IEC 61158-5-2:2010

Industrial communication networks - Fieldbus specifications - Part 5-2: Application layer service definition - Type 2 elements

IEC 61158-5-2:2010(E) defines in an abstract way the externally visible service provided by the Type 2 fieldbus application layer in terms of an abstract model for defining application resources (objects) capable of being manipulated by users via the use of the FAL service, the primitive actions and events of the service; the parameters associated with each primitive action and event, and the form which they take; and the interrelationship between these actions and events, and their valid sequences. This second edition cancels and replaces the first edition published in 2007 and constitutes a technical revision. The main changes with respect to the previous edition are:
- Clause 2 and Bibliography: update of normative and bibliographic references;
- subclause 6.1.3: update lists with new objects;
- subclause 6.2.1.2.6: update of the Time Sync ASE/object (to match new IEC 61558);
- new subclause 6.2.1.2.7: new Parameter ASE/object;
- subclause 6.2.1.3: update/add services for Time Sync and Parameter ASEs;
- subclause 6.2.2.3: minor updates to the Connection Manager ASE services;
- subclause 6.4: add Parameter ASE to the object table;
- subclause 6.5: update contents of service table for Time Sync and Parameter ASEs.

General Information

• Status: Published
• Publication Date: 04-Aug-2010
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 29.120.30 - Plugs, socket-outlets, couplers
• ICS: 35.100.70 - Application layer
• ICS: 35.110 - Networking
• Technical Committee: SC 65C - Industrial networks
• Drafting Committee: WG 9 - TC 65/SC 65C/WG 9
• Current Stage: DELPUB - Deleted Publication
• Start Date: 18-Aug-2014
• Completion Date: 26-Oct-2025

Relations

• Revised: IEC 61158-5-2:2014 - Industrial communication networks - Fieldbus specifications - Part 5-2: Application layer service definition - Type 2 elements
• Effective Date: 05-Sep-2023
• Revises: IEC 61158-5-2:2007 - Industrial communication networks - Fieldbus specifications - Part 5-2: Application layer service definition - Type 2 elements
• Effective Date: 05-Sep-2023

Overview

IEC 61158-5-2:2010 - "Industrial communication networks - Fieldbus specifications - Part 5-2: Application layer service definition - Type 2 elements" - is the IEC international standard that defines, in an abstract and implementation‑independent way, the externally visible services of a Type 2 fieldbus application layer. It specifies an abstract model for application resources (objects), the Fieldbus Application Layer (FAL) service primitives (actions and events), the parameters for each primitive, valid sequences and interrelationships. Edition 2.0 (2010) replaces the 2007 edition and includes technical revisions and additions.

Key topics and technical requirements

• Abstract application model: Formal definition of application resources (objects), classes, instances and attributes that users and tools manipulate via the FAL service.
• FAL service primitives: Specification of primitive actions, events, their parameters and valid message sequences for Type 2 elements.
• Application Service Elements (ASEs): Detailed ASE definitions (e.g., Identity, Data Type, Connection Manager, Time Sync ASE, Parameter ASE) and their services.
• Time synchronization and parameter management: Updates to Time Sync ASE/object to match newer IEC references and a newly introduced Parameter ASE/object included in this edition.
• Connection and transport model: Communication model covering connections (I/O, explicit messaging), transport classes, triggering, production timing and connection-management services.
• State machines and service tables: State transition diagrams, service parameter tables (Get/Set Attribute, Create/Delete, CM_Open/CM_Close, etc.) and permitted FAL services per AR type.
• Conformance and references: Normative references and alignment with ISO/IEC OSI terminology and other IEC references (updated normative and bibliographic references).

Practical applications and users

• Who uses it: Protocol designers, fieldbus stack implementers, device manufacturers, systems integrators, automation engineers and test laboratories working with Type 2 fieldbus profiles.
• Where it applies: Industrial automation systems requiring standardized application‑layer behaviour - e.g., I/O devices, controllers, gateways and network management tools - where predictable object models, time synchronization and connection management are required.
• Benefits: Ensures interoperability across devices and vendors by defining consistent application services, object models and service semantics for Type 2 fieldbus implementations.

Related standards

• IEC 61158 family (other parts defining physical, data-link and other application layer types)
• ISO/IEC OSI references and related IEC normative documents cited in the standard (see Clause 2 and Bibliography)
• Time sync cross‑references (this edition aligns Time Sync ASE updates with the relevant IEC time synchronization reference noted in the document)

Keywords: IEC 61158-5-2, fieldbus, Type 2, application layer, FAL service, ASE, Time Sync, Parameter ASE, Connection Manager, industrial communication standards.

Standards Content (Sample)

IEC 61158-5-2 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
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Industrial communication networks – Fieldbus specifications –
Part 5-2: Application layer service definition – Type 2 elements

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IEC 61158-5-2 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
colour
inside
Industrial communication networks – Fieldbus specifications –
Part 5-2: Application layer service definition – Type 2 elements

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XH
ICS 25.04.40; 35.100.70; 35.110 ISBN 978-2-88912-105-2
– 2 – 61158-5-2 © IEC:2010(E)
CONTENTS
FOREWORD.5
INTRODUCTION.7
1 Scope.8
1.1 Overview .8
1.2 Specifications.9
1.3 Conformance.9
2 Normative references .9
3 Terms, definitions, symbols, abbreviations and conventions .10
3.1 ISO/IEC 7498-1 terms .10
3.2 ISO/IEC 8822 terms .11
3.3 ISO/IEC 9545 terms .11
3.4 ISO/IEC 8824 terms .11
3.5 Type 2 fieldbus data-link layer terms .11
3.6 Type 2 fieldbus application-layer specific definitions.11
3.7 Type 2 abbreviations and symbols.18
3.8 Conventions .19
4 Common concepts.22
5 Data type ASE.22
5.1 General .22
5.2 Formal definition of data type objects .22
5.3 FAL defined data types.22
5.4 Data type ASE service specification .32
6 Communication model specification.32
6.1 Concepts.32
6.2 ASEs.40
6.3 ARs .155
6.4 Summary of FAL classes .192
6.5 Permitted FAL services by AR type .193
Bibliography.195

Figure 1 – Overview of ASEs and object classes .34
Figure 2 – Addressing format using MAC, class, instance and attribute IDs .35
Figure 3 – Identity object state transition diagram .52
Figure 4 – Static Assembly state transition diagram .57
Figure 5 – Dynamic Assembly state transition diagram .58
Figure 6 – Typical timing relationships for acknowledged data production.67
Figure 7 – Example of a COS system with two acking devices .67
Figure 8 – Message flow in COS connection – one Connection object, one consumer.67
Figure 9 – Message flow in COS connection – multiple consumers .68
Figure 10 – CPF2 time synchronization offset clock model.80
Figure 11 – CPF2 time synchronization system with offset clock model .80
Figure 12 – CPF2 time synchronization group startup sequence .83
Figure 13 – Parameter object state transition diagram .89

61158-5-2 © IEC:2010(E) – 3 –
Figure 14 – Example of Find_Next_Object_Instance service . 114
Figure 15 – Transmission trigger timer.149
Figure 16 – Inactivity watchdog timer.150
Figure 17 – Using tools for configuration.151
Figure 18 – Production inhibit timer .152
Figure 19 – Context of transport services within the connection model. 158
Figure 20 – Application–to–application view of data transfer . 158
Figure 21 – Data flow diagram for a link producer .159
Figure 22 – Data flow diagram for a link consumer.160
Figure 23 – Triggers .161
Figure 24 – Binding transport instances to the producer and consumer of a transport
connection that does not have a reverse data path .162
Figure 25 – Binding transport instances to the producers and consumers of a transport
connection that does have a reverse data path . 162
Figure 26 – Binding transport instances to the producer and consumers of a multipoint
connection when the transport connection does not have a reverse data path . 163
Figure 27 – Binding transport instances to the producers and consumers of a
multipoint connection when the transport connection does have reverse data paths .163

Table 1 – Valid IANA MIB printer codes for character set selection .31
Table 2 – Common elements .37
Table 3 – ST language elements.38
Table 4 – Type conversion operations.38
Table 5 – Values of implementation-dependent parameters .39
Table 6 – Extensions to IEC 61131-3:2003 .40
Table 7 – Identity object state event matrix .53
Table 8 – Static Assembly state event matrix .57
Table 9 – Dynamic Assembly state event matrix .58
Table 10 – Message Router object Forward_Open parameters .61
Table 11 – Acknowledge Handler object state event matrix.64
Table 12 – Producing I/O application object state event matrix .65
Table 13 – Profile identification.77
Table 14 – Profile default settings and ranges .77
Table 15 – Default PTP clock settings.78
Table 16 – Hand_Set clock quality management .79
Table 17 – Parameter object state event matrix .89
Table 18 – Status codes .92
Table 19 – Get_Attribute_All service parameters .94
Table 20 – Set_Attribute_All service parameters.95
Table 21 – Get_Attribute_List service parameters.97
Table 22 – Set_Attribute_List service parameters .99
Table 23 – Reset service parameters.101
Table 24 – Start service parameters .103
Table 25 – Stop service parameters.105

– 4 – 61158-5-2 © IEC:2010(E)
Table 26 – Create service parameters .106
Table 27 – Delete service parameters.108
Table 28 – Get_Attribute_Single service parameters. 109
Table 29 – Set_Attribute_Single service parameters . 111
Table 30 – Find_Next_Object_Instance service parameters . 112
Table 31 – NOP service parameters .115
Table 32 – Apply_Attributes service parameters . 116
Table 33 – Save service parameters .118
Table 34 – Restore service parameters.119
Table 35 – Group_Sync service parameters.121
Table 36 – Add_AckData_Path service parameters.123
Table 37 – Remove_AckData_Path service parameters . 124
Table 38 – Get-Enum_String service parameters .125
Table 39 – CM_Open service parameters .133
Table 40 – CM_Close service parameters.135
Table 41 – CM_ Unconnected_Send service parameters . 137
Table 42 – CM_Get_Connection_Data service parameters . 139
Table 43 – CM_Search_Connection_Data service parameters . 140
Table 44 – CM_Get_Connection_Data service parameters . 141
Table 45 – I/O Connection object attribute access .146
Table 46 – Bridged Connection object attribute access .147
Table 47 – Explicit messaging object attribute access. 148
Table 48 – Connection_Bind service parameters . 153
Table 49 – Service_Name service parameters .154
Table 50 – How production trigger, transport class, and CM_RPI determine when data
is produced.157
Table 51 – Transport classes .168
Table 52 – UCMM_Create service parameters .185
Table 53 – UCMM_Delete service parameters .186
Table 54 – UCMM_Write service parameters .187
Table 55 – UCMM_Abort service parameters .188
Table 56 – TR_Write service parameters .189
Table 57 – TR_Trigger service parameters .190
Table 58 – TR_Packet_arrived service parameters .190
Table 59 – TR_Ack_received service parameters. 191
Table 60 – TR_Verify service parameters .191
Table 61 – TR_Status_updated service parameters .192
Table 62 – FAL class summary .193
Table 63 – FAL services by AR type .194

61158-5-2 © IEC:2010(E) – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 5-2: Application layer service definition –
Type 2 elements
FOREWORD
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
NOTE 1 Use of some of the associated protocol types is restricted by their intellectual-property-right holders. In
all cases, the commitment to limited release of intellectual-property-rights made by the holders of those rights
permits a particular data-link layer protocol type to be used with physical layer and application layer protocols in
Type combinations as specified explicitly in the IEC 61784 series. Use of the various protocol types in other
combinations may require permission from their respective intellectual-property-right holders.
International Standard IEC 61158-5-2 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 2007. This edition
constitutes a technical revision.
The main changes with respect to the previous edition are listed below:
• Clause 2 and Bibliography: update of normative and bibliographic references

– 6 – 61158-5-2 © IEC:2010(E)
• subclause 6.1.3: update lists with new objects
• subclause 6.2.1.2.6: update of the Time Sync ASE/object (to match new IEC 61558)
• new subclause 6.2.1.2.7: new Parameter ASE/object
• subclause 6.2.1.3: update/add services for Time Sync and Parameter ASEs
• subclause 6.2.2.3: minor updates to the Connection Manager ASE services
• subclause 6.4: add Parameter ASE to the object table
• subclause 6.5: update contents of service table for Time Sync and Parameter ASEs
The text of this standard is based on the following documents:
FDIS Report on voting
65C/606/FDIS 65C/620/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with ISO/IEC Directives, Part 2.
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.
NOTE 2 The revision of this standard will be synchronized with the other parts of the IEC 61158 series.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
61158-5-2 © IEC:2010(E) – 7 –
INTRODUCTION
This part of IEC 61158 is one of a series produced to facilitate the interconnection of
automation system components. It is related to other standards in the set as defined by the
“three-layer” fieldbus reference model described in IEC/TR 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 standard 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 standard is a conceptual architectural
service, independent of administrative and implementation divisions.

– 8 – 61158-5-2 © IEC:2010(E)
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 5-2: Application layer service definition –
Type 2 elements
1 Scope
1.1 Overview
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 standard 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 2 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 standard defines in an abstract way the externally visible service provided by the Type 2
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 standard 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 standard specifies the structure and services of the Type 2 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

61158-5-2 © IEC:2010(E) – 9 –
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 standard to provide access to the FAL to control certain aspects of its operation.
1.2 Specifications
The principal objective of this standard 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 standard 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 Type 2 application layer services as defined in this standard.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60559, Binary floating-point arithmetic for microprocessor systems
IEC 61131-3:2003, Programmable controllers – Part 3: Programming languages
IEC/TR 61158-1:2010 , Industrial communication networks – Fieldbus specifications – Part 1:
Overview and guidance for the IEC 61158 and IEC 61784 series
IEC 61158-3-2:2007, Industrial communication networks – Fieldbus specifications - Part 3-2:
Data-link layer service definition – Type 2 elements
IEC 61158-4-2:2010 , Industrial communication networks – Fieldbus specifications – Part 4-2:
Data-link layer protocol specification – Type 2 elements
IEC 61158-6-2:2010 , Industrial communication networks – Fieldbus specifications – Part 6-2:
Application layer protocol specification – Type 2 elements
___________
To be published.
– 10 – 61158-5-2 © IEC:2010(E)
IEC 61588:2009, Precision clock synchronization protocol for networked measurement and
control systems
IEC 61784-3-2, Industrial communications networks – Profiles – Part 3-2: Functional safety
fieldbuses – Additional specifications for CPF 2
ISO/IEC 646, Information technology – ISO 7–bit coded character set for information
interchange
ISO/IEC 7498-1, Information technology – Open Systems Interconnection – Basic Reference
Model: The Basic Model
ISO/IEC 8859 (all parts), Information technology – 8-bit single-byte coded graphic character
sets
ISO/IEC 8859-1, Information technology – 8-bit single-byte coded graphic character sets –
Part 1: Latin alphabet No. 1
ISO/IEC 9545, Information technology – Open Systems Interconnection – Application Layer
structure
ISO/IEC 10646, Information technology – Universal Multiple-Octet Coded Character Set
(UCS)
ISO/IEC 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
ISO 639-2, Codes for the representation of names of languages – Part 2: Alpha-3 code
ISO 11898:1993 , Road vehicles – Interchange of digital information – Controller area
network (CAN) for high-speed communication
IETF RFC 1759, Printer MIB, 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 ISO/IEC 7498-1 terms
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
___________
A newer edition of this standard has been published, but only the cited edition applies.

61158-5-2 © IEC:2010(E) – 11 –
3.2 ISO/IEC 8822 terms
a) abstract syntax
b) presentation context
3.3 ISO/IEC 9545 terms
a) application-association
b) application-context
c) application context name
d) application-entity-invocation
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 terms
a) object identifier
b) type
3.5 Type 2 fieldbus data-link layer terms
The following terms, defined in IEC 61158-3-2:2007 and IEC 61158-4-2:2010, apply.
a) DL-time
b) DL-scheduling-policy
c) DLCEP
d) DLC
e) DL-connection-oriented mode
f) DLPDU
g) DLSDU
h) DLSAP
i) fixed tag
j) generic tag
k) link
l) MAC ID
m) network address
n) node address
o) node
p) tag
q) scheduled
r) unscheduled
3.6 Type 2 fieldbus application-layer specific definitions
3.6.1
allocate
take a resource from a common area and assign that resource for the exclusive use of a
specific entity
– 12 – 61158-5-2 © IEC:2010(E)
3.6.2
application
function or data structure for which data is consumed or produced
3.6.3
application objects
multiple object classes that manage and provide a run time exchange of messages across the
network and within the network device
3.6.4
application process
part of a distributed application on a network, which is located on one device and
unambiguously addressed
3.6.5
application process object
component of an application process that is identifiable and accessible through an FAL
application relationship
3.6.6
application process object class
a class of application process objects defined in terms of the set of their network-accessible
attributes and services
3.6.7
application relationship
cooperative association between two or more application-entity-invocations for the purpose of
exchange of information and coordination of their joint operation. This relationship is activated
either by the exchange of application-protocol-data-units or as a result of preconfiguration
activities
3.6.8
application relationship application service element
application-service-element that provides the exclusive means for establishing and
terminating all application relationships
3.6.9
application relationship endpoint
context and behavior of an application relationship as seen and maintained by one of the
application processes involved in the application relationship
NOTE Each application process involved in the application relationship maintains its own application relationship
endpoint.
3.6.10
attribute
description of an externally visible characteristic or feature of an object
NOTE The attributes of an object contain information about variable portions of an object. Typically, they provide
status information or govern the operation of an object. Attributes may also affect the behavior of an object.
Attributes are divided into class attributes and instance attributes.
3.6.11
behavior
indication of how an object responds to particular events
3.6.12
boundary clock
clock with more than a single PTP port, with each PTP port providing access to a separate
PTP communication path
61158-5-2 © IEC:2010(E) – 13 –
NOTE Boundary clocks are used to eliminate fluctuations produced by routers and similar network elements.
3.6.13
class
a set of objects, all of which represent the same kind of system component
NOTE A class is a generalization of an object; a template for defining variables and methods. All objects in a
class are identical in form and behavior, but usually contain different data in their attributes.
3.6.14
class attributes
attribute that is shared by all objects within the same class
3.6.15
class code
unique identifier assigned to each object class
3.6.16
class specific service
service defined by a particular object class to perform a required function which is not
performed by a common service
NOTE A class specific object is unique to the object class which defines it.
3.6.17
client
a) object which uses the services of another (server) object to perform a task
b) initiator of a message to which a server reacts
3.6.18
clock
device providing a measurement of the passage of time since a defined epoch
NOTE There are two types of clocks in IEC 61588:2009, boundary clocks and ordinary clocks.
3.6.19
communication objects
components that manage and provide a run time exchange of messages across the network
EXAMPLES Connection Manager object, Unconnected Message Manager (UCMM) object, and Message Router
object
3.6.20
connection
logical binding between application objects that may be within the same or different devices
NOTE 1 Connections may be either point-to-point or multipoint.
NOTE 2 The logical link between sink and source of attributes and services at different custom interfaces of RT-
Auto ASEs is referred to as interconnection. There is a distinction between data and event interconnections. The
logical link and the data flow between sink and source of automation data items is referred to as data
interconnection. The logical link and the data flow between sink (method) and source (event) of operational
services is referred to as event interconnection.
3.6.21
connection ID (CID)
identifier assigned to a transmission that is associated with a particular connection between
producers and consumers, providing a name for a specific piece of application information
3.6.22
connection path
an octet stream that defines the application object to which a connection instance applies

– 14 – 61158-5-2 © IEC:2010(E)
3.6.23
connection point
buffer which is represented as a subinstance of an Assembly object
3.6.24
consume
act of receiving data from a producer
3.6.25
consumer
node or sink that is receiving data from a producer
3.6.26
consuming application
application that consumes data
3.6.27
cyclic
repetitive in a regular manner
3.6.28
device
physical hardware connected to the link
NOTE A device may contain more than one node.
3.6.29
device profile
a collection of device dependent information and functionality providing consistency between
similar devices of the same device type
3.6.30
end node
producing or consuming node
3.6.31
endpoint
one of the communicating entities involved in a connection
3.6.32
epoch
reference time defining the origin of a time scale
[IEC 61588:2009]
3.6.33
error
discrepancy between a computed, observed or measured value or condition and the specified
or theoretically correct value or condition
3.6.34
event
an instance of a change of conditions
3.6.35
frame
denigrated synonym for DLPDU
61158-5-2 © IEC:2010(E) – 15 –
3.6.36
grandmaster clock
clock which serve as the primary source of time to which all others (within a collection of
IEC 61588 clocks) are ultimately synchronized.
3.6.37
group
a) a general term for a collection of objects. Specific uses:
b) when describing an address, an address that identifies more than one entity
3.6.38
interface
(a) shared boundary between two functional units, defined by functional characteristics, signal
characteristics, or other characteristics as appropriate
(b) collection of FAL class attributes and services that represents a specific view on the FAL
class
3.6.39
invocation
act of using a service or other resource of an application process
NOTE Each invocation represents a separate thread of control that may be described by its context. Once the
service completes, or use of the resource is released, the invocation ceases to exist. For service invocations, a
service that has been initiated but not yet completed is referred to as an outstanding service invocation. Also for
service invocations, an Invoke ID may be used to unambiguously identify the service invocation and differentiate it
from other outstanding service invocations.
3.6.40
instance
the actual physical occurrence of an object within a class that identifies one of many objects
within the same object class
EXAMPLE California is an instance of the object class state.
NOTE The terms object, instance, and object instance are used to refer to a specific instance.
3.6.41
instance attributes
attribute that is unique to an object instance and not shared by the object class
3.6.42
instantiated
object that has been created in a device
3.6.43
logical device
a certain FAL class that abstracts a software component or a firmware component as an
autonomous self-contained facility of an automation device
3.6.44
Lpacket (or Link packet)
a piece of application information that contains a size, control octet, tag, and link data
NOTE Peer data-link layers use Lpackets to send and receive service data units from higher layers in the OSI
stack.
3.6.45
management information
network-accessible information that supports managing the operation of the fieldbus system,
including the application layer
NOTE Managing includes functions such as controlling, monitoring, and diagnosing.

– 16 – 61158-5-2 © IEC:2010(E)
3.6.46
master clock
single clock which serves as the primary source of time within each region, and which will in
turn synchronize to other master clocks and ultimately to the grandmaster clock
NOTE A system of IEC 61588 clocks may be segmented into regions separated by boundary clocks.
3.6.47
member
piece of an attribute that is structured as an element of an array
3.6.48
Message Router
object within a node that distributes messaging requests to appropriate application objects
3.6.49
method
a synonym for an operational service which is provided by the server ASE and
invoked by a client
3.6.50
module
hardware or logical component of a physical device
3.6.51
multipoint connection
connection from one node to many
NOTE Multipoint connections allow messages from a single producer to be received by many consumer nodes.
3.6.52
network
a set of nodes connected by some type of communication medium, including any intervening
repeaters, bridges, routers and lower-layer gateways
3.6.53
object
abstract representation of a particular component within a device, usually a collection of
related data (in the form of variables) and methods (procedures) for operating on that data
that have clearly defined interface and behavior
3.6.54
object specific service
service unique to the object class which defines it
3.6.55
ordinary clock
IEC 61588 clock with a single PTP port
3.6.56
originator
client responsible for establishing a connection path to the target
3.6.57
peer
role of an AR endpoint in which it is capable of acting as both client and server
3.6.58
physical device
an automation or other network device

61158-5-2 © IEC:2010(E) – 17 –
3.6.59
point-to-point connection
connection that exists between exactly two application objects
3.6.60
Precision Time Protocol (PTP)
name used for the time synchronization protocol.
3.6.61
produce
act of sending data to be received by a consumer
3.6.62
producer
node that is responsible for sending data
3.6.63
property
general term for descriptive information about an object
3.6.64
PTP message
IEC 61588 time synchronization message
NOTE There are five designated messages types defined by IEC 61588:2009: Sync, Delay_Req, Follow-up,
Delay_Resp, and Management.
3.6.65
PTP port
logical access point for IEC 61588 communications to the clock containing the port
3.6.66
resource
a processing or information capability of a subsystem
3.6.67
serial number
a unique
...