EN 61158-3-22:2014

SLOVENSKI STANDARD
01-marec-2015
Industrijska komunikacijska omrežja - Specifikacije za procesna vodila - 3-22. del:
Specifikacija protokola na ravni podatkovnih povezav - Elementi tipa 22 (IEC 61158
-3-22:2014)
Industrial communication networks - Fieldbus specifications - Part 3-22: Data-link layer
service definition - Type 22 elements (IEC 61158-3-22:2014)
Industrielle Kommunikationsnetze - Feldbusse - Teil 3-22: Dienstfestlegungen des Data
Link Layer (Sicherungsschicht) - Typ 22-Elemente (IEC 61158-3-22:2014)
Réseaux de communication industriels - Spécifications des bus de terrain - Partie 3-22:
Définition des services de la couche liaison de données - Eléments de type 22 (CEI
61158-3-22:2014)
Ta slovenski standard je istoveten z: EN 61158-3-22:2014
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
35.100.20 Podatkovni povezovalni sloj Data link layer
35.110 Omreževanje Networking
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 61158-3-22

NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2014
ICS 25.040.40; 35.100.20; 35.110 Supersedes EN 61158-3-22:2012
English Version
Industrial communication networks - Fieldbus specifications -
Part 3-22: Data-link layer service definition - Type 22 elements
(IEC 61158-3-22:2014)
Réseaux de communication industriels - Spécifications des Industrielle Kommunikationsnetze - Feldbusse - Teil 3-22:
bus de terrain - Partie 3-22: Définition des services de la Dienstfestlegungen des Data Link Layer
couche liaison de données - Eléments de type 22 (Sicherungsschicht) - Typ 22-Elemente
(CEI 61158-3-22:2014) (IEC 61158-3-22:2014)
This European Standard was approved by CENELEC on 2014-09-17. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61158-3-22:2014 E
Foreword
The text of document 65C/759/FDIS, future edition 2 of IEC 61158-3-22, prepared by SC 65C
"Industrial networks" of IEC/TC 65 "Industrial-process measurement, control and automation" was
submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61158-3-22:2014.
The following dates are fixed:
(dop) 2015-06-17
• latest date by which the document has to be implemented at
national level by publication of an identical national
standard or by endorsement
(dow) 2017-09-17
• latest date by which the national standards conflicting with
the document have to be withdrawn

This document supersedes EN 61158-3-22:2012.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association.
Endorsement notice
The text of the International Standard IEC 61158-3-22:2014 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 61158-4-22 NOTE Harmonized as EN 61158-4-22.
IEC 61784-1 NOTE Harmonized as EN 61784-1.
IEC 61784-2 NOTE Harmonized as EN 61784-2.

- 3 - EN 61158-3-22:2014
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is
available here: www.cenelec.eu.

Publication Year Title EN/HD Year
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 2000 Information technology - - -
Telecommunications and information
exchange between systems - Local and
metropolitan area networks - Specific
requirements -
Part 3: Carrier sense multiple access with
collision detection (CSMA/CD) access
method and physical layer specifications
ISO/IEC 10731 -  Information technology - Open Systems - -
Interconnection - Basic Reference Model -
Conventions for the definition of OSI
services
IEEE 802.1D 2004 IEEE Standard for local and metropolitan - -
area networks - Media Access Control
(MAC) Bridges
IETF RFC 791 -  Internet Protocol - -

IEC 61158-3-22 ®
Edition 2.0 2014-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial communication networks – Fieldbus specifications –

Part 3-22: Data-link layer service definition – Type 22 elements

Réseaux de communication industriels – Spécifications des bus de terrain –

Partie 3-22: Définition des services de la couche liaison de données – Éléments

de type 22
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX W
ICS 25.040.40; 35.100.20; 35.110 ISBN 978-2-8322-1718-4

– 2 – IEC 61158-3-22:2014 © IEC 2014
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
1.1 General . 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 . 11
3.4 Symbols and abbreviations . 13
3.5 Common conventions . 15
4 Data-link layer services and concepts . 16
4.1 Operating principle . 16
4.2 Communication models . 16
4.3 Topology . 18
4.4 Addressing . 19
4.5 Gateway . 20
4.6 Interaction models . 20
4.7 Synchronization concept . 20
5 Communication services . 21
5.1 Overview . 21
5.2 Communication management services . 23
5.3 Cyclic data channel service (CDC) . 30
5.4 Message channel services (MSC) . 30
5.5 Time synchronization . 32
5.6 Media independent interface (MII) management services . 34
Bibliography . 36

Figure 1 – RTFL device reference model . 17
Figure 2 – RTFN device reference model . 18
Figure 3 – Logical double line in a physical tree topology. 18
Figure 4 – Logical double line in a physical line topology . 19
Figure 5 – Addressing modes . 19
Figure 6 – Time sequence diagram for time SYNC_START service . 21
Figure 7 – Synchronized timing signals without offset . 21
Figure 8 – Synchronized timing signals with offset . 21

Table 1 – Summary of DL-services and primitives . 22
Table 2 – DL-Network verification service (NV) . 23
Table 3 – DL-RTFN scan network read service (RTFNSNR) . 23

IEC 61158-3-22:2014 © IEC 2014 – 3 –
Table 4 – DL-RTFN connection establishment DLL service (RTFNCE) . 24
Table 5 – DL-RTFN connection release service (RTFNCR) . 24
Table 6 – DL-RTFL control service (RTFLCTL) . 25
Table 7 – DL-RTFL configuration service (RTFLCFG) . 25
Table 8 – DL-Read configuration data service (RDCD) . 26
Table 9 – DL-RTFL configuration service 2 (RTFLCFG2) . 28
Table 10 – DL-Read configuration data service 2 (RDCD2) . 29
Table 11 – CDC send service (CDCS) . 30
Table 12 – MSC send service (MSCS) . 31
Table 13 – MSC send broadcast service (MSCSB) . 31
Table 14 – MSC read service (MSCR) . 32
Table 15 – DL-DelayMeasurement start service (DMS) . 32
Table 16 – DL-DelayMeasurement read service (DMR) . 32
Table 17 – DL-PCS configuration service (PCSC) . 33
Table 18 – DL-Sync master configuration service (SYNC_MC) . 33
Table 19 – DL-Sync start service (SYNC_START) . 34
Table 20 – DL-Sync stop service (SYNC_STOP). 34
Table 21 – DL-MII read service (MIIR) . 35
Table 22 – DL-MII write service (MIIW) . 35

– 4 – IEC 61158-3-22:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-22: Data-link layer service definition –
Type 22 elements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as
“IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee
interested in the subject dealt with may participate in this preparatory work. International, governmental and
non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates
closely with the International Organization for Standardization (ISO) in accordance with conditions determined
by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of
IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other
IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
Attention is drawn to the fact that the use of the associated protocol type is restricted by its
intellectual-property-right holders. In all cases, the commitment to limited release of
intellectual-property-rights made by the holders of those rights permits a layer protocol type to
be used with other layer protocols of the same type, or in other type combinations explicitly
authorized by its intellectual-property-right holders.
NOTE Combinations of protocol types are specified in IEC 61784-1 and IEC 61784-2.
International Standard IEC 61158-3-22 has been prepared by subcommittee 65C: Industrial
networks, of IEC technical committee 65: Industrial process measurement, control and
automation.
This second edition cancels and replaces the first edition published in 2010. This edition
constitutes a technical revision. This edition includes the following technical changes with
respect to the previous edition.
• Introduction of two new topology scan services.
• Marking old topology scan services as to be discontinued.

IEC 61158-3-22:2014 © IEC 2014 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
65C/759/FDIS 65C/769/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 61158 series, published under the general title Industrial
communication networks – Fieldbus specifications, can be found on the IEC web site.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be:
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 61158-3-22:2014 © IEC 2014
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 standard is a conceptual architectural service,
independent of administrative and implementation divisions.
The International Electrotechnical Commission (IEC) draws attention to the fact that it is
claimed that compliance with this document may involve the use of patents concerning
Type 22 elements and possibly other types:
WO-2006/069691 A1 [PI] Control system with a plurality of spatially distributed stations
and method for transmitting data in said control system
DE-10 2004 063 213 [PI] Steuerungssystem mit einer Vielzahl von räumlich verteilten
B4 Stationen sowie Verfahren zum Übertragen von Daten in einem
solchen Steuerungssystem
EP-1 828 858 A1 [PI] Control system with a plurality of spatially distributed stations
and method for transmitting data in said control system
JP-4 848 469 B2 [PI] Control system with a plurality of spatially distributed stations
and method for transmitting data in said control system
CN-101 111 807 [PI] Control system with a plurality of spatially distributed stations
and method for transmitting data in said control system
US-8 144 718 B2 [PI] Control system having a plurality of spatially distributed stations,
and method for transmitting data in such a control system
IEC takes no position concerning the evidence, validity and scope of these patent rights.
The holders of these patent rights have assured IEC that they are willing to negotiate licenses
either free of charge or under reasonable and non-discriminatory terms and conditions with
applicants throughout the world. In this respect, the statement of the holders of these patent
rights is registered with IEC. Information may be obtained from:
[PI] Pilz GmbH & Co. KG
Felix-Wankel-Str. 2
73760 Ostfildern
Germany
Attention is drawn to the possibility that some of the elements of this document may be the
subject of patent rights other than those identified above. IEC shall not be held responsible for
identifying any or all such patent rights.
ISO (www.iso.org/patents) and IEC (http://patents.iec.ch) maintain on-line data bases of
patents relevant to their standards. Users are encouraged to consult the data bases for the
most up to date information concerning patents.

IEC 61158-3-22:2014 © IEC 2014 – 7 –
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-22: Data-link layer service definition –
Type 22 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 standard defines in an abstract way the externally visible service provided by the
Type 22 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 22 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 does 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 fulfils the Type 22 data-link layer services defined in this standard.

– 8 – IEC 61158-3-22:2014 © IEC 2014
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
NOTE All parts of the IEC 61158 series, as well as IEC 61784-1 and IEC 61784-2 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 8802-3:2000, Information technology – Telecommunications and information
exchange between systems – Local and metropolitan area networks – Specific requirements –
Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and
physical layer specifications
ISO/IEC 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
IEEE 802.1D-2004, IEEE Standard for Local and metropolitan area networks – Media Access
Control (MAC) Bridges, available at http://www.ieee.org
IETF RFC 791, Internet protocol, available at
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:
DL-address [ISO/IEC 7498-3]
called-DL-address [ISO/IEC 7498-3]
calling-DL-address [ISO/IEC 7498-3]
DL-connection [ISO/IEC 7498-1]
DL-connection-end-point [ISO/IEC 7498-1]
DL-connection-end-point-identifier [ISO/IEC 7498-1]
DL-connection-mode transmission [ISO/IEC 7498-1]
DL-connectionless-mode transmission [ISO/IEC 7498-1]

IEC 61158-3-22:2014 © IEC 2014 – 9 –
correspondent (N)-entities [ISO/IEC 7498-1]
correspondent DL-entities (N=2)
correspondent Ph-entities (N=1)
decentralized multi-end-point-connection [ISO/IEC 7498-1]
DL-duplex-transmission [ISO/IEC 7498-1]
(N)-entity [ISO/IEC 7498-1]
DL-entity (N=2)
Ph-entity (N=1)
DL-facility [ISO/IEC 7498-1]
flow control [ISO/IEC 7498-1]
(N)-layer [ISO/IEC 7498-1]
DL-layer (N=2)
Ph-layer (N=1)
layer-management [ISO/IEC 7498-1]
DL-local-view [ISO/IEC 7498-3]
multi-endpoint-connection [ISO/IEC 7498-1]
DL-name [ISO/IEC 7498-3]
naming-(addressing)-domain [ISO/IEC 7498-3]
peer-entities [ISO/IEC 7498-1]
primitive name [ISO/IEC 7498-3]
DL-protocol [ISO/IEC 7498-1]
DL-protocol-connection-identifier [ISO/IEC 7498-1]
DL-protocol-data-unit [ISO/IEC 7498-1]
DL-relay [ISO/IEC 7498-1]
reassembling [ISO/IEC 7498-1]
reset [ISO/IEC 7498-1]
responding-DL-address [ISO/IEC 7498-3]
routing [ISO/IEC 7498-1]
segmenting [ISO/IEC 7498-1]
(N)-service [ISO/IEC 7498-1]
DL-service (N=2)
– 10 – IEC 61158-3-22:2014 © IEC 2014
Ph-service (N=1)
(N)-service-access-point [ISO/IEC 7498-1]
DL-service-access-point (N=2)
Ph-service-access-point (N=1)
DL-service-access-point-address [ISO/IEC 7498-3]
DL-service-connection-identifier [ISO/IEC 7498-1]
DL-service-data-unit [ISO/IEC 7498-1]
DL-simplex-transmission [ISO/IEC 7498-1]
DL-subsystem [ISO/IEC 7498-1]
systems-management [ISO/IEC 7498-1]
DL-user-data [ISO/IEC 7498-1]
3.2 Service convention terms and definitions
This standard also makes use of the following terms defined in ISO/IEC 10731 as they apply
to the data-link layer:
acceptor
asymmetrical service
confirm (primitive);
requestor.deliver (primitive)
deliver (primitive)
DL-confirmed-facility
DL-facility
DL-local-view
DL-mandatory-facility
DL-non-confirmed-facility
DL-provider-initiated-facility
DL-provider-optional-facility
DL-service-primitive;
primitive
DL-service-provider
DL-service-user
DL-user-optional-facility
indication (primitive);
acceptor.deliver (primitive)
multi-peer
request (primitive);
requestor.submit (primitive)
requestor
response (primitive);
IEC 61158-3-22:2014 © IEC 2014 – 11 –
acceptor.submit (primitive)
submit (primitive)
symmetrical service
3.3 Data-link service terms and definitions
3.3.1
acyclic data
data which is transferred from time to time for dedicated purposes
3.3.2
cell
synonym for a single DL-segment which uses RTFL communication model
3.3.3
communication cycle
fixed time period between which the root device issues empty frames for cyclic
communication initiation in which data is transmitted utilizing CDC and MSC
3.3.4
cycle time
duration of a communication cycle
3.3.5
cyclic
events which repeat in a regular and repetitive manner
3.3.6
cyclic communication
periodic exchange of frames
3.3.7
cyclic data
data which is transferred in a regular and repetitive manner for dedicated purposes
3.3.8
cyclic data channel
CDC
one or more frames, which are reserved for cyclic data
3.3.9
data
generic term used to refer to any information carried over a fieldbus
3.3.10
device
physical entity connected to the fieldbus
3.3.11
DL-segment
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
– 12 – IEC 61158-3-22:2014 © IEC 2014
3.3.12
error
discrepancy between a computed, observed or measured value or condition and the specified
or theoretically correct value or condition
3.3.13
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 1 to entry: An extended link may be composed of just a single link.
3.3.14
frame
denigrated synonym for DLPDU
3.3.15
gateway
device acting as a linking element between different protocols
3.3.16
interface
shared boundary between two functional units, defined by functional characteristics, signal
characteristics, or other characteristics as appropriate
3.3.17
link
synonym for DL-segment
3.3.18
logical double line
sequence of root device and all ordinary devices processing the communication frame in
forward and backward direction
3.3.19
master clock
global time base for the PCS mechanism
3.3.20
message
ordered sequence of octets intended to convey data
3.3.21
message channel
MSC
one or more DPUs (frames), which are reserved for acyclic data
3.3.22
network
set of devices connected by some type of communication medium, including any intervening
repeaters, bridges, routers and lower-layer gateways
3.3.23
open network
any network based on IEC 8802-3 with no further restrictions

IEC 61158-3-22:2014 © IEC 2014 – 13 –
3.3.24
ordinary device
OD
slave in the communication system, which utilizes RTFL for cyclic and acyclic data
interchange with other ODs in the same logical double line
3.3.25
precise clock synchronization
PCS
mechanism to synchronize clocks of RTFL devices and maintain a global time base
3.3.26
process data
data designated to be transferred cyclically or acyclically for the purpose of processing
3.3.27
protocol
convention about the data formats, time sequences, and error correction in the data exchange
of communication systems
3.3.28
root device
RD
master in the communication system, which organises, initiates and controls the RTFL cyclic
and acyclic data interchange for one logical double line
3.3.29
real time frame line
RTFL
communication model communicating in a logical double line
3.3.30
real time frame network
RTFN
communication model communicating in a switched network
3.3.31
switch
MAC bridge as defined in IEEE 802.1D
3.3.32
timing signal
time-based indication of the occurrence of an event, commonly as an interrupt signal, used for
DL-user synchronization
3.3.33
topology
physical network architecture with respect to the connection between the stations of the
communication system
3.4 Symbols and abbreviations
CDC Cyclic data channel
CDCS Cyclic data channel send
DA Device address
– 14 – IEC 61158-3-22:2014 © IEC 2014
DL- Data-link layer (as a prefix)
DLL DL-layer
DLS DL-service
DMR DL-DelayMeasurement read
DMS DL-DelayMeasurement send
ID Identification
IP Internet protocol
IRQ Interrupt request
MAC Medium access control
MII Media independent interface
MIIR DL-Media independent interface read
MIIW DL-Media independent interface write
MSC Message channel
MSCDN Message channel data notification
MSCR Message channel read
MSCS Message channel send
MSCSB Message channel send broadcast
NV DL-Network verification
OD Ordinary device
OSI Open systems interconnection
PID Packet ID
PCS Precise clock synchronization
PCSC DL-PCS configuration
RD Root device
RDCD DL-Read configuration data
RTF Real time frame
IEC 61158-3-22:2014 © IEC 2014 – 15 –
RTFL Real time frame line
RTFLCFG DL-RTFL configuration
RTFLCTL DL-RTFL control
RTFN Real time frame network
RTFNCE DL-RTFN connection establishment
RTFNCR DL-RTFN connection release
RTFNSNR DL-RTFN Scan network read
SYNC Synchronization
SYNC_MC DL-Sync master configuration
SYNC_START DL-Sync start
SYNC_STOP DL-Sync stop
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:
• the request primitive’s input parameters;
• the request primitive’s output 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.

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U parameter is a User option, and 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 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 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.
4 Data-link layer services and concepts
4.1 Operating principle
Type 22 of this series of international standards describes a technology for ISO/IEC 8802-3
based networks which was developed to meet the requirements of automation technology. For
the purpose of fast intra-machine communication Type 22 describes a communication model
(RTFL) for fast real-time communication. Furthermore, networking of several parts of an
automation system into an overall system is supported by the specification of a second
communication model (RTFN). Type 22 is designed as a multi-master bus system to enable
networking of individual control systems in a distributed automation solution.
A Type 22 network utilizes standard ISO/IEC 8802-3 DPUs (frames) for both communication
models.
4.2 Communication models
4.2.1 Overview
Type 22 technology essentially specifies two communication models. RTFL communication is
intended for fast machine communication while RTFN provides for the networking of individual
machines or cells.
For RTFL communication model, communication follows a line topology. RTFL communication
is based on cyclic data transfer in an ISO/IEC 8802-3 DLPDU . This basic cyclic data transfer
is provided by a special device, the root device (RD). Root devices act as communication
master to cyclically initiate communication. The DLPDUs originated by the root device are
passed to the Type 22 ordinary devices (OD). Each ordinary device receives the frame, writes
its data and passes the frame on. A RTFL network requires exactly one root device. The last
ordinary device of a RTFL network sends the processed frame back. The frame is transferred
back in reverse device order to the root device so that it is returned by the first ordinary
device to the root device as response frame. In backward direction, the ordinary devices read
their relevant data from the frame.

IEC 61158-3-22:2014 © IEC 2014 – 17 –
For RTFN communication model, communication is based on individual point to point
connections between participating devices.
4.2.2 RTFL device reference model
Type 22 services are described using the principles, methodology and model of
ISO/IEC 7498-1 (OSI). The OSI model provides a layered approach to communications
standards, whereby the layers can be developed and modified independently. The Type 22
specification defines functionality from top to bottom of a full OSI model. Functions of the
intermediate OSI layers, layers 3 to 6, are consolidated into either the Type 22 data-link layer
or the DL-user. The device reference model for a Type 22 RTFL device is shown in Figure 1.
Layer
management
DL-user
Message Cyclic
channel data
Clock
channel
synchronization
DLL
DLL configuration
RTF processor
Communication
MAC
management
Physical layer
Figure 1 – RTFL device reference model
4.2.3 RTFN device reference model
Type 22 services are described using the principles, methodology and model of
ISO/IEC 7498-1 (OSI). The OSI model provides a layered approach to communications
standards, whereby the layers can be developed and modified independently. The Type 22
specification defines functionality from top to bottom of a full OSI model. Functions of the
intermediate OSI layers, layers 3 to 6, are consolidated into either the Type 22 data-link layer
or the DL-user. The device reference model for a Type 22 RTFN device is shown in Figure 2.

– 18 – IEC 61158-3-22:2014 © IEC 2014
Layer
management
DL-user
Cyclic Message Clock
data channel synchronization
channel
DLL
UDP/IP
Communication
MAC
management
Physical layer
Figure 2 – RTFN device reference model
4.3 Topology
4.3.1 RTFL topology
A Type 22 network utilizing the RTFL communication model uses a logical double line
topology. A logical double line is represented by the arrangement of all ordinary devices and
the root device and the DLPDU processing in forward and backward direction. Data transfer is
handled by DLPDU transfer from one device to the next device along the logical double line.
The last ordinary device returns the frame back to the root device along all participating
ordinary devices
A logical double line is able to allow different network topologies. In a switch operated tree
structure each ordinary device has a predecessor and a successor device although they are
not physically located in a sequence. This is shown in Figure 3.
Logical double line
Root Ordinary Ordinary Ordinary Ordinary
device device device device device

Switch
Figure 3 – Logical double line in a physical tree topology
The ordinary devices for the RTFL communication model should provide two ISO/IEC 8802-.3
based communication interfaces. This allows set-up of a physical line structure as shown in

IEC 61158-3-22:2014 © IEC 2014 – 19 –
Figure 4. If the ordinary devices are arranged in a physical line DLPDUs shall be directly
forwarded from one interface to the next interface and processed on-the-fly (cut-through).
Logical double line
Root Ordinary Ordinary
Ordinary Ordinary
device device device
device device
Figure 4 – Logical double line in a physical line topology
For a Type 22 network utilizing the RTFL communication model the frame pump concept is
specified. This concept shall be applied by the root devic
...