Industrial communication networks - Fieldbus specifications - Part 5-19: Application layer service definition - Type 19 elements

IEC 61158-5-19:2019 defines the services provided to the FAL user at the boundary between the user and the application layer of the fieldbus reference model, and Systems Management at the boundary between the application layer and Systems Management of the fieldbus reference model. This standard specifies the structure and services of the IEC fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545). This fourth edition cancels and replaces the third edition published in 2014 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
• improving the hotplug and redundancy features;
• improving the phase switching and the error handling;
• editorial improvements.

Réseaux de communication industriels - Spécifications des bus de terrain - Partie 5-19: Définition des services de la couche application - Éléments de type 19

L’IEC 61158-5-19:2019 fournit des éléments communs pour les communications de messagerie prioritaires et non prioritaires élémentaires entre les programmes d’application des environnements d’automatisation et le matériel spécifique au bus de terrain de type 19. On utilise le terme "prioritaire" pour traduire la présence d’une fenêtre temporelle, à l’intérieur de laquelle il est exigé de terminer une ou plusieurs actions spécifiées avec un niveau de certitude défini. Si les actions spécifiées ne sont pas réalisées dans la fenêtre temporelle, les applications demandant les actions risquent de connaître une défaillance, avec les risques que cela comporte pour les équipements, les installations et éventuellement la vie humaine.
La présente norme définit de manière abstraite le service visible de l'extérieur fourni par la couche application de bus de terrain en termes
a) d’un modèle abstrait pour la définition des ressources d’application (objets) qui peuvent être manipulées par les utilisateurs par l'intermédiaire de l’utilisation du service FAL,
b) des actions primitives et des événements du service;
c) des paramètres associés à chaque action et événement primitif, et de la forme qu’ils peuvent prendre; et
d) des interrelations entre ces actions et événements, et de leurs séquences valides.

General Information

Status
Published
Publication Date
09-Apr-2019
Technical Committee
Drafting Committee
Current Stage
PPUB - Publication issued
Start Date
10-Apr-2019
Completion Date
26-Apr-2019
Ref Project

Relations

Overview - IEC 61158-5-19:2019 (Type 19 elements)

IEC 61158-5-19:2019 is the IEC international standard that defines the application layer service definition for Type 19 fieldbus elements. It specifies the services provided to the Fieldbus Application Layer (FAL) user at the boundary between the user and the application layer, and the services between the application layer and Systems Management. The standard conforms to the OSI Basic Reference Model (ISO/IEC 7498‑1) and the OSI application layer structure (ISO/IEC 9545). Edition 4.0 (2019) is a technical revision of the 2014 edition and includes improvements to hotplug and redundancy, phase switching, error handling, and editorial clarifications.

Key technical topics and requirements

  • Application layer service model (FAL): Defines how application programs access the fieldbus communication environment and the abstract services offered upward from the application layer.
  • Service definitions and ASEs: Specifies Application Service Elements (ASEs) and data types (bitstrings, unsigned/integer/floating types, structure types) used by Type 19.
  • Communication model: Covers communication mechanisms, IDN concept, ASEs such as Identification and Management (MGT), and Application Relationship (AR) classes.
  • AR roles and AREPs: Describes AR classes and AREP types for point-to-point and publisher/subscriber communication, supporting both confirmed and unconfirmed, time‑critical and non‑time‑critical messaging.
  • Predefined services: Includes service primitives and parameter tables for Read, Write, Notify, Get network/device status, Enable/Disable RTC, hotplug support, and status-change reporting.
  • Conformance: Specifies how implementations demonstrate conformance to the FAL service definitions and interaction with Systems Management.
  • Reliability and availability features: Enhancements in this edition target hotplug, redundancy, phase switching, and error handling for more robust industrial networks.

Practical applications and who uses this standard

  • Device and fieldbus protocol implementers: to build FAL-compliant communication stacks for Type 19 fieldbus devices.
  • Automation system integrators and OEMs: to ensure device interoperability and predictable behavior for time-critical and non‑time‑critical messaging.
  • System architects and network designers: to specify application-layer behavior, hotplug/redundancy strategies, and lifecycle management.
  • Test labs and certification bodies: to develop conformance and interoperability test suites based on the defined services.
  • Maintenance and operations engineers: to understand status reporting, error handling and system-management interactions.

Related standards (for implementation and interoperability)

  • IEC 61158 series (other parts of Fieldbus specifications)
  • IEC 61784‑1 / IEC 61784‑2 (protocol profiles and type combinations)
  • ISO/IEC 7498‑1 and ISO/IEC 9545 (OSI Basic Reference Model and application layer)

Keywords: IEC 61158-5-19, fieldbus, application layer, FAL, Type 19, industrial communication networks, hotplug, redundancy, OSI application layer, fieldbus services, time-critical messaging.

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IEC 61158-5-19:2019 - Industrial communication networks - Fieldbus specifications - Part 5-19: Application layer service definition - Type 19 elements
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Standards Content (Sample)


IEC 61158-5-19 ®
Edition 4.0 2019-04
INTERNATIONAL
STANDARD
Industrial communication networks – Fieldbus specifications –
Part 5-19: Application layer service definition – Type 19 elements

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IEC 61158-5-19 ®
Edition 4.0 2019-04
INTERNATIONAL
STANDARD
Industrial communication networks – Fieldbus specifications –

Part 5-19: Application layer service definition – Type 19 elements

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 25.040.40; 35.100.70; 35.110 ISBN 978-2-8322-6751-6

– 2 – IEC 61158-5-19:2019 © IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
1.1 General . 7
1.2 Specifications . 8
1.3 Conformance . 8
2 Normative references . 8
3 Terms, definitions, symbols, abbreviations and conventions . 9
3.1 ISO/IEC 7498-1 terms . 9
3.2 ISO/IEC 8822 terms . 9
3.3 ISO/IEC 9545 terms . 9
3.4 ISO/IEC 8824-1 terms . 10
3.5 Fieldbus application-layer specific definitions . 10
3.6 Abbreviations and symbols . 12
3.7 Conventions . 12
3.7.1 Overview . 12
3.7.2 General conventions . 12
3.7.3 Conventions for class definitions . 12
3.7.4 Conventions for service definitions . 14
4 Concepts . 15
5 Data type ASE . 15
5.1 Bitstring types . 15
5.1.1 BitString8 . 15
5.1.2 BitString16. 16
5.1.3 BitString32. 16
5.1.4 BitString64. 16
5.2 Unsigned types . 16
5.2.1 Unsigned16 . 16
5.2.2 Unsigned32 . 16
5.2.3 Unsigned64 . 17
5.3 Integer types . 17
5.3.1 Integer16 . 17
5.3.2 Integer32 . 17
5.3.3 Integer64 . 17
5.4 Floating Point types . 17
5.4.1 Float32 . 17
5.4.2 Float64 . 18
5.5 Structure types . 18
5.5.1 STRING2 . 18
6 Communication model specification . 18
6.1 Concepts . 18
6.1.1 Communication mechanisms . 18
6.1.2 IDN concept . 18
6.2 ASEs . 18
6.2.1 Identification number (IDN) ASE . 18
6.2.2 CYCIDN ASE . 21

6.2.3 Management (MGT) ASE . 24
6.3 ARs . 31
6.3.1 General . 31
6.3.2 Point-to-point user-triggered confirmed client/server AREP (SVC) . 31
6.3.3 Point-to-point network-scheduled unconfirmed publisher/subscriber

AREP (RTC-MS) . 31
6.3.4 Point-to-multipoint network-scheduled unconfirmed publisher/subscriber
AREP (RTC-CC) . 32
6.4 Summary of AR classes . 32
6.5 Permitted FAL services by AREP role . 33
Bibliography . 34

Table 1 – Read service parameters. 20
Table 2 – Write service parameters . 21
Table 3 – Read service parameters. 22
Table 4 – Write service parameters . 23
Table 5 – Notify service parameters . 24
Table 6 – Get network status service parameters . 25
Table 7 – Get device status service parameters . 26
Table 8 – Network status change report service parameters . 26
Table 9 – Station status change report service parameters . 27
Table 10 – Set device status service parameters . 27
Table 11 – Enable RTC service parameters . 28
Table 12 – Enable hotplug service parameters . 29
Table 13 – Notify RTC service parameters . 30
Table 14 – Disable RTC service parameters . 30
Table 15 – AREP (SVC) class summary . 32
Table 16 – AREP (RTC-MS) class summary . 32
Table 17 – AREP (RTC-CC) class summary . 33
Table 18 – FAL services by AR type . 33

– 4 – IEC 61158-5-19:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 5-19: Application layer service definition –
Type 19 elements
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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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.
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 61158-5-19 has been prepared by subcommittee 65C: Industrial
networks, of IEC technical committee 65: Industrial-process measurement, control and
automation.
This fourth edition cancels and replaces the third edition published in 2014. This edition
constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous
edition:
• improving the hotplug and redundancy features;
• improving the phase switching and the error handling;
• editorial improvements.
The text of this International Standard is based on the following documents:
FDIS Report on voting
65C/947/FDIS 65C/950/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 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.
A bilingual version of this publication may be issued at a later date.

– 6 – IEC 61158-5-19:2019 © IEC 2019
INTRODUCTION
This document 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.
The application service is provided by the application protocol making use of the services
available from the data-link or other immediately lower layer. This document defines the
application service characteristics that fieldbus applications and/or system management may
exploit.
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 application layer service defined in this document is a conceptual architectural
service, independent of administrative and implementation divisions.

INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 5-19: Application layer service definition –
Type 19 elements
1 Scope
1.1 General
The fieldbus application layer (FAL) provides user programs with a means to access the
fieldbus communication environment. In this respect, the FAL can be viewed as a “window
between corresponding application programs.”
This part of IEC 61158 provides common elements for basic time-critical and non-time-critical
messaging communications between application programs in an automation environment and
material specific to Type 19 fieldbus. 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 International Standard defines in an abstract way the externally visible service provided
by the fieldbus application layer in terms of
a) an abstract model for defining application resources (objects) capable of being
manipulated by users via the use of the FAL service,
b) the primitive actions and events of the service;
c) the parameters associated with each primitive action and event, and the form which they
take; and
d) the interrelationship between these actions and events, and their valid sequences.
The purpose of this document is to define the services provided to
a) the FAL user at the boundary between the user and the application layer of the fieldbus
reference model, and
b) Systems Management at the boundary between the application layer and Systems
Management of the fieldbus reference model.
This document specifies the structure and services of the fieldbus application layer, in
conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application
layer structure (ISO/IEC 9545).
FAL services and protocols are provided by FAL application-entities (AE) contained within the
application processes. The FAL AE is composed of a set of object-oriented application service
elements (ASEs) and a layer management entity (LME) that manages the AE. The ASEs
provide communication services that operate on a set of related application process object
(APO) classes. One of the FAL ASEs is a management ASE that provides a common set of
services for the management of the instances of FAL classes.
Although these services specify, from the perspective of applications, how request and
responses are issued and delivered, they do not include a specification of what the requesting
and responding applications are to do with them. That is, the behavioral aspects of the
applications are not specified; only a definition of what requests and responses they can

– 8 – IEC 61158-5-19:2019 © IEC 2019
send/receive is specified. This permits greater flexibility to the FAL users in standardizing
such object behavior. In addition to these services, some supporting services are also defined
in this document to provide access to the FAL to control certain aspects of its operation.
1.2 Specifications
The principal objective of this document is to specify the characteristics of conceptual
application layer services suitable for time-critical communications, and thus supplement the
OSI Basic Reference Model in guiding the development of application layer protocols for time-
critical communications.
A secondary objective is to provide migration paths from previously-existing industrial
communications protocols. It is this latter objective which gives rise to the diversity of services
standardized as the various Types of IEC 61158, and the corresponding protocols
standardized in subparts of IEC 61158-6.
This specification may be used as the basis for formal application 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 document does not specify individual implementations or products, nor does it constrain
the implementations of application layer entities within industrial automation systems.
There is no conformance of equipment to this application layer service definition standard.
Instead, conformance is achieved through implementation of conforming application layer
protocols that fulfill the application layer services as defined in this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
NOTE All parts of the IEC 61158 series, as well as 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.
IEC 61131-3, Programmable controllers – Part 3: Programming languages
IEC 61158-1:2019, Industrial communication networks – Fieldbus specifications – Part 1:
Overview and guidance for the IEC 61158 and IEC 61784 series
IEC 61158-4-19:2019, Industrial communication networks – Fieldbus specifications –
Part 4-19: Data-link layer protocol specification – Type 19 elements
ISO/IEC 7498-1, Information technology – Open Systems Interconnection – Basic Reference
Model: The Basic Model
ISO/IEC 8822, Information technology – Open Systems Interconnection – Presentation
service definition
ISO/IEC 8824-1, Information technology – Abstract Syntax Notation One (ASN.1):
Specification of basic notation
ISO/IEC 9545, Information technology – Open Systems Interconnection – Application Layer
structure
ISO/IEC 10646, Information technology – Universal Coded Character Set (UCS)
ISO/IEC 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
ISO/IEC/IEEE 60559, Information technology – Microprocessor Systems – Floating-Point
arithmetic
3 Terms, definitions, symbols, abbreviations and conventions
For the purposes of this document, the following terms, definitions, symbols, abbreviations
and conventions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 ISO/IEC 7498-1 terms
For the purposes of this document, the following terms as defined in ISO/IEC 7498-1 apply:
a) application entity
b) application process
c) application protocol data unit
d) application service element
e) application entity invocation
f) application process invocation
g) application transaction
h) real open system
i) transfer syntax
3.2 ISO/IEC 8822 terms
For the purposes of this document, the following terms as defined in ISO/IEC 8822 apply:
a) abstract syntax
b) presentation context
3.3 ISO/IEC 9545 terms
For the purposes of this document, the following terms as defined in ISO/IEC 9545 apply:
a) application-association
b) application-context
c) application context name
d) application-entity-invocation

– 10 – IEC 61158-5-19:2019 © IEC 2019
e) application-entity-type
f) application-process-invocation
g) application-process-type
h) application-service-element
i) application control service element
3.4 ISO/IEC 8824-1 terms
For the purposes of this document, the following terms as defined in ISO/IEC 8824-1 apply:
a) object identifier
b) type
3.5 Fieldbus application-layer specific definitions
3.5.1
coded character set
code
set of unambiguous rules that establish a character set and one-to-one relationship between
the characters of the set and their representation by one or more bit combinations
3.5.2
cross communication
direct data transfer between slave devices (without active involvement of master)
3.5.3
cycle time
duration of a communication cycle
3.5.4
cyclic data
part of a telegram, which does not change its meaning during cyclic operation of the network
3.5.5
device
slave in the communication network
Note 1 to entry: Examples are a power drive system as defined in the IEC 61800-7 (all parts), I/O stations as
defined in IEC 61131 (all parts), etc.
3.5.6
device status
four adjacent octets inside the acknowledge telegram containing status information for each
device
3.5.7
element
part of IDNs
Note 1 to entry: Each IDN has 7 elements, whereas each one has a specific meaning (e.g., number, name, data).
3.5.8
hot plug
possibility to open the communication network and insert or remove slaves while the network
is still in real-time operation

3.5.9
identification number
designation of operating data under which a data block is preserved with its attribute, name,
unit, minimum and maximum input values, and the data
3.5.10
loopback
mode by which a device passes on a received telegram to the same port and to the other port,
either changed or unchanged
3.5.11
master
node which assigns the other nodes (i.e., slaves) the right to transmit
3.5.12
physical layer
first layer of the ISO-OSI reference model
3.5.13
protocol
convention about the data formats, time sequences, and error correction in the data exchange
of communication systems
3.5.14
service channel
SVC
non real-time transmission of information upon master request during RT channel
3.5.15
slave
node which is assigned the right to transmit by the master
3.5.16
station
node
3.5.17
topology
physical network architecture with respect to the connection between the stations of the
communication system
– 12 – IEC 61158-5-19:2019 © IEC 2019
3.6 Abbreviations and symbols
AHS Service transport handshake of the device (acknowledge HS)
AP Application Process
APO Application Object
AR Application Relationship
AREP Application Relationship End Point
ASE Application Service Element
CC-data Cross Communication
Cnf Confirmation
DA Destination address
DAT Duration of acknowledge telegram
FAL Fieldbus Application Layer
ID Identification Number
IDN Identification Number
Ind Indication
MS Master Slave
NRC Non Real Time Channel
NA Not applicable
Req Request
Rsp Response
RTC Real Time Channel
RTE Real Time Ethernet
3.7 Conventions
3.7.1 Overview
The FAL is defined as a set of object-oriented ASEs. Each ASE is specified in a separate
subclause. Each ASE specification is composed of two parts, its class specification, and its
service specification.
The class specification defines the attributes of the class. The attributes are accessible from
instances of the class using the Object Management ASE services specified in Clause 5 of
this document. The service specification defines the services that are provided by the ASE.
3.7.2 General conventions
This document uses the descriptive conventions given in ISO/IEC 10731.
3.7.3 Conventions for class definitions
Class definitions are described using templates. Each template consists of a list of attributes
for the class. The general form of the template is shown below:
FAL ASE: ASE Name
CLASS:  Class name
CLASS ID: #
PARENT CLASS: Parent class name
ATTRIBUTES:
1 (o) Key Attribute: numeric identifier
2 (o) Key Attribute: name
3 (m) Attribute: attribute name(values)
4 (m) Attribute: attribute name(values)

4.1 (s) Attribute: attribute name(values)
4.2 (s) Attribute: attribute name(values)
4.3 (s) Attribute: attribute name(values)
5. (c) Constraint: constraint expression
5.1 (m) Attribute: attribute name(values)
5.2 (o) Attribute: attribute name(values)
6 (m) Attribute: attribute name(values)
6.1 (s) Attribute: attribute name(values)
6.2 (s) Attribute: attribute name(values)
SERVICES:
1 (o) OpsService: service name
2. (c) Constraint: constraint expression
2.1 (o)   OpsService:   service name
3 (m) MgtService: service name

(1) The "FAL ASE:" entry is the name of the FAL ASE that provides the services for the class
being specified.
(2) The "CLASS:" entry is the name of the class being specified. All objects defined using this
template will be an instance of this class. The class may be specified by this document, or
by a user of this document.
(3) The "CLASS ID:" entry is a number that identifies the class being specified. This number is
unique within the FAL ASE that will provide the services for this class. When qualified by
the identity of its FAL ASE, it unambiguously identifies the class within the scope of the
FAL. The value "NULL" indicates that the class cannot be instantiated. Class IDs between
1 and 255 are reserved by this document to identify standardized classes. They have been
assigned to maintain compatibility with existing national standards. CLASS IDs between
256 and 2048 are allocated for identifying user defined classes.
(4) The "PARENT CLASS:" entry is the name of the parent class for the class being specified.
All attributes defined for the parent class and inherited by it are inherited for the class
being defined, and therefore do not have to be redefined in the template for this class.
NOTE The parent-class "TOP" indicates that the class being defined is an initial class definition. The parent class
TOP is used as a starting point from which all other classes are defined. The use of TOP is reserved for classes
defined by this document.
(5) The "ATTRIBUTES" label indicate that the following entries are attributes defined for the
class.
a) Each of the attribute entries contains a line number in column 1, a mandatory (m) /
optional (o) / conditional (c) / selector (s) indicator in column 2, an attribute type label
in column 3, a name or a conditional expression in column 4, and optionally a list of
enumerated values in column 5. In the column following the list of values, the default
value for the attribute may be specified.
b) Objects are normally identified by a numeric identifier or by an object name, or by
both. In the class templates, these key attributes are defined under the key attribute.
c) The line number defines the sequence and the level of nesting of the line. Each
nesting level is identified by period. Nesting is used to specify
i) fields of a structured attribute (4.1, 4.2, 4.3),
ii) attributes conditional on a constraint statement (Clause 5). Attributes may be
mandatory (5.1) or optional (5.2) if the constraint is true. Not all optional attributes
require constraint statements as does the attribute defined in (5.2).
iii) the selection fields of a choice type attribute (6.1 and 6.2).
(6) The "SERVICES" label indicates that the following entries are services defined for the
class.
a) An (m) in column 2 indicates that the service is mandatory for the class, while an (o)
indicates that it is optional. A (c) in this column indicates that the service is conditional.

– 14 – IEC 61158-5-19:2019 © IEC 2019
When all services defined for a class are defined as optional, at least one has to be
selected when an instance of the class is defined.
b) The label "OpsService" designates an operational service (1).
c) The label "MgtService" designates an management service (2).
d) The line number defines the sequence and the level of nesting of the line. Each
nesting level is identified by period. Nesting within the list of services is used to specify
services conditional on a constraint statement.
3.7.4 Conventions for service definitions
3.7.4.1 General
The service model, service primitives, and time-sequence diagrams used are entirely abstract
descriptions; they do not represent a specification for implementation.
3.7.4.2 Service parameters
Service primitives are used to represent service user/service provider interactions
(ISO/IEC 10731). They convey parameters which indicate information available in the
user/provider interaction. In any particular interface, not all parameters need be explicitly
stated.
The service specifications of this document uses a tabular format to describe the component
parameters of the ASE service primitives. The parameters which apply to each group of
service primitives are set out in tables. Each table consists of up to five columns for the
1) Parameter name,
2) request primitive,
3) indication primitive,
4) response primitive, and
5) confirm primitive.
One parameter (or component 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 specified in the column:
M parameter is mandatory for the primitive
U parameter is a User option, and may or may not be provided depending on dynamic
usage of the service 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 service
user.
— (blank) parameter is never present.
S parameter is a selected item.
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.
3.7.4.3 Service procedures
The procedures are defined in terms of
• the interactions between application entities through the exchange of fieldbus Application
Protocol Data Units, and
• the interactions between an application layer service provider and an application layer
service user in the same system through the invocation of application layer service
primitives.
These procedures are applicable to instances of communication between systems which
support time-constrained communications services within the fieldbus application layer.
4 Concepts
The common concepts and templates used to describe the application layer service in this
document are detailed in IEC 61158-1, Clause 9.
5 Data type ASE
Data types as specified in IEC 61158-1, Clause 9 is applied with the following restrictions:
Only nesting level of 1 is supported.
Only the following basic data types are supported:
BitString8
BitString16
BitString32
BitString64
Unsigned16
Unsigned32
Unsigned64
Integer16
Integer32
Integer64
VisibleString1
Float32
Float64
5.1 Bitstring types
5.1.1 BitString8
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 22
2 Data type Name = Bitstring8
3 Format = FIXED LENGTH
5.1 Octet Length = 1
This type contains 1 element of type BitString.

– 16 – IEC 61158-5-19:2019 © IEC 2019
5.1.2 BitString16
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 23
2 Data type Name = Bitstring16
3 Format = FIXED LENGTH
5.1 Octet Length = 2
This type is a BitString16 and has a length of two octets.
5.1.3 BitString32
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 24
2 Data type Name = Bitstring32
3 Format = FIXED LENGTH
5.1 Octet Length = 4
This type is a BitString16 and has a length of four octets.
5.1.4 BitString64
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 57
2 Data type Name = Bitstring64
3 Format = FIXED LENGTH
5.1 Octet Length = 8
This type is a BitString16 and has a length of eight octets.
5.2 Unsigned types
5.2.1 Unsigned16
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 6
2 Data type Name = Unsigned16
3 Format = FIXED LENGTH
4.1 Octet Length = 2
This type is a binary number. The most significant bit of the most significant octet is always
used as the most significant bit of the binary number; no sign bit is included. This unsigned
type has a length of two octets.
5.2.2 Unsigned32
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 7
2 Data type Name = Unsigned32
3 Format = FIXED LENGTH
4.1 Octet Length = 4
This type is a binary number. The most significant bit of the most significant octet is always
used as the most significant bit of the binary number; no sign bit is included. This unsigned
type has a length of four octets.

5.2.3 Unsigned64
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 56
2 Data type Name = Unsigned64
3 Format = FIXED LENGTH
4.1 Octet Length = 8
This type is a binary number. The most significant bit of the most significant octet is always
used as the most significant bit of the binary number; no sign bit is included. This unsigned
type has a length of eight octets.
5.3 Integer types
5.3.1 Integer16
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 3
2 Data type Name = Integer16
3 Format = FIXED LENGTH
4.1 Octet Length = 2
This integer type is a two’s complement binary number with a length of two octets.
5.3.2 Integer32
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 4
2 Data type Name = Integer32
3 Format = FIXED LENGTH
4.1 Octet Length = 4
This integer type is a two’s complement binary number with a length of four octets.
5.3.3 Integer64
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 55
2 Data type Name = Integer64
3 Format = FIXED LENGTH
4.1 Octet Length = 8
This integer type is a two’s complement binary number with a length of eight octets.
5.4 Floating Point types
5.4.1 Float32
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 8
2 Data type Name = Float32
4 Format = FIXED LENGTH
4.1 Octet Length = 4
This type has a length of four octets. The format for Float32 is that defined by
ISO/IEC/IEEE 60559 as single precision.

– 18 – IEC 61158-5-19:2019 © IEC 2019
5.4.2 Float64
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 15
2 Data type Name = Float64
3 Format = FIXED LENGTH
4.1 Octet Length = 8
This type has a length of eight octets. The format for Float64 is that defined by
ISO/IEC/IEEE 60559 as double precision.
5.5 Structure types
5.5.1 STRING2
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = not used
2 Data type Name = STRING2
3 Format = STRUCTURE
5.1 Number of Fields = 2
5.2.1 Field Name = Charcount_Element
5.2.2  Field Data type = UINT
5.3.1  Field Name = String2contents_Element
5.3.2  Field Data type = OctetString
This IEC 61131-3 data type extension is composed of two elements. Charcount_Element
gives the current number of characters in the String2contents_Element (one UINT per
character). Characters are as specified in ISO/IEC 10646.
6 Communication model specification
6.1 Concepts
6.1.1 Communication mechanisms
Two communication mechanisms are supported by devices within the network:
• cyclic transmission of data in a high efficient manner using a publisher subscriber
model,
• non-cyclic transmission of data using a client server communication model.
AREPs, which act as push publisher or push subscriber, are used for cyclic transmission.
AREPs, which act as a client or server, are used for non-cyclic data transmission.
6.1.2 IDN concept
The application data which is transmitted cyclically and non-cyclically between FAL users is
mapped on so-called identification numbers (IDNs). These IDNs correspond to the APOs as
defined and are described in Annex A of IEC 61158-4-19.
6.2 ASEs
6.2.1 Identification number (IDN) ASE
6.2.1.1 Overview
The IDN ASE provides read and write access to the attributes of IDNs provided by a device.

6.2.1.2 IDN class specification
6.2.1.2.1 Formal model
FAL ASE: IDN ASE
CLASS: IDN
CLASS ID: not used
PARENT CLASS: TOP
ATTRIBUTES:
1 (m) Key Attribute: Identification
1.1 (m) Key Attribute: Identification number
1.2 (o) Key Attribute: Structure element
1.3 (o) Key Attribute: Structure index
2 (o) Attribute: Name
3 (m) Attribute: Data Attribute
4 (o) Attribute: Unit
5 (o) Attribute: Minimum value
6 (o) Attribute: Maximum value
7 (m) Attribute: Operation Data
SERVICES:
1 (m) OpsService: Read
2 (m) OpsService: Write
6.2.1.2.2 Attributes
Identification
This key attribute identifies an instance of this object class. The addressing can be simple or
extended.
Identification num
...


IEC 61158-5-19 ®
Edition 4.0 2019-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial communication networks – Fieldbus specifications –
Part 5-19: Application layer service definition – Type 19 elements

Réseaux de communication industriels – Spécifications des bus de terrain –
Partie 5-19: Définition des services de la couche application – Éléments
de type 19
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IEC 61158-5-19 ®
Edition 4.0 2019-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial communication networks – Fieldbus specifications –

Part 5-19: Application layer service definition – Type 19 elements

Réseaux de communication industriels – Spécifications des bus de terrain –

Partie 5-19: Définition des services de la couche application – Éléments

de type 19
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040.40; 35.100.70; 35.110 ISBN 978-2-8322-9145-0

– 2 – IEC 61158-5-19:2019 © IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
1.1 General . 7
1.2 Specifications . 8
1.3 Conformance . 8
2 Normative references . 8
3 Terms, definitions, symbols, abbreviations and conventions . 9
3.1 ISO/IEC 7498-1 terms . 9
3.2 ISO/IEC 8822 terms . 9
3.3 ISO/IEC 9545 terms . 9
3.4 ISO/IEC 8824-1 terms . 10
3.5 Fieldbus application-layer specific definitions . 10
3.6 Abbreviations and symbols . 12
3.7 Conventions . 12
3.7.1 Overview . 12
3.7.2 General conventions . 12
3.7.3 Conventions for class definitions . 12
3.7.4 Conventions for service definitions . 14
4 Concepts . 15
5 Data type ASE . 15
5.1 Bitstring types . 15
5.1.1 BitString8 . 15
5.1.2 BitString16. 16
5.1.3 BitString32. 16
5.1.4 BitString64. 16
5.2 Unsigned types . 16
5.2.1 Unsigned16 . 16
5.2.2 Unsigned32 . 16
5.2.3 Unsigned64 . 17
5.3 Integer types . 17
5.3.1 Integer16 . 17
5.3.2 Integer32 . 17
5.3.3 Integer64 . 17
5.4 Floating Point types . 17
5.4.1 Float32 . 17
5.4.2 Float64 . 18
5.5 Structure types . 18
5.5.1 STRING2 . 18
6 Communication model specification . 18
6.1 Concepts . 18
6.1.1 Communication mechanisms . 18
6.1.2 IDN concept . 18
6.2 ASEs . 18
6.2.1 Identification number (IDN) ASE . 18
6.2.2 CYCIDN ASE . 21

6.2.3 Management (MGT) ASE . 24
6.3 ARs . 31
6.3.1 General . 31
6.3.2 Point-to-point user-triggered confirmed client/server AREP (SVC) . 31
6.3.3 Point-to-point network-scheduled unconfirmed publisher/subscriber

AREP (RTC-MS) . 31
6.3.4 Point-to-multipoint network-scheduled unconfirmed publisher/subscriber
AREP (RTC-CC) . 32
6.4 Summary of AR classes . 32
6.5 Permitted FAL services by AREP role . 33
Bibliography . 34

Table 1 – Read service parameters. 20
Table 2 – Write service parameters . 21
Table 3 – Read service parameters. 22
Table 4 – Write service parameters . 23
Table 5 – Notify service parameters . 24
Table 6 – Get network status service parameters . 25
Table 7 – Get device status service parameters . 26
Table 8 – Network status change report service parameters . 26
Table 9 – Station status change report service parameters . 27
Table 10 – Set device status service parameters . 27
Table 11 – Enable RTC service parameters . 28
Table 12 – Enable hotplug service parameters . 29
Table 13 – Notify RTC service parameters . 30
Table 14 – Disable RTC service parameters . 30
Table 15 – AREP (SVC) class summary . 32
Table 16 – AREP (RTC-MS) class summary . 32
Table 17 – AREP (RTC-CC) class summary . 33
Table 18 – FAL services by AR type . 33

– 4 – IEC 61158-5-19:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 5-19: Application layer service definition –
Type 19 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
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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
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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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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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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
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
Attention is drawn to the fact that the use of the associated protocol type is restricted by its
intellectual-property-right holders. In all cases, the commitment to limited release of
intellectual-property-rights made by the holders of those rights permits a layer protocol type to
be used with other layer protocols of the same type, or in other type combinations explicitly
authorized by its intellectual-property-right holders.
NOTE Combinations of protocol types are specified in IEC 61784-1 and IEC 61784-2.
International Standard IEC 61158-5-19 has been prepared by subcommittee 65C: Industrial
networks, of IEC technical committee 65: Industrial-process measurement, control and
automation.
This fourth edition cancels and replaces the third edition published in 2014. This edition
constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous
edition:
• improving the hotplug and redundancy features;
• improving the phase switching and the error handling;
• editorial improvements.
The text of this International Standard is based on the following documents:
FDIS Report on voting
65C/947/FDIS 65C/950/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 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 61158-5-19:2019 © IEC 2019
INTRODUCTION
This document 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.
The application service is provided by the application protocol making use of the services
available from the data-link or other immediately lower layer. This document defines the
application service characteristics that fieldbus applications and/or system management may
exploit.
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 application layer service defined in this document is a conceptual architectural
service, independent of administrative and implementation divisions.

INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 5-19: Application layer service definition –
Type 19 elements
1 Scope
1.1 General
The fieldbus application layer (FAL) provides user programs with a means to access the
fieldbus communication environment. In this respect, the FAL can be viewed as a “window
between corresponding application programs.”
This part of IEC 61158 provides common elements for basic time-critical and non-time-critical
messaging communications between application programs in an automation environment and
material specific to Type 19 fieldbus. 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 International Standard defines in an abstract way the externally visible service provided
by the fieldbus application layer in terms of
a) an abstract model for defining application resources (objects) capable of being
manipulated by users via the use of the FAL service,
b) the primitive actions and events of the service;
c) the parameters associated with each primitive action and event, and the form which they
take; and
d) the interrelationship between these actions and events, and their valid sequences.
The purpose of this document is to define the services provided to
a) the FAL user at the boundary between the user and the application layer of the fieldbus
reference model, and
b) Systems Management at the boundary between the application layer and Systems
Management of the fieldbus reference model.
This document specifies the structure and services of the fieldbus application layer, in
conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application
layer structure (ISO/IEC 9545).
FAL services and protocols are provided by FAL application-entities (AE) contained within the
application processes. The FAL AE is composed of a set of object-oriented application service
elements (ASEs) and a layer management entity (LME) that manages the AE. The ASEs
provide communication services that operate on a set of related application process object
(APO) classes. One of the FAL ASEs is a management ASE that provides a common set of
services for the management of the instances of FAL classes.
Although these services specify, from the perspective of applications, how request and
responses are issued and delivered, they do not include a specification of what the requesting
and responding applications are to do with them. That is, the behavioral aspects of the
applications are not specified; only a definition of what requests and responses they can

– 8 – IEC 61158-5-19:2019 © IEC 2019
send/receive is specified. This permits greater flexibility to the FAL users in standardizing
such object behavior. In addition to these services, some supporting services are also defined
in this document to provide access to the FAL to control certain aspects of its operation.
1.2 Specifications
The principal objective of this document is to specify the characteristics of conceptual
application layer services suitable for time-critical communications, and thus supplement the
OSI Basic Reference Model in guiding the development of application layer protocols for time-
critical communications.
A secondary objective is to provide migration paths from previously-existing industrial
communications protocols. It is this latter objective which gives rise to the diversity of services
standardized as the various Types of IEC 61158, and the corresponding protocols
standardized in subparts of IEC 61158-6.
This specification may be used as the basis for formal application 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 document does not specify individual implementations or products, nor does it constrain
the implementations of application layer entities within industrial automation systems.
There is no conformance of equipment to this application layer service definition standard.
Instead, conformance is achieved through implementation of conforming application layer
protocols that fulfill the application layer services as defined in this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
NOTE All parts of the IEC 61158 series, as well as 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.
IEC 61131-3, Programmable controllers – Part 3: Programming languages
IEC 61158-1:2019, Industrial communication networks – Fieldbus specifications – Part 1:
Overview and guidance for the IEC 61158 and IEC 61784 series
IEC 61158-4-19:2019, Industrial communication networks – Fieldbus specifications –
Part 4-19: Data-link layer protocol specification – Type 19 elements
ISO/IEC 7498-1, Information technology – Open Systems Interconnection – Basic Reference
Model: The Basic Model
ISO/IEC 8822, Information technology – Open Systems Interconnection – Presentation
service definition
ISO/IEC 8824-1, Information technology – Abstract Syntax Notation One (ASN.1):
Specification of basic notation
ISO/IEC 9545, Information technology – Open Systems Interconnection – Application Layer
structure
ISO/IEC 10646, Information technology – Universal Coded Character Set (UCS)
ISO/IEC 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
ISO/IEC/IEEE 60559, Information technology – Microprocessor Systems – Floating-Point
arithmetic
3 Terms, definitions, symbols, abbreviations and conventions
For the purposes of this document, the following terms, definitions, symbols, abbreviations
and conventions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 ISO/IEC 7498-1 terms
For the purposes of this document, the following terms as defined in ISO/IEC 7498-1 apply:
a) application entity
b) application process
c) application protocol data unit
d) application service element
e) application entity invocation
f) application process invocation
g) application transaction
h) real open system
i) transfer syntax
3.2 ISO/IEC 8822 terms
For the purposes of this document, the following terms as defined in ISO/IEC 8822 apply:
a) abstract syntax
b) presentation context
3.3 ISO/IEC 9545 terms
For the purposes of this document, the following terms as defined in ISO/IEC 9545 apply:
a) application-association
b) application-context
c) application context name
d) application-entity-invocation

– 10 – IEC 61158-5-19:2019 © IEC 2019
e) application-entity-type
f) application-process-invocation
g) application-process-type
h) application-service-element
i) application control service element
3.4 ISO/IEC 8824-1 terms
For the purposes of this document, the following terms as defined in ISO/IEC 8824-1 apply:
a) object identifier
b) type
3.5 Fieldbus application-layer specific definitions
3.5.1
coded character set
code
set of unambiguous rules that establish a character set and one-to-one relationship between
the characters of the set and their representation by one or more bit combinations
3.5.2
cross communication
direct data transfer between slave devices (without active involvement of master)
3.5.3
cycle time
duration of a communication cycle
3.5.4
cyclic data
part of a telegram, which does not change its meaning during cyclic operation of the network
3.5.5
device
slave in the communication network
Note 1 to entry: Examples are a power drive system as defined in the IEC 61800-7 (all parts), I/O stations as
defined in IEC 61131 (all parts), etc.
3.5.6
device status
four adjacent octets inside the acknowledge telegram containing status information for each
device
3.5.7
element
part of IDNs
Note 1 to entry: Each IDN has 7 elements, whereas each one has a specific meaning (e.g., number, name, data).
3.5.8
hot plug
possibility to open the communication network and insert or remove slaves while the network
is still in real-time operation

3.5.9
identification number
designation of operating data under which a data block is preserved with its attribute, name,
unit, minimum and maximum input values, and the data
3.5.10
loopback
mode by which a device passes on a received telegram to the same port and to the other port,
either changed or unchanged
3.5.11
master
node which assigns the other nodes (i.e., slaves) the right to transmit
3.5.12
physical layer
first layer of the ISO-OSI reference model
3.5.13
protocol
convention about the data formats, time sequences, and error correction in the data exchange
of communication systems
3.5.14
service channel
SVC
non real-time transmission of information upon master request during RT channel
3.5.15
slave
node which is assigned the right to transmit by the master
3.5.16
station
node
3.5.17
topology
physical network architecture with respect to the connection between the stations of the
communication system
– 12 – IEC 61158-5-19:2019 © IEC 2019
3.6 Abbreviations and symbols
AHS Service transport handshake of the device (acknowledge HS)
AP Application Process
APO Application Object
AR Application Relationship
AREP Application Relationship End Point
ASE Application Service Element
CC-data Cross Communication
Cnf Confirmation
DA Destination address
DAT Duration of acknowledge telegram
FAL Fieldbus Application Layer
ID Identification Number
IDN Identification Number
Ind Indication
MS Master Slave
NRC Non Real Time Channel
NA Not applicable
Req Request
Rsp Response
RTC Real Time Channel
RTE Real Time Ethernet
3.7 Conventions
3.7.1 Overview
The FAL is defined as a set of object-oriented ASEs. Each ASE is specified in a separate
subclause. Each ASE specification is composed of two parts, its class specification, and its
service specification.
The class specification defines the attributes of the class. The attributes are accessible from
instances of the class using the Object Management ASE services specified in Clause 5 of
this document. The service specification defines the services that are provided by the ASE.
3.7.2 General conventions
This document uses the descriptive conventions given in ISO/IEC 10731.
3.7.3 Conventions for class definitions
Class definitions are described using templates. Each template consists of a list of attributes
for the class. The general form of the template is shown below:
FAL ASE: ASE Name
CLASS:  Class name
CLASS ID: #
PARENT CLASS: Parent class name
ATTRIBUTES:
1 (o) Key Attribute: numeric identifier
2 (o) Key Attribute: name
3 (m) Attribute: attribute name(values)
4 (m) Attribute: attribute name(values)

4.1 (s) Attribute: attribute name(values)
4.2 (s) Attribute: attribute name(values)
4.3 (s) Attribute: attribute name(values)
5. (c) Constraint: constraint expression
5.1 (m) Attribute: attribute name(values)
5.2 (o) Attribute: attribute name(values)
6 (m) Attribute: attribute name(values)
6.1 (s) Attribute: attribute name(values)
6.2 (s) Attribute: attribute name(values)
SERVICES:
1 (o) OpsService: service name
2. (c) Constraint: constraint expression
2.1 (o)   OpsService:   service name
3 (m) MgtService: service name

(1) The "FAL ASE:" entry is the name of the FAL ASE that provides the services for the class
being specified.
(2) The "CLASS:" entry is the name of the class being specified. All objects defined using this
template will be an instance of this class. The class may be specified by this document, or
by a user of this document.
(3) The "CLASS ID:" entry is a number that identifies the class being specified. This number is
unique within the FAL ASE that will provide the services for this class. When qualified by
the identity of its FAL ASE, it unambiguously identifies the class within the scope of the
FAL. The value "NULL" indicates that the class cannot be instantiated. Class IDs between
1 and 255 are reserved by this document to identify standardized classes. They have been
assigned to maintain compatibility with existing national standards. CLASS IDs between
256 and 2048 are allocated for identifying user defined classes.
(4) The "PARENT CLASS:" entry is the name of the parent class for the class being specified.
All attributes defined for the parent class and inherited by it are inherited for the class
being defined, and therefore do not have to be redefined in the template for this class.
NOTE The parent-class "TOP" indicates that the class being defined is an initial class definition. The parent class
TOP is used as a starting point from which all other classes are defined. The use of TOP is reserved for classes
defined by this document.
(5) The "ATTRIBUTES" label indicate that the following entries are attributes defined for the
class.
a) Each of the attribute entries contains a line number in column 1, a mandatory (m) /
optional (o) / conditional (c) / selector (s) indicator in column 2, an attribute type label
in column 3, a name or a conditional expression in column 4, and optionally a list of
enumerated values in column 5. In the column following the list of values, the default
value for the attribute may be specified.
b) Objects are normally identified by a numeric identifier or by an object name, or by
both. In the class templates, these key attributes are defined under the key attribute.
c) The line number defines the sequence and the level of nesting of the line. Each
nesting level is identified by period. Nesting is used to specify
i) fields of a structured attribute (4.1, 4.2, 4.3),
ii) attributes conditional on a constraint statement (Clause 5). Attributes may be
mandatory (5.1) or optional (5.2) if the constraint is true. Not all optional attributes
require constraint statements as does the attribute defined in (5.2).
iii) the selection fields of a choice type attribute (6.1 and 6.2).
(6) The "SERVICES" label indicates that the following entries are services defined for the
class.
a) An (m) in column 2 indicates that the service is mandatory for the class, while an (o)
indicates that it is optional. A (c) in this column indicates that the service is conditional.

– 14 – IEC 61158-5-19:2019 © IEC 2019
When all services defined for a class are defined as optional, at least one has to be
selected when an instance of the class is defined.
b) The label "OpsService" designates an operational service (1).
c) The label "MgtService" designates an management service (2).
d) The line number defines the sequence and the level of nesting of the line. Each
nesting level is identified by period. Nesting within the list of services is used to specify
services conditional on a constraint statement.
3.7.4 Conventions for service definitions
3.7.4.1 General
The service model, service primitives, and time-sequence diagrams used are entirely abstract
descriptions; they do not represent a specification for implementation.
3.7.4.2 Service parameters
Service primitives are used to represent service user/service provider interactions
(ISO/IEC 10731). They convey parameters which indicate information available in the
user/provider interaction. In any particular interface, not all parameters need be explicitly
stated.
The service specifications of this document uses a tabular format to describe the component
parameters of the ASE service primitives. The parameters which apply to each group of
service primitives are set out in tables. Each table consists of up to five columns for the
1) Parameter name,
2) request primitive,
3) indication primitive,
4) response primitive, and
5) confirm primitive.
One parameter (or component 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 specified in the column:
M parameter is mandatory for the primitive
U parameter is a User option, and may or may not be provided depending on dynamic
usage of the service 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 service
user.
— (blank) parameter is never present.
S parameter is a selected item.
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.
3.7.4.3 Service procedures
The procedures are defined in terms of
• the interactions between application entities through the exchange of fieldbus Application
Protocol Data Units, and
• the interactions between an application layer service provider and an application layer
service user in the same system through the invocation of application layer service
primitives.
These procedures are applicable to instances of communication between systems which
support time-constrained communications services within the fieldbus application layer.
4 Concepts
The common concepts and templates used to describe the application layer service in this
document are detailed in IEC 61158-1, Clause 9.
5 Data type ASE
Data types as specified in IEC 61158-1, Clause 9 is applied with the following restrictions:
Only nesting level of 1 is supported.
Only the following basic data types are supported:
BitString8
BitString16
BitString32
BitString64
Unsigned16
Unsigned32
Unsigned64
Integer16
Integer32
Integer64
VisibleString1
Float32
Float64
5.1 Bitstring types
5.1.1 BitString8
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 22
2 Data type Name = Bitstring8
3 Format = FIXED LENGTH
5.1 Octet Length = 1
This type contains 1 element of type BitString.

– 16 – IEC 61158-5-19:2019 © IEC 2019
5.1.2 BitString16
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 23
2 Data type Name = Bitstring16
3 Format = FIXED LENGTH
5.1 Octet Length = 2
This type is a BitString16 and has a length of two octets.
5.1.3 BitString32
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 24
2 Data type Name = Bitstring32
3 Format = FIXED LENGTH
5.1 Octet Length = 4
This type is a BitString16 and has a length of four octets.
5.1.4 BitString64
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 57
2 Data type Name = Bitstring64
3 Format = FIXED LENGTH
5.1 Octet Length = 8
This type is a BitString16 and has a length of eight octets.
5.2 Unsigned types
5.2.1 Unsigned16
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 6
2 Data type Name = Unsigned16
3 Format = FIXED LENGTH
4.1 Octet Length = 2
This type is a binary number. The most significant bit of the most significant octet is always
used as the most significant bit of the binary number; no sign bit is included. This unsigned
type has a length of two octets.
5.2.2 Unsigned32
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 7
2 Data type Name = Unsigned32
3 Format = FIXED LENGTH
4.1 Octet Length = 4
This type is a binary number. The most significant bit of the most significant octet is always
used as the most significant bit of the binary number; no sign bit is included. This unsigned
type has a length of four octets.

5.2.3 Unsigned64
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 56
2 Data type Name = Unsigned64
3 Format = FIXED LENGTH
4.1 Octet Length = 8
This type is a binary number. The most significant bit of the most significant octet is always
used as the most significant bit of the binary number; no sign bit is included. This unsigned
type has a length of eight octets.
5.3 Integer types
5.3.1 Integer16
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 3
2 Data type Name = Integer16
3 Format = FIXED LENGTH
4.1 Octet Length = 2
This integer type is a two’s complement binary number with a length of two octets.
5.3.2 Integer32
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 4
2 Data type Name = Integer32
3 Format = FIXED LENGTH
4.1 Octet Length = 4
This integer type is a two’s complement binary number with a length of four octets.
5.3.3 Integer64
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 55
2 Data type Name = Integer64
3 Format = FIXED LENGTH
4.1 Octet Length = 8
This integer type is a two’s complement binary number with a length of eight octets.
5.4 Floating Point types
5.4.1 Float32
CLASS:  Data type
ATTRIBUTES:
1 Data type Numeric Identifier = 8
2 Data type Name = Float32
4 Forma
...

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Frequently Asked Questions

IEC 61158-5-19:2019 is a standard published by the International Electrotechnical Commission (IEC). Its full title is "Industrial communication networks - Fieldbus specifications - Part 5-19: Application layer service definition - Type 19 elements". This standard covers: IEC 61158-5-19:2019 defines the services provided to the FAL user at the boundary between the user and the application layer of the fieldbus reference model, and Systems Management at the boundary between the application layer and Systems Management of the fieldbus reference model. This standard specifies the structure and services of the IEC fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545). This fourth edition cancels and replaces the third edition published in 2014 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: • improving the hotplug and redundancy features; • improving the phase switching and the error handling; • editorial improvements.

IEC 61158-5-19:2019 defines the services provided to the FAL user at the boundary between the user and the application layer of the fieldbus reference model, and Systems Management at the boundary between the application layer and Systems Management of the fieldbus reference model. This standard specifies the structure and services of the IEC fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545). This fourth edition cancels and replaces the third edition published in 2014 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: • improving the hotplug and redundancy features; • improving the phase switching and the error handling; • editorial improvements.

IEC 61158-5-19:2019 is classified under the following ICS (International Classification for Standards) categories: 25.040.40 - Industrial process measurement and control; 35.100.70 - Application layer; 35.110 - Networking. The ICS classification helps identify the subject area and facilitates finding related standards.

IEC 61158-5-19:2019 has the following relationships with other standards: It is inter standard links to IEC 61158-5-19:2014. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.

You can purchase IEC 61158-5-19:2019 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of IEC standards.