IEC 62769-3:2021
(Main)Field Device Integration (FDI) - Part 3: Server
Field Device Integration (FDI) - Part 3: Server
IEC 62769-3:2021 specifies the FDI Server. The overall FDI architecture is illustrated in Figure 1. The architectural components that are within the scope of this document have been highlighted in this figure.
Intégration des appareils de terrain (FDI) - Partie 3: Serveur
L'IEC 62769-3:2021 spécifie le Serveur FDI. L'architecture FDI complète est représentée à la Figure 1. Les composants architecturaux qui relèvent du domaine d'application du présent document ont été mis en évidence dans cette figure.
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STANDARD
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Field device integration (FDI) –
Part 3: FDI Server
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IEC 62769-3 ®
Edition 2.0 2021-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Field device integration (FDI) –
Part 3: FDI Server
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 25.040.40; 35.100.05 ISBN 978-2-8322-9389-8
– 2 – IEC 62769-3:2021 RLV © IEC 2021
CONTENTS
FOREWORD . 5
INTRODUCTION . 2
1 Scope . 9
2 Normative references . 9
3 Terms, definitions, abbreviated terms and acronyms conventions . 10
3.1 Terms and definitions . 10
3.2 Abbreviated terms and acronyms . 11
3.3 Conventions . 11
4 Overview . 11
5 Information Model . 12
5.1 General . 12
5.2 Online/Offline . 12
5.2.1 Overview . 12
5.2.2 Transfer to device . 13
5.2.3 Transfer from device . 13
5.3 Access privileges . 13
5.4 Private Parameters . 13
5.5 Locking . 14
5.6 EditContext . 15
5.6.1 Concept and usage model . 15
5.6.2 Services . 16
5.6.3 NodeIds . 16
5.6.4 Reading . 17
5.6.5 Writing . 17
5.6.6 Writing dominant and dependent Variables . 17
5.6.7 Actions (EDD METHODS) . 17
5.6.8 UIDs . 20
5.6.9 Synchronization . 20
5.7 Reading . 20
5.7.1 General . 20
5.7.2 Reading offline variables . 21
5.7.3 Reading online variables . 21
5.8 Writing . 22
5.8.1 General . 22
5.8.2 Write offline variables . 23
5.8.3 Writing online variables . 24
5.8.4 Writing to an EditContext . 26
5.9 Subscription . 27
5.9.1 General . 27
5.9.2 Subscription of offline variables . 27
5.9.3 Subscription of online variables . 28
5.10 Device topology . 30
5.10.1 General . 30
5.10.2 Connection Points . 30
5.10.3 Topology management . 31
5.10.4 Topology scanning . 34
5.10.5 Use of SCAN function . 35
5.10.6 Validation of defined topology . 35
5.11 User Interface Elements . 36
5.11.1 User Interface Descriptions. 36
5.11.2 User Interface Plug-ins . 37
5.12 Actions . 37
5.12.1 FDI Server – FDI Client interaction . 37
5.12.2 Action state machine . 40
5.12.3 Actions Proxies . 42
5.12.4 Actions, EDD Actions and Actions Proxies . 42
6 OPC UA services . 44
6.1 OPC UA profiles . 44
6.2 Service error information . 44
6.2.1 Overview . 44
6.2.2 OPC UA services and their response . 44
6.2.3 Mappings of EDDL response codes to OPC UA service response . 44
6.3 Parameter value update during write service request . 45
6.4 Localization . 46
6.5 Audit events . 46
7 Communication . 46
7.1 Notation . 46
7.2 General . 46
7.2.1 Concepts . 46
7.2.2 Terms . 49
7.3 Communication Service processing . 50
7.3.1 Communication Service invocation . 50
7.3.2 Analyze communication path . 50
7.3.3 Manage communication relations . 51
7.3.4 Communication service request mapping . 51
7.3.5 Communication service request propagation . 52
7.3.6 Communication error handling . 53
7.4 FDI Communication Server specific handling . 53
7.4.1 Discovery . 53
7.4.2 Information Model synchronization . 54
8 Parallel Execution within the FDI Server . 54
8.1 Motivation . 54
8.2 Internal structure of the EDD interpreter. 54
8.3 Rules for running an EDD entity . 55
Annex A (informative) FDI Server functional structure . 56
A.1 FDI functional elements . 56
A.2 FDI Server extension . 57
Annex B (informative) Access privileges and user roles . 59
B.1 User roles and usage case . 59
B.2 Private data usage . 60
Annex C (informative) Parallel execution within the FDI Server – Examples . 61
C.1 Simple example for a synchronous execution . 61
C.2 Example for a concurrent execution . 61
C.3 Deadlock detection in concurrent execution . 63
– 4 – IEC 62769-3:2021 RLV © IEC 2021
Figure 1 – FDI architecture diagram . 9
Figure 2 – Locking services . 14
Figure 3 – EditContext models . 15
Figure 4 – Online EditContext state diagram for dominant and dependent Variables . 18
Figure 5 – Offline EditContext state diagram for dominant and dependent Variables . 19
Figure 6 – EditContext for EDD Methods . 19
Figure 7 – Offline variable read . 21
Figure 8 – Online variable read . 22
Figure 9 – Offline variable write immediate . 23
Figure 10 – Online variable write immediate . 25
Figure 11 – Write with EditContext . 26
Figure 12 – Offline variable subscription . 28
Figure 13 – Online variable subscription . 29
Figure 14 – Topology with Network objects (non-normative) . 30
Figure 15 – Add Device to topology . 32
Figure 16 – Remove device from topology . 33
Figure 17 – Scan topology . 34
Figure 18 – Action execution . 39
Figure 19 – Action state machine . 40
Figure 20 – System communication integration example . 47
Figure 21 – FDI Communication Server integration example . 48
Figure 22 – Gateway integration example . 49
Figure 23 – Message propagation example scenario . 52
Figure A.1 – Functional components of an FDI Server . 56
Figure A.2 – FDI Server extensions . 58
Figure B.1 – User roles and access privileges . 59
Figure C.1 – Synchronous execution of two triggers . 61
Figure C.2 – Concurrent execution of two triggers (step 1) . 61
Figure C.3 – Concurrent execution of two triggers (step 2) . 62
Figure C.4 – Concurrent execution of two triggers (step 3) . 62
Figure C.5 – Concurrent execution of two triggers (step 4) . 63
Figure C.6 – Concurrent execution of two triggers. 63
Table 1 – Action states . 40
Table 2 – Action state transitions . 41
Table 3 – EDD Action types and the EDD constructs that use them . 43
Table 4 – OPC UA severity bits and EDDL response codes TYPE . 45
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIELD DEVICE INTEGRATION (FDI) –
Part 3: FDI Server
FOREWORD
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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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.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition IEC 62769-3:2015. A vertical bar appears in the margin
wherever a change has been made. Additions are in green text, deletions are in
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– 6 – IEC 62769-3:2021 RLV © IEC 2021
International Standard IEC 62769-3 has been prepared by subcommittee 65E: Devices and
integration in enterprise systems, of IEC technical committee 65: Industrial-process
measurement, control and automation.
This second edition cancels and replaces the first edition published in 2015. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) modification of the edit context concept to harmonize the IEC 61804 and the IEC 62769
series.
The text of this International Standard is based on the following documents:
FDIS Report on voting
65E/760/FDIS 65E/770/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 document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62769 series, published under the general title Field Device
Integration (FDI), can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this 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.
INTRODUCTION
The International Electrotechnical Commission (IEC) draws attention to the fact that it is claimed
that compliance with this document may involve the use of patents concerning
a) method for the Supplying and Installation of Device-Specific Functionalities, see Patent
Family DE10357276;
b) method and device for accessing a functional module of automation system, see Patent
Family EP2182418;
c) methods and apparatus to reduce memory requirements for process control system software
applications, see Patent Family US2013232186;
d) extensible device object model, see Patent Family US12/893,680.
IEC takes no position concerning the evidence, validity and scope of this patent right.
The holders of these patent rights have assured the IEC that he/she is willing to negotiate
licences either free of charge or under reasonable and non-discriminatory terms and conditions
with applicants throughout the world. In this respect, the statement of the holder of this patent
right is registered with IEC. Information may be obtained from:
a) ABB Research Ltd
Claes Rytoft
Affolterstrasse 4
Zurich, 8050
Switzerland
b) Phoenix Contact GmbH & Co KG
Intellectual Property, Licenses & Standards
Flachsmarktstrasse 8, 32825 Blomberg
Germany
c) Fisher Controls International LLC
John Dilger, Emerson Process Management LLLP
st
301 S. 1 Avenue, Marshaltown, Iowa 50158
USA
d) Rockwell Automation Technologies, Inc.
1 Allen-Bradley Drive
Mayfield Heights, Ohio 44124
USA
Attention is drawn to the possibility that some of the elements of this document may be the
subject of patent rights other than those identified above. IEC shall not be held responsible for
identifying any or all such patent rights.
ISO (www.iso.org/patents) and IEC (http://patents.iec.ch) maintain on-line data bases of
patents relevant to their standards. Users are encouraged to consult the data bases for the
most up to date information concerning patents.
The IEC 62769 series has the general title Field Device Integration (FDI) and the following
parts:
– Part 1: Overview
– Part 2: FDI Client
– Part 3: FDI Server
– Part 4: FDI Packages
– Part 5: FDI Information Model
– Part 6: FDI Technology Mapping
– Part 7: FDI Communication Devices
– 8 – IEC 62769-3:2021 RLV © IEC 2021
– Part 100: Profiles – Generic Protocol Extensions
– Part 101-1: Profiles – Foundation Fieldbus H1
– Part 101-2: Profiles – Foundation Fieldbus HSE
– Part 103-1: Profiles – PROFIBUS
– Part 103-4: Profiles – PROFINET
– Part 109-1: Profiles – HART and WirelessHART
– Part 115-2: Profiles – Protocol-specific Definitions for Modbus RTU
– Part 150-1: Profiles – ISA 100.11a
FIELD DEVICE INTEGRATION (FDI) –
Part 3: FDI Server
1 Scope
This part of IEC 62769 specifies the FDI Server. The overall FDI architecture is illustrated in
Figure 1. The architectural components that are within the scope of this document have been
highlighted in this figure.
Figure 1 – FDI architecture diagram
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.
IEC 61804 (all parts), Function blocks (FB) for process control and electronic device description
language (EDDL)
– 10 – IEC 62769-3:2021 RLV © IEC 2021
IEC 61804-3 , Function block (FB) for process control and Electronic Device Description
Language (EDDL) – Part 3: EDDL syntax and semantics
IEC 61804-4 , Function blocks (FB) for process control and Electronic Device Description
Language (EDDL) – Part 4: EDD interpretation
IEC 61804-4:2020, Function blocks (FB) for process control and electronic device description
language (EDDL) – Part 4: EDD interpretation
IEC 62541 (all parts), OPC unified architecture
IEC 62541-4, OPC unified architecture – Part 4: Services
IEC 62541-7, OPC unified architecture – Part 7: Profiles
IEC 62769-1, Field Device Integration (FDI) – Part 1: Overview
NOTE IEC 62769-1 is technically identical to FDI-2021.
IEC 62769-2, Field Device Integration (FDI) – Part 2: FDI Client
NOTE IEC 62769-2 is technically identical to FDI-2022.
IEC 62769-4, Field Device Integration (FDI) – Part 4: FDI Packages
NOTE IEC 62769-4 is technically identical to FDI-2024.
IEC 62769-5, Field Device Integration (FDI) – Part 5: FDI Information Model
NOTE IEC 62769-5 is technically identical to FDI-2025.
IEC 62769-7, Field Device Integration (FDI) – Part 7: FDI Communication Devices
NOTE IEC 62769-7 is technically identical to FDI-2027.
3 Terms, definitions, abbreviated terms and acronyms conventions
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62769-1 as well as
the following 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
3.1.1
Actions Proxy
internal FDI Server entity that encapsulates all the EDD Methods specified in an EDD Action
definition
—————————
To be published.
To be published.
3.2 Abbreviated terms and acronyms
For the purposes of this document, the abbreviated terms and acronyms given in IEC 62769-1
apply.
3.3 Conventions
For the purposes of this document, the conventions given in IEC 62769-1 apply.
4 Overview
The structure for an FDI Server is shown in Figure 1.
FDI Servers that support connectivity with third-party FDI Clients shall support OPC UA. A
vendor can provide both an FDI Server and one or more FDI Clients. In this case, the FDI
Clients can communicate with the FDI Server through proprietary protocols.
An FDI Server communicates with devices via Native Communication (see 7.2.1) and/or
Communication Devices (see IEC 62769-7).
An FDI Server provides information to FDI Clients through an Information Model (see
IEC 62769-5) as follows.
• The Information Model includes information about Device Types and Device Instances. The
information for a Device Instance includes offline data (engineering data), as well as online
data (values from the physical device).
• The Information Model is created using information from FDI Packages. However, not all of
the information in an FDI Package is reflected in the Information Model.
• Referential integrity of the Information Model is maintained using information from FDI
Packages.
• FDI Packages can contain Attachments that contain device manuals and protocol-specific
information (see IEC 62769-4). Those Attachments, including device manuals and protocol-
specific support files, are exposed via the Information Model.
• FDI Device Packages contain information about device types (see
IEC 62769-4). Each device type defined in a package is mapped to a distinct DeviceType
node in the Information Model.
• FDI Profile Packages are used to provide interaction with devices for which an FDI Device
Package does not exist (see IEC 62769-4).
• Multiple revisions of an FDI Package generate distinct DeviceType nodes in the Information
Model (see IEC 62769-4).
FDI Packages contain digital signatures that allow an FDI Server to authenticate their contents
(see IEC 62769-4). An FDI Server shall not use an FDI Package if the digital signature provided
by the FDI Package is invalid.
An FDI Server shall verify the FDI Technology Version (see IEC 62769-1) of any FDI Package
it uses to ensure the FDI Package is compatible with the FDI Server.
The resulting functional structure of an FDI server is described in Annex A.
– 12 – IEC 62769-3:2021 RLV © IEC 2021
5 Information Model
5.1 General
The FDI Server shall use the Device Definition of an FDI Package to maintain the Information
Model.
The Device Definition can contain conditional expressions. Conditional expressions are used
when a certain aspect of the Device Definition is not static but rather is dependent on the state
of the device. Whenever the online or offline values of a Device Instance are modified, the FDI
Server shall re-evaluate the relevant conditional expressions and modify the Information Model
accordingly.
The evaluation of conditional expressions can invalidate variables in the Information Model.
The FDI Server shall change the AccessLevel attribute of invalidated variables such that they
are neither readable nor writable and the status of these variables shall be set to bad. Read
and write service requests for invalidated variables shall return a failure.
The Device Definition can specify relationships between variables in a device. These
relationships can impact the value of variables in the Information Model.
The FDI Server shall generate DataChange Notifications to any FDI Clients that are subscribing
to Information Model elements that have changed.
FDI Packages provide Business Logic that is used by the FDI Server to maintain the integrity
of the Information Model. The Business Logic specified in an FDI Package can invoke builtin
functions that shall be implemented by the FDI Server. The builtin functions that shall be
implemented by the FDI Server are specified in IEC 61804-5.
5.2 Online/Offline
5.2.1 Overview
The Information Model maintained by the FDI Server contains online and offline values. The
online values reflect values in a physical component/device. The offline values reflect values
stored in a configuration database.
The offline values are updated through write service requests from an FDI Client or Business
Logic executed by the FDI Server. The offline values are not updated when the FDI Server
reads data from the device or writes data to the device.
The online values in the Information Model are not updated through write service requests.
Successful write service requests through the Information Model result in value changes in the
physical devices. The online values in the Information Model will then be updated as a result of
read service requests or subscriptions.
FDI Servers can provide a server-specific mechanism for creating Device Instances without the
presence of physical hardware. The FDI Server creates these instances using information in
FDI Packages. All read/write requests for online values for Device Instances with no physical
device shall return an error.
The transfer of information between the offline values and the physical device is supported
through the TransferToDevice and TransferFromDevice methods in the Information Model.
These Methods shall implement the download and upload procedures, respectively, as specified
in IEC 61804-4. When no implementation is provided based on IEC 61804-4, then these
Methods shall return Bad_NotSupported, as per IEC 62541-4.
The Device shall have been locked prior to invoking these methods, as specified in IEC 62769-
5.
5.2.2 Transfer to device
The TransferToDevice method shall implement the download procedure as specified in
IEC 61804-4. This transfers the offline values to the physical device.
As a general rule, the FDI Server should not change the Online variable node when writing a
value to the device. The Online variable node should be updated only in the process of read
operations or subscriptions. Notwithstanding, as specified in IEC 62769-5, the FDI Server will
reset any cached Value for the target Nodes in the Information Model so that they will be re-
read next time they are requested.
The status information returned for each variable included in the write service request is used
to compose the TransferResult, as specified in IEC 62769-5.
5.2.3 Transfer from device
The TransferFromDevice method shall implement the upload procedure as specified in
IEC 61804-4. This transfers the values from the physical device to the offline values.
If any read operations from the device fail during upload, the corresponding offline value shall
not be modified.
The status information returned for each variable included in the read service request is used
to compose the TransferResult, as specified in IEC 62769-5.
5.3 Access privileges
Systems implement security and access policies based on a number of characteristics such as
user role and plant area. FDI Servers use these policies, along with information in FDI
Packages, to determine the access privileges granted to the user.
The elements of an FDI Package can be associated with one or more usage attributes. The FDI
Server uses these attributes to set the UserAccessLevel attribute of Variables and the
UserExecutable attribute of Methods. The usage attributes in an FDI Package are simply hints
to be used by the FDI Server, i.e., they may be disregarded or overridden by the FDI Server.
See also Annex B.
5.4 Private Parameters
The Parameters and Actions specified in an FDI Package may be declared private. Private
Parameters and Actions shall not be browsable; they shall only be accessible through
references from other elements of an FDI Package.
More specifically, the FDI Server shall support private Parameters and Actions as follows.
• The FDI Server shall create nodes in the Information Model for the private Parameters and
Actions.
• The FDI Server shall not include information about private Parameters and Actions in a
response to a Browse, BrowseNext, QueryFirst, or QueryNext service request.
• The FDI Server shall return the NodeIds of private Parameters and Actions when the name
of a private Parameter or Action is passed to TranslateBrowsePathsToNodeIds.
• The FDI Server shall process a read/write service request for a private Parameter in the
same way as it does for public (browsable) Parameters (see 5.7 and 5.8).
– 14 – IEC 62769-3:2021 RLV © IEC 2021
• The FDI Server shall execute private Actions in the same way as it does public (browsable)
Actions (see 5.12).
An example of private parameters is parameters that should only be modified through an Action.
These parameters should not be visible to FDI Clients to prevent direct access. FDI Clients
invoke Actions to access these private parameters.
5.5 Locking
The FDI Server provides locking services to grant FDI Clients exclusive access to Device and
Network elements in the Information Model. The locking services consist of a set of Methods
and status information. The methods, and their behavior, are specified in IEC 62769-5.
The following behavior shall be implemented by the FDI Server to support locks.
• Locking applies to both online and offline nodes.
• Once locked by one FDI Client, any attempt to write to a Parameter or to execute an Action
by another FDI Client shall be rejected.
• Locking is not required for read services.
• Parameters that are locked by one FDI Client can still be read by other FDI Clients, i.e.,
read requests on a Parameter that is locked are not rejected.
Internal use of the locking mechanism for maintaining the Information Model integrity is FDI
Server vendor-specific.
Figure 2 illustrates a locking sequence with multiple service invocations during the locked state.
Figure 2 – Locking services
A service request that requires locking shall fail either partially or completely if no lock has been
acquired by the FDI Client via InitLock prior to requesting the service. The FDI Client has to
release the lock via ExitLock after all service requests have been completed.
NOTE A write operation will partially fail, i.e., it will return a status code for each variable in the
set of variables to be written since some may belong to devices that are locked and some to
devices that are not locked.
FDI Servers may queue InitLock requests until a service for which a lock has been created
completes and the lock has been released. However, such an optimization is not part of the
standard behavior required of an FDI Server.
5.6 EditContext
5.6.1 Concept and usage model
The FDI Server provides the EditContext model to interact with Clients during their editing task.
The concept is closely related to UIDs and fulfills the needs for Server-driven UI dialogs based
on EDDL rules.
An EditContext can be used to make changes to Variable Values visible to the Server without
applying them to the online or offline representation of a Device. The Server will apply business
logic associated to the edited Variable, which – in some cases – causes changes to other
Variable Values (e.g. if an engineering unit is changed) or the UID (e.g. a Variable becomes
invisible). Thus, the Client can use an EditContext to modify (edit) Parameters such as
engineering units, ranges and more, verify any side effects, and re-adjust the settings before
applying the changes.
An FDI Server may implement different EditContext strategies:
• A single EditContext instance for all dialogues of an FDI Client.
• Multiple EditContext instances.
• Hierarchical EditContext instances.
Figure 3 – EditContext models
Figure 3 shows two possible Server strategies and how the Client can adapt. In the lower
scenario, the Server provides a single EditContext instance for all dialogs. Here, the Client
– 16 – IEC 62769-3:2021 RLV © IEC 2021
groups all dialogs and exposes a single set of buttons to Apply and Cancel, because it always
concerns all edits.
In the upper scenario, the Server provides multiple EditContext instances, one of them as child
of another one. Each instance can be addressed separately. If the changes in a child instance
are applied, they are transferred to the parent. If the changes in a root instance are applied,
they are transferred to the Device.
Parent-child dependencies:
• A change for a Variable in the parent overwrites an edited Value for the same Variable
in the Client.
• The parent cannot be discarded before the child is discarded but the edited Values in
the parent instance can be applied or reset.
The parent-child dependencies are defined in IEC 61804-4:2020, Clause 8.
5.6.2 Services
A set of Services is provided to the FDI Client to maintain EditContext instances (see
IEC 62769-5 for a detailed description of these Services):
• GetContext – This Service is used to request an EditContext instance. The Client specifies
certain characteristics for the Server to decide which EditContext instance to return.
Depending on its internal strategy, the Server returns the same instance or new instances.
• RegisterNodes – The FDI Client has to register all Nodes of the Information Model that shall
be maintained in an EditContext. It is possible to register Nodes of the online and of the
offline representation of a Device. The result is new NodeIds that the Client shall use when
calling Services to read, write, subscribe to Variables or to invoke Actions.
• Apply – Transfer the modified (edited) Variable Values to the parent (either a parent
EditContext instance or the Device). If the same Variable has been edited in the parent
instance it will be overwritten with a call of the Apply Service for the child.
• Reset – Clears all modificatio
...
IEC 62769-3 ®
Edition 2.0 2021-02
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Field device integration (FDI) –
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IEC 62769-3 ®
Edition 2.0 2021-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Field device integration (FDI) –
Part 3: Server
Intégration des appareils de terrain (FDI) –
Partie 3: Serveur
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040.40; 35.100.05 ISBN 978-2-8322-9310-2
– 2 – IEC 62769-3:2021 © IEC 2021
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions, abbreviated terms and conventions . 9
3.1 Terms and definitions . 9
3.2 Abbreviated terms . 9
3.3 Conventions . 9
4 Overview . 9
5 Information Model . 10
5.1 General . 10
5.2 Online/Offline . 11
5.2.1 Overview . 11
5.2.2 Transfer to device . 11
5.2.3 Transfer from device . 11
5.3 Access privileges . 12
5.4 Private Parameters . 12
5.5 Locking . 12
5.6 EditContext . 13
5.6.1 Concept and usage model . 13
5.6.2 Services . 14
5.6.3 NodeIds . 15
5.6.4 Reading . 15
5.6.5 Writing . 15
5.6.6 Writing dominant and dependent Variables . 15
5.6.7 Actions (EDD METHODS) . 17
5.6.8 UIDs . 18
5.6.9 Synchronization . 18
5.7 Reading . 18
5.7.1 General . 18
5.7.2 Reading offline variables . 19
5.7.3 Reading online variables . 19
5.8 Writing . 20
5.8.1 General . 20
5.8.2 Write offline variables . 21
5.8.3 Writing online variables . 22
5.8.4 Writing to an EditContext . 24
5.9 Subscription . 25
5.9.1 General . 25
5.9.2 Subscription of offline variables . 25
5.9.3 Subscription of online variables . 26
5.10 Device topology . 28
5.10.1 General . 28
5.10.2 Connection Points . 28
5.10.3 Topology management . 29
5.10.4 Topology scanning . 32
5.10.5 Use of SCAN function . 33
5.10.6 Validation of defined topology . 34
5.11 User Interface Elements . 34
5.11.1 User Interface Descriptions. 34
5.11.2 User Interface Plug-ins . 35
5.12 Actions . 35
5.12.1 FDI Server – FDI Client interaction . 35
5.12.2 Action state machine . 38
5.12.3 Actions Proxies . 40
5.12.4 Actions, EDD Actions and Actions Proxies . 40
6 OPC UA services . 42
6.1 OPC UA profiles . 42
6.2 Service error information . 42
6.2.1 Overview . 42
6.2.2 OPC UA services and their response . 42
6.2.3 Mappings of EDDL response codes to OPC UA service response . 42
6.3 Parameter value update during write service request . 43
6.4 Localization . 44
6.5 Audit events . 44
7 Communication . 44
7.1 Notation . 44
7.2 General . 44
7.2.1 Concepts . 44
7.2.2 Terms . 47
7.3 Communication Service processing . 48
7.3.1 Communication Service invocation . 48
7.3.2 Analyze communication path . 48
7.3.3 Manage communication relations . 49
7.3.4 Communication service request mapping . 49
7.3.5 Communication service request propagation . 50
7.3.6 Communication error handling . 51
7.4 FDI Communication Server specific handling . 51
7.4.1 Discovery . 51
7.4.2 Information Model synchronization . 52
8 Parallel Execution within the FDI Server . 52
8.1 Motivation . 52
8.2 Internal structure of the EDD interpreter. 52
8.3 Rules for running an EDD entity . 53
Annex A (informative) FDI Server functional structure . 54
A.1 FDI functional elements . 54
A.2 FDI Server extension . 55
Annex B (informative) Access privileges and user roles . 57
B.1 User roles and usage case . 57
B.2 Private data usage . 58
Annex C (informative) Parallel execution within the FDI Server – Examples . 59
C.1 Simple example for a synchronous execution . 59
C.2 Example for a concurrent execution . 59
C.3 Deadlock detection in concurrent execution . 61
– 4 – IEC 62769-3:2021 © IEC 2021
Figure 1 – FDI architecture diagram . 8
Figure 2 – Locking services . 13
Figure 3 – EditContext models . 14
Figure 4 – Online EditContext state diagram for dominant and dependent Variables . 16
Figure 5 – Offline EditContext state diagram for dominant and dependent Variables . 17
Figure 6 – EditContext for EDD Methods . 17
Figure 7 – Offline variable read . 19
Figure 8 – Online variable read . 20
Figure 9 – Offline variable write immediate . 21
Figure 10 – Online variable write immediate . 23
Figure 11 – Write with EditContext . 24
Figure 12 – Offline variable subscription . 26
Figure 13 – Online variable subscription . 27
Figure 14 – Topology with Network objects (non-normative) . 28
Figure 15 – Add Device to topology . 30
Figure 16 – Remove device from topology . 31
Figure 17 – Scan topology . 32
Figure 18 – Action execution . 37
Figure 19 – Action state machine . 38
Figure 20 – System communication integration example . 45
Figure 21 – FDI Communication Server integration example . 46
Figure 22 – Gateway integration example . 47
Figure 23 – Message propagation example scenario . 50
Figure A.1 – Functional components of an FDI Server . 54
Figure A.2 – FDI Server extensions . 56
Figure B.1 – User roles and access privileges . 57
Figure C.1 – Synchronous execution of two triggers . 59
Figure C.2 – Concurrent execution of two triggers (step 1) . 59
Figure C.3 – Concurrent execution of two triggers (step 2) . 60
Figure C.4 – Concurrent execution of two triggers (step 3) . 60
Figure C.5 – Concurrent execution of two triggers (step 4) . 61
Figure C.6 – Concurrent execution of two triggers. 61
Table 1 – Action states . 38
Table 2 – Action state transitions . 39
Table 3 – EDD Action types and the EDD constructs that use them . 41
Table 4 – OPC UA severity bits and EDDL response codes TYPE . 43
INTERNATIONAL ELECTROTECHNICAL COMMISSION
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FIELD DEVICE INTEGRATION (FDI) –
Part 3: Server
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.
International Standard IEC 62769-3 has been prepared by subcommittee 65E: Devices and
integration in enterprise systems, of IEC technical committee 65: Industrial-process
measurement, control and automation.
This second edition cancels and replaces the first edition published in 2015. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) modification of the edit context concept to harmonize the IEC 61804 and the IEC 62769
series.
– 6 – IEC 62769-3:2021 © IEC 2021
The text of this International Standard is based on the following documents:
FDIS Report on voting
65E/760/FDIS 65E/770/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 document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62769 series, published under the general title Field Device
Integration (FDI), can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this 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.
INTRODUCTION
The IEC 62769 series has the general title Field Device Integration (FDI) and the following
parts:
– Part 1: Overview
– Part 2: FDI Client
– Part 3: FDI Server
– Part 4: FDI Packages
– Part 5: FDI Information Model
– Part 6: FDI Technology Mapping
– Part 7: FDI Communication Devices
– Part 100: Profiles – Generic Protocol Extensions
– Part 101-1: Profiles – Foundation Fieldbus H1
– Part 101-2: Profiles – Foundation Fieldbus HSE
– Part 103-1: Profiles – PROFIBUS
– Part 103-4: Profiles – PROFINET
– Part 109-1: Profiles – HART and WirelessHART
– Part 115-2: Profiles – Protocol-specific Definitions for Modbus RTU
– Part 150-1: Profiles – ISA 100.11a
– 8 – IEC 62769-3:2021 © IEC 2021
FIELD DEVICE INTEGRATION (FDI) –
Part 3: Server
1 Scope
This part of IEC 62769 specifies the FDI Server. The overall FDI architecture is illustrated in
Figure 1. The architectural components that are within the scope of this document have been
highlighted in this figure.
Figure 1 – FDI architecture diagram
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.
IEC 61804 (all parts), Function blocks (FB) for process control and electronic device
description language (EDDL)
IEC 61804-4:2020, Function blocks (FB) for process control and electronic device description
language (EDDL) – Part 4: EDD interpretation
IEC 62541-4, OPC unified architecture – Part 4: Services
IEC 62541-7, OPC unified architecture – Part 7: Profiles
IEC 62769-1, Field Device Integration (FDI) – Part 1: Overview
IEC 62769-2, Field Device Integration (FDI) – Part 2: FDI Client
IEC 62769-4, Field Device Integration (FDI) – Part 4: FDI Packages
IEC 62769-5, Field Device Integration (FDI) – Part 5: FDI Information Model
IEC 62769-7, Field Device Integration (FDI) – Part 7: Communication Devices
3 Terms, definitions, abbreviated terms and conventions
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 62769-1 as well as
the following 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
3.1.1
Actions Proxy
internal FDI Server entity that encapsulates all the EDD Methods specified in an EDD Action
definition
3.2 Abbreviated terms
For the purposes of this document, the abbreviated terms given in IEC 62769-1 apply.
3.3 Conventions
For the purposes of this document, the conventions given in IEC 62769-1 apply.
4 Overview
The structure for an FDI Server is shown in Figure 1.
FDI Servers that support connectivity with third-party FDI Clients shall support OPC UA. A
vendor can provide both an FDI Server and one or more FDI Clients. In this case, the FDI
Clients can communicate with the FDI Server through proprietary protocols.
An FDI Server communicates with devices via Native Communication (see 7.2.1) and/or
Communication Devices (see IEC 62769-7).
– 10 – IEC 62769-3:2021 © IEC 2021
An FDI Server provides information to FDI Clients through an Information Model (see
IEC 62769-5) as follows.
• The Information Model includes information about Device Types and Device Instances.
The information for a Device Instance includes offline data (engineering data), as well as
online data (values from the physical device).
• The Information Model is created using information from FDI Packages. However, not all
of the information in an FDI Package is reflected in the Information Model.
• Referential integrity of the Information Model is maintained using information from FDI
Packages.
• FDI Packages can contain Attachments that contain device manuals and protocol-specific
information (see IEC 62769-4). Those Attachments, including device manuals and
protocol-specific support files, are exposed via the Information Model.
• FDI Device Packages contain information about device types (see
IEC 62769-4). Each device type defined in a package is mapped to a distinct DeviceType
node in the Information Model.
• FDI Profile Packages are used to provide interaction with devices for which an FDI Device
Package does not exist (see IEC 62769-4).
• Multiple revisions of an FDI Package generate distinct DeviceType nodes in the
Information Model (see IEC 62769-4).
FDI Packages contain digital signatures that allow an FDI Server to authenticate their
contents (see IEC 62769-4). An FDI Server shall not use an FDI Package if the digital
signature provided by the FDI Package is invalid.
An FDI Server shall verify the FDI Technology Version (see IEC 62769-1) of any FDI Package
it uses to ensure the FDI Package is compatible with the FDI Server.
The resulting functional structure of an FDI server is described in Annex A.
5 Information Model
5.1 General
The FDI Server shall use the Device Definition of an FDI Package to maintain the Information
Model.
The Device Definition can contain conditional expressions. Conditional expressions are used
when a certain aspect of the Device Definition is not static but rather is dependent on the
state of the device. Whenever the online or offline values of a Device Instance are modified,
the FDI Server shall re-evaluate the relevant conditional expressions and modify the
Information Model accordingly.
The evaluation of conditional expressions can invalidate variables in the Information Model.
The FDI Server shall change the AccessLevel attribute of invalidated variables such that they
are neither readable nor writable and the status of these variables shall be set to bad. Read
and write service requests for invalidated variables shall return a failure.
The Device Definition can specify relationships between variables in a device. These
relationships can impact the value of variables in the Information Model.
The FDI Server shall generate DataChange Notifications to any FDI Clients that are
subscribing to Information Model elements that have changed.
FDI Packages provide Business Logic that is used by the FDI Server to maintain the integrity
of the Information Model. The Business Logic specified in an FDI Package can invoke builtin
functions that shall be implemented by the FDI Server. The builtin functions that shall be
implemented by the FDI Server are specified in IEC 61804-5.
5.2 Online/Offline
5.2.1 Overview
The Information Model maintained by the FDI Server contains online and offline values. The
online values reflect values in a physical component/device. The offline values reflect values
stored in a configuration database.
The offline values are updated through write service requests from an FDI Client or Business
Logic executed by the FDI Server. The offline values are not updated when the FDI Server
reads data from the device or writes data to the device.
The online values in the Information Model are not updated through write service requests.
Successful write service requests through the Information Model result in value changes in
the physical devices. The online values in the Information Model will then be updated as a
result of read service requests or subscriptions.
FDI Servers can provide a server-specific mechanism for creating Device Instances without
the presence of physical hardware. The FDI Server creates these instances using information
in FDI Packages. All read/write requests for online values for Device Instances with no
physical device shall return an error.
The transfer of information between the offline values and the physical device is supported
through the TransferToDevice and TransferFromDevice methods in the Information Model.
These Methods shall implement the download and upload procedures, respectively, as
specified in IEC 61804-4. When no implementation is provided based on IEC 61804-4, then
these Methods shall return Bad_NotSupported, as per IEC 62541-4.
The Device shall have been locked prior to invoking these methods, as specified in
IEC 62769-5.
5.2.2 Transfer to device
The TransferToDevice method shall implement the download procedure as specified in
IEC 61804-4. This transfers the offline values to the physical device.
As a general rule, the FDI Server should not change the Online variable node when writing a
value to the device. The Online variable node should be updated only in the process of read
operations or subscriptions. Notwithstanding, as specified in IEC 62769-5, the FDI Server will
reset any cached Value for the target Nodes in the Information Model so that they will be re-
read next time they are requested.
The status information returned for each variable included in the write service request is used
to compose the TransferResult, as specified in IEC 62769-5.
5.2.3 Transfer from device
The TransferFromDevice method shall implement the upload procedure as specified in
IEC 61804-4. This transfers the values from the physical device to the offline values.
If any read operations from the device fail during upload, the corresponding offline value shall
not be modified.
– 12 – IEC 62769-3:2021 © IEC 2021
The status information returned for each variable included in the read service request is used
to compose the TransferResult, as specified in IEC 62769-5.
5.3 Access privileges
Systems implement security and access policies based on a number of characteristics such
as user role and plant area. FDI Servers use these policies, along with information in FDI
Packages, to determine the access privileges granted to the user.
The elements of an FDI Package can be associated with one or more usage attributes. The
FDI Server uses these attributes to set the UserAccessLevel attribute of Variables and the
UserExecutable attribute of Methods. The usage attributes in an FDI Package are simply hints
to be used by the FDI Server, i.e., they may be disregarded or overridden by the FDI Server.
See also Annex B.
5.4 Private Parameters
The Parameters and Actions specified in an FDI Package may be declared private. Private
Parameters and Actions shall not be browsable; they shall only be accessible through
references from other elements of an FDI Package.
More specifically, the FDI Server shall support private Parameters and Actions as follows.
• The FDI Server shall create nodes in the Information Model for the private Parameters and
Actions.
• The FDI Server shall not include information about private Parameters and Actions in a
response to a Browse, BrowseNext, QueryFirst, or QueryNext service request.
• The FDI Server shall return the NodeIds of private Parameters and Actions when the
name of a private Parameter or Action is passed to TranslateBrowsePathsToNodeIds.
• The FDI Server shall process a read/write service request for a private Parameter in the
same way as it does for public (browsable) Parameters (see 5.7 and 5.8).
• The FDI Server shall execute private Actions in the same way as it does public
(browsable) Actions (see 5.12).
An example of private parameters is parameters that should only be modified through an
Action. These parameters should not be visible to FDI Clients to prevent direct access. FDI
Clients invoke Actions to access these private parameters.
5.5 Locking
The FDI Server provides locking services to grant FDI Clients exclusive access to Device and
Network elements in the Information Model. The locking services consist of a set of Methods
and status information. The methods, and their behavior, are specified in IEC 62769-5.
The following behavior shall be implemented by the FDI Server to support locks.
• Locking applies to both online and offline nodes.
• Once locked by one FDI Client, any attempt to write to a Parameter or to execute an
Action by another FDI Client shall be rejected.
• Locking is not required for read services.
• Parameters that are locked by one FDI Client can still be read by other FDI Clients, i.e.,
read requests on a Parameter that is locked are not rejected.
Internal use of the locking mechanism for maintaining the Information Model integrity is FDI
Server vendor-specific.
Figure 2 illustrates a locking sequence with multiple service invocations during the locked
state.
Figure 2 – Locking services
A service request that requires locking shall fail either partially or completely if no lock has
been acquired by the FDI Client via InitLock prior to requesting the service. The FDI Client
has to release the lock via ExitLock after all service requests have been completed.
A write operation will partially fail, i.e., it will return a status code for each variable in the set
of variables to be written since some may belong to devices that are locked and some to
devices that are not locked.
FDI Servers may queue InitLock requests until a service for which a lock has been created
completes and the lock has been released. However, such an optimization is not part of the
standard behavior required of an FDI Server.
5.6 EditContext
5.6.1 Concept and usage model
The FDI Server provides the EditContext model to interact with Clients during their editing
task. The concept is closely related to UIDs and fulfills the needs for Server-driven UI dialogs
based on EDDL rules.
An EditContext can be used to make changes to Variable Values visible to the Server without
applying them to the online or offline representation of a Device. The Server will apply
business logic associated to the edited Variable, which – in some cases – causes changes to
other Variable Values (e.g. if an engineering unit is changed) or the UID (e.g. a Variable
becomes invisible). Thus, the Client can use an EditContext to modify (edit) Parameters such
as engineering units, ranges and more, verify any side effects, and re-adjust the settings
before applying the changes.
An FDI Server may implement different EditContext strategies:
• A single EditContext instance for all dialogues of an FDI Client.
• Multiple EditContext instances.
• Hierarchical EditContext instances.
– 14 – IEC 62769-3:2021 © IEC 2021
Figure 3 – EditContext models
Figure 3 shows two possible Server strategies and how the Client can adapt. In the lower
scenario, the Server provides a single EditContext instance for all dialogs. Here, the Client
groups all dialogs and exposes a single set of buttons to Apply and Cancel, because it always
concerns all edits.
In the upper scenario, the Server provides multiple EditContext instances, one of them as
child of another one. Each instance can be addressed separately. If the changes in a child
instance are applied, they are transferred to the parent. If the changes in a root instance are
applied, they are transferred to the Device.
The parent-child dependencies are defined in IEC 61804-4:2020, Clause 8.
5.6.2 Services
A set of Services is provided to the FDI Client to maintain EditContext instances (see
IEC 62769-5 for a detailed description of these Services):
• GetContext – This Service is used to request an EditContext instance. The Client specifies
certain characteristics for the Server to decide which EditContext instance to return.
Depending on its internal strategy, the Server returns the same instance or new instances.
• RegisterNodes – The FDI Client has to register all Nodes of the Information Model that
shall be maintained in an EditContext. It is possible to register Nodes of the online and of
the offline representation of a Device. The result is new NodeIds that the Client shall use
when calling Services to read, write, subscribe to Variables or to invoke Actions.
• Apply – Transfer the modified (edited) Variable Values to the parent (either a parent
EditContext instance or the Device). If the same Variable has been edited in the parent
instance it will be overwritten with a call of the Apply Service for the child.
• Reset – Clears all modifications. A Reset of already applied modifications is not possible.
• Discard – Deletes an EditContext instance (and its children). Edited Values that have not
been applied are discarded. Once deleted, all registered NodeIds will be invalid. If such
NodeIds are still subscribed, the Client is notified with proper StatusCodes.
The Client first calls GetEditContext to acquire an EditContext instance. It will then register
the Nodes it wants to be part of it. The registration returns new NodeIds which can then be
used for reading, writing or subscribing Variables and for calling Methods.
The Client can call GetEditContext multiple times, for instance when it opens an additional
edit window or for a completely separate dialog (diagnosis in parallel to configuration). It is up
to the Server strategy whether it returns a new instance or the same instance. The Client is
expected to adapt its user interface to the EditContext strategy of the Server. See Figure 3 for
how Clients may position the Apply and Cancel buttons so that the User clearly understands
which changes are applied or discarded.
5.6.3 NodeIds
RegisterNode returns two NodeIds for each registere
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