLSAPs, or unacknowledged connectionless message transfer
from a single DLSAP to a group of DLSAPs on the extended link.
NOTE For the purpose of clarity, the expressions "buffer transfer" and "message transfer" are used to distinguish
between the two types of communications services, connection-oriented and connectionless, respectively, that are
offered by this DLS,
The buffer transfer service or the TCC data service is based on cyclic data transfers of three
kinds of transmission period. The transmission periods and the total volumes of each level of
the buffer transfer by the multiple distributed DLS-providers on the same local link are defined
when the system is configured, and are based on application needs. Cyclic data transfers are
automatically triggered by the communications system without the user requesting them.
There are also three types of TCC data service according to the transmission period.
a) High-speed cyclic data transmission.
b) Medium-speed cyclic data transmission.
c) Low-speed cyclic data transmission.
The message transfer service or the sporadic message data service is based on aperiodic
data transfer, sporadically occurred upon DLS-user requesting one or more message to
transfer. The priority level and the target token rotation time, corresponding to the target time
to obtain the transmission right to send out the message data on the medium, are defined
when the system is configured, and are based on application needs. The transmit delay is
depending on the priority level and the target token rotation time. Regular ISO/IEC 8802-3
Ethernet message frame is transferred by means of this message transfer service.
The DLS provides DLS-users with a means to set up a quality of service for the transfer of
data. QoS is specified by means of QoS parameters representing aspects such as data
transmit delay, priority level, DLCEP data length, and so on. A DL-management Service
(DLMS) is defined in Clause 5.

61158-3-11 © IEC:2007 – 17 –
4.2.2 Overview of the Data frames flow on the medium
Overview of the data frames flow on the medium is shown in Figure 2 and Figure 3.
The DLL provides the opportunity of transferring data to each node in a sequential order and
within a predetermined time period. At the start time of every high-speed-transmission-period
(Tsyn), the SYN frame is broadcast to all Type 11 fieldbus nodes. When the SYN frame has
been received, the node with sequential number 1 (node 1) starts sending its data frames,
and after the completion of its data frames transmission node 2 can send out its data frames.
The Nth node (node N) can obtain the transmission right after the (N-1) th node completes its
data frames transmission. The sequential number is assigned to each node at the time
approval to join the Type 11 fieldbus is granted, and is up to 255.
Each node can hold the transmission right for a preset time before transfering the
transmission right to the next node. The data to be sent and the data to be retained are
determined by priority.
Data transmission includes cyclic data and sporadic message transmission. Cyclic data
transmission is divided into high, medium and low-speed cyclic data transmission. Each node
sends the high-speed cyclic data frames on each occasion when it obtains the transmission
right. The data of lower priorities, that is the medium-speed cyclic data, the sporadic message
data and the low-speed cyclic data respectively, are sent or not sent depending on the
circumstances.
Time
SYN frame SYN frame
High-speed transmission period
(Tsyn)
Node 1 Node 2 Node 3 Node n Node 1 Node 2
4 priority levels
High-speed
cyclic data
Medium-speed
cyclic data
Sporadic
message data
Low-speed
cyclic data
Figure 2 – Overall flow of data frames during one minimum cycle period
(high-speed transmission period)
The holding time of the transmission right of each node is determined by the settings of the
high-speed cyclic, the medium-speed cyclic, the sporadic message and the low-speed cyclic
data transmission periods and by the volume of transmission data for each node. After
sending all the high-speed cyclic data, the node sends the medium-speed cyclic data. If the
holding time of the transmission right ends during sending the medium-speed cyclic data, the
transmission of the medium-speed cyclic data is interrupted. Node N obtains the transmission
right again during the next high-speed transmission period, during which time all the high-
speed cyclic data and the remainder of the previous medium-speed cyclic data is sent. For the
low-speed cyclic data are sent out in this fashion.

– 18 – 61158-3-11 © IEC:2007
SYN frame
Node N
Th
High-speed
Cyclic data
Tm
Medium-speed
Cyclic data
Tl
Low-speed
Cyclic data
Th: High-speed transmission period(1 Cycle period)
Tm: Medium-speed transmission period (1 Cycle period)
Tl:  Low-speed transmission period (1 Cycle period)

Figure 3 – Overall flow of cyclic data frames over one maximum cycle period
(low-speed transmission period)
4.2.3 Sequence of primitives
A request primitive is used by a DLS-user to request a service. A confirm primitive is returned
to the DLS-user upon completion of the service. Moreover, an indication primitive is used to
report to the DLS-user the receipt of new DLS-user data or the receipt of a new message.
4.2.3.1 Primitives of the TCC data service
The sequence of primitives for the TCC data service is shown in Figure 4.
DL-Data-req indication primitive informs the DLS-user initiates the data transfer using DL-Put
service from the corresponding DLS-user buffer associated with a specified DLCEP to the
send buffer of local DLE for publishing the data.
DL-Put request primitive which responds to DL-Data-req indication primitive allows the DLS-
user to transfer data of the corresponding DLS-user buffer associated with a sp
...