IEC 61400-25-3:2006

Wind turbines - Part 25-3: Communications for monitoring and control of wind power plants - Information exchange models

Specifies an abstract communication service interface describing the information exchange between a client and a server for: data access and retrieval, device control, event reporting and logging, publisher/subscriber, self-description of devices (device data dictionary), data typing and discovery of data types.
This publication is of high relevance for Smart Grid.

General Information

• Status: Published
• Publication Date: 13-Dec-2006
• ICS: 27.180 - Wind turbine energy systems
• Technical Committee: TC 88 - Wind energy generation systems
• Current Stage: DELPUB - Deleted Publication
• Start Date: 30-Jun-2015
• Completion Date: 26-Oct-2025

Relations

• Revised: IEC 61400-25-3:2015 - Wind turbines - Part 25-3: Communications for monitoring and control of wind power plants - Information exchange models
• Effective Date: 05-Sep-2023

Overview

IEC 61400-25-3:2006 defines the information exchange models for communications used in monitoring and control of wind power plants. Part 25-3 specifies the Abstract Communication Service Interface (ACSI) - a protocol-agnostic, client‑server service model that standardizes how clients (for example SCADA or asset-management systems) and servers (turbine controllers, sub‑systems) exchange data for data access and retrieval, device control, event reporting and logging, publisher/subscriber services, device self‑description (data dictionary), data typing and discovery. The standard is part of the IEC 61400-25 series and is highly relevant to Smart Grid integration and multi‑vendor interoperability.

Key topics and technical requirements

• Abstract Communication Service Interface (ACSI): Defines services and parameters for accessing hierarchical wind power plant information without prescribing the underlying protocol stack (mapping to concrete protocols is in IEC 61400-25-4).
• Information exchange models: Includes class models and services for Server, Logical Device, Logical Node, Data, DataSet, Report Control Block, Log Control Block, Log and Control.
• Operational models: Association & authorization, control model, monitoring/reporting/logging, and publisher/subscriber mechanisms (including buffered reporting and subscriptions).
• Management functions: User management/access security, setup, time synchronization, diagnostics (self‑monitoring) and configuration services.
• Event reporting & logging: Standardized reporting and logging services and control blocks to support event notification, historical logs and buffered reports.
• Data typing & discovery: Self‑description of devices (device data dictionary), data typing and discovery of data types to enable automatic integration and uniform access.

Practical applications

• Enables interoperable SCADA and control-room integration across turbines and components from different vendors.
• Facilitates real‑time monitoring, remote control and automated response for wind farms connecting to Smart Grids.
• Supports condition monitoring, event logging and compliance reporting required by utilities and grid operators.
• Simplifies development of middleware, gateways and protocol mappings (e.g., when implementing IEC 61400-25-4 mappings).
• Useful for integration with data historians, asset management systems, and publisher/subscriber-based telemetry.

Who uses this standard

• Wind turbine OEMs and control-system designers
• SCADA/RTU integrators and system integrators
• Utility grid operators and wind‑farm operators
• Software vendors developing monitoring, logging and asset-management solutions
• Standards bodies and consultants working on Smart Grid interoperability

Related standards

• IEC 61400-25 series (information model: IEC 61400-25-2; protocol mapping: IEC 61400-25-4)
• References and interoperability notes with IEC 61850 series are discussed in annexes for mapping and service relationships.

Keywords: IEC 61400-25-3, wind turbines communication, ACSI, information exchange models, Smart Grid, SCADA integration, monitoring and control, reporting and logging, logical device, publisher/subscriber.

Standards Content (Sample)

INTERNATIONAL IEC
STANDARD 61400-25-3
First edition
2006-12
Wind turbines –
Part 25-3:
Communications for monitoring
and control of wind power plants –
Information exchange models
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INTERNATIONAL IEC
STANDARD 61400-25-3
First edition
2006-12
Wind turbines –
Part 25-3:
Communications for monitoring
and control of wind power plants –
Information exchange models
© IEC 2006 ⎯ Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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For price, see current catalogue

– 2 – 61400-25-3 © IEC:2006(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6

1 Scope.7
2 Normative references .8
3 Terms and definitions .9
4 Abbreviated terms .12
5 General .12
6 Information exchange models overview .13
7 Operational functions .15
7.1 General .15
7.2 Association and authorisation model .15
7.3 Control model.16
7.4 Monitoring, reporting and logging model.16
8 Management functions .18
8.1 General .18
8.2 User management/access security model.18
8.3 Setup model .18
8.4 Time synchronisation model .18
8.5 Diagnostic (self-monitoring) model .18
9 The ACSI for wind power plant information models.19
9.1 General .19
9.2 Services of Association and authorisation .19
9.3 Services of Server class .20
9.4 Services of Logical Device class .20
9.5 Services of Logical Node class.21
9.6 Services of Data class.21
9.7 Services of DataSet class.21
9.8 Services of Report Control Block class .22
9.9 Services of Log Control Block and Log classes .24
9.10 Services of control class.26

Annex A (informative) Examples of reporting and logging services.27
Annex B (normative) Relationship between ACSI Services and Functional Constraints .29
Annex C (informative) Relationship between ACSI defined in IEC 61850-7-2 and
IEC 61400-25-3 .31

Figure 1 – Conceptual communication model of the IEC 61400-25 series .8
Figure 2 – Association and authorisation model (conceptual) .15
Figure 3 – Control model (conceptual) .16
Figure 4 – Monitoring, reporting and logging model (conceptual) .17
Figure 5 – Conceptual information exchange model for a wind power plant.19
Figure 6 – Buffered report control block – conceptual .23
Figure 7 – Log control block – conceptual .26

61400-25-3 © IEC:2006(E) – 3 –
Figure A.1 – Mapping of Information Models to Data Sets for reporting (example) .27
Figure A.2 – Logging basics (example) .28
Figure C.1 – Conceptual service model of the ACSI.32

Table 1 – Information exchange models.14
Table 2 – Comparison of the information retrieval methods.18
Table 3 – Two-Party-Application-Association .20
Table 4 – Server .20
Table 5 – Logical Device.20
Table 6 – Logical Node .21
Table 7 – DATA .21
Table 8 – DATA-SET .21
Table 9 – REPORT-CONTROL .22
Table 10 – AddSubscription service .23
Table 11 – RemoveSubscription service .24
Table 12 – LOG and LOG-CONTROL .25
Table 13 – Data filter .25
Table 14 – CONTROL.26
Table B.1 – Relationship between ACSI Services and Functional Constraints.30

– 4 – 61400-25-3 © IEC:2006(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
WIND TURBINES –
Part 25-3: Communications for monitoring
and control of wind power plants –
Information exchange models
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.
International Standard IEC 61400-25-3 has been prepared by IEC technical committee 88:
Wind turbines.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The text of this standard is based on the following documents:
FDIS Report on voting
88/276/FDIS 88/282/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.
A list of all parts of the IEC 61400 series, under the general title Wind turbines can be found
on the IEC website.
61400-25-3 © IEC:2006(E) – 5 –
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 6 – 61400-25-3 © IEC:2006(E)
INTRODUCTION
The IEC 61400-25 series defines communications for monitoring and control of wind power
plants. The modeling approach of the IEC 61400-25 series has been selected to provide
abstract definitions of classes and services such that the specifications are independent of
specific protocol stacks, implementations, and operating systems. The mapping of these
abstract classes and services to a specific communication profile is not inside the scope of
this part (IEC 61400-25-3) but inside the scope of IEC 61400-25-4 .
This part of IEC 61400-25 defines services of the model of the information exchange of
intelligent electronic devices in wind power plants. The services are referred to as the
Abstract Communication Service Interface (ACSI). The ACSI has been defined so as to be
independent of the underlying communication systems.
The information exchange model is defined in terms of
– a hierarchical class model of all information that can be accessed,
– information exchange services that operate on these classes,
– parameters associated with each information exchange service.
The ACSI description technique abstracts away from all the different approaches to implement
the cooperation of the various devices.
These abstract service definitions shall be mapped into concrete object definitions that are to
be used for a particular protocol. Mapping to specific protocol stacks is specified in
IEC 61400-25-4.
NOTE 1 Abstraction in ACSI has two meanings. Firstly, only those aspects of a real device (for example, a rotor)
or a real function that are visible and accessible over a communication network are modelled. This abstraction
leads to the hierarchical class models and their behaviour defined in IEC 61400-25-2. Secondly, the ACSI abstracts
from the aspect of concrete definitions on how the devices exchange information; only a conceptual cooperation is
defined. The concrete information exchange is defined in IEC 61400-25-4.
NOTE 2 Performance of the IEC 61400-25 series implementations are application specific. The IEC 61400-25
series does not guarantee a certain level of performance. This is beyond the scope of the IEC 61400-25 series.
However, there is no underlying limitation in the communications technology to prevent high speed application
(millisecond level responses).
—————————
To be published.
61400-25-3 © IEC:2006(E) – 7 –
WIND TURBINES –
Part 25-3: Communications for monitoring
and control of wind power plants –
Information exchange models
1 Scope
The focus of the IEC 61400-25 series is on the communications between wind power plant
components such as wind turbines and actors such as SCADA Systems. Internal
communication within wind power plant components is outside the scope of the IEC 61400-25
series.
The IEC 61400-25 series is designed for a communication environment supported by a client-
server model. Three areas are defined, that are modelled separately to ensure the scalability
of implementations: (1) wind power plant information models, (2) information exchange model,
and (3) mapping of these two models to a standard communication profile.
The wind power plant information model and the information exchange model, viewed
together, constitute an interface between client and server. In this conjunction, the wind
power plant information model serves as an interpretation frame for accessible wind power
plant data. The wind power plant information model is used by the server to offer the client a
uniform, component-oriented view of the wind power plant data. The information exchange
model reflects the whole active functionality of the server. The IEC 61400-25 series enables
connectivity between a heterogeneous combination of client and servers from different
manufacturers and suppliers.
As depicted in Figure 1, the IEC 61400-25 series defines a server with the following aspects:
– information provided by a wind power plant component, e. g., “wind turbine rotor speed” or
“total power production of a certain time interval” is modelled and made available for
access. The information modelled in the IEC 61400-25 series is defined in IEC 61400-25-
2;
– services to exchange values of the modelled information defined in part IEC 61400-25-3;
– mapping to a communication profile, providing a protocol stack to carry the exchanged
values from the modelled information (part IEC 61400-25-4).
The IEC 61400-25 series only defines how to model the information, information exchange
and mapping to specific communication protocols. The IEC 61400-25 series excludes a
definition of how and where to implement the communication interface, the application
program interface and implementation recommendations. However, the objective of the IEC
61400-25 series is that the information associated with a single wind power plant component
(such as a wind turbine) is accessible through a corresponding logical device.
This part of IEC 61400-25 specifies an abstract communication service interface describing
the information exchange between a client and a server for:
– data access and retrieval,
– device control,
– event reporting and logging,
– publisher/subscriber,
– self-description of devices (device data dictionary),
– data typing and discovery of data types.

– 8 – 61400-25-3 © IEC:2006(E)

Communication model of the IEC 61400-25 series
Client Server
Messaging
Messaging
Information exchange Information exchange
Information exchange through mapping Information exchange
through mapping
model (get, set, report, model (get, set, report,
model (get, set, report, to communication model (get, set, report,
to communication
log, control, publish / log, control, publish /
log, control, publish / profile (Read, log, control, publish /
profile (Read,
subscribe, etc.) subscribe, etc.)
subscribe, etc.) write, . message) subscribe, etc.)
write, . message)
defined in defined in
defined in defined in defined in
defined in
Wind power
Actor IEC 61400-25-3 IEC 61400-25-3
IEC 61400-25-3 IEC 61400-25-4 IEC 61400-25-3
IEC 61400-25-4 plant
e.g.
SCADA component
e.g. wind turbine
Wind power plant Wind power plant
Wind power plant Wind power plant
information model information model
information model information model
(rotor speed, break
defined in
(rotor speed, break
defined in
status, total power
status, total power
Application IEC 61400-25-2 Application
production, etc.)
IEC 61400-25-2
production, etc.)
defined in
defined in
IEC 61400-25-2
IEC 61400-25-2
Outside
Outside
scope
scope
IEC  2172/06
Figure 1 – Conceptual communication model of the IEC 61400-25 series

2 Normative references
The following referenced documents are indispensable for the application of this part of the
IEC 61400-25 series. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments)
applies.
IEC 61400-25 (all parts), Wind turbines – Part 25: Communications for monitoring and control
of wind power plants
IEC 61850-7-2:2003, Communication networks and systems in substations – Part 7-2: Basic
communication structure for substations and feeder equipment – Abstract communication
service interface (ACSI)
61400-25-3 © IEC:2006(E) – 9 –
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
actor
role a system plays in the context of monitoring and control, while it is not directly involved in
wind power plant operation, such as Supervisory Control and Data Acquisition System
(SCADA)
NOTE There are many other designations, for example, Central Management System, Monitoring and Control
System, Remote Control System.
3.2
alarm
state information. Statement of safety intervention by the wind turbine control system (i.e
on/off)
3.3
command
controllable data for system behaviour (enable/disable, active/deactivate, etc.)
3.4
communication function
used by an actor to configure, perform and monitor the information exchange with wind power
plants, for example operational and management function
3.5
control
operational function used for changing and modifying, intervening, switching, controlling,
parameterisation and optimising of wind power plants
3.6
data retrieval
operational function used for collecting of wind power plant data
3.7
diagnostics
management function used to set up and provide for self-monitoring of the communication
system
3.8
event
state transition (status, alarm, command)
3.9
intelligent Electronic Device
IED
any device incorporating one or more processors, with the capability to receive data from an
external sender or to send data to an external receiver
NOTE For example, wind turbine controller. An IED may have connections as a client, or as a server, or both, with
other IED.
– 10 – 61400-25-3 © IEC:2006(E)
3.10
information
content of communication. Information is defined as data (usually processed and derived
data, and information describing other data). The basic element is raw data from the wind
power plant component, which should be processed into specified information according to
the IEC 61400-25 series
NOTE Wind power plant information categories: source information (analogue and state information), control
information, derived information (statistical and historical information).
3.11
information exchange
communication process between two systems, such as wind power component and actor, with
the goal to provide and to get relevant information. Requires specific communication
functions, consisting of one or more services
3.12
log
historical information. Chronological list of source information for a period of time
3.13
logging
operational function The praxis of recording sequential data often chronologically. The result
of the logging is a log
3.14
logical device
Entity that represent a set of typical wind power plant functions
3.15
management function
function required for the administration of the information exchange in a certain level
NOTE Management functions are user/access management, time synchronisation, diagnostics, and configuration.
3.16
mandatory
defined content shall be provided in compliance with the IEC 61400-25 series
3.17
measured data
sampled value of a process quantity with associated data attributes such as time stamp and
quality
3.18
meteorological system
component of a wind power plant responsible for the monitoring of the ambient conditions, for
example the wind speed, wind direction, pressure, temperature etc. It supplies data for
various purposes for example to correlate the meteorological data to the electrical energy
output by individual wind turbines to the potentially usable wind energy
3.19
monitoring
operational function used for local or remote observation of a system or a process for any
changes which may occur over time. The term can also be used for observation of the
behaviour of a data value or a group of data values

61400-25-3 © IEC:2006(E) – 11 –
3.20
operational function
function to obtain information and to send instructions for the normal daily operation of wind
power plants. Types: monitoring, logging and reporting, data retrieval, control
3.21
optional
defined content can be optionally provided in compliance to the IEC 61400-25 series
3.22
parameter
controllable information intended for obtaining or correcting system behaviour
3.23
processed value
measured value, with the associated data attributes such as time stamp and quality, which
have been processed according the calculation method attribute (10m-average/…)
3.24
report
actual information sent by the function reporting
3.25
reporting
operational function to transfer data from a server to a client, initiated by a server application
process
3.26
Supervisory Control and Data Acquisition
SCADA
system based on a processor unit which receives information from IEDs, determines the
control requirements and sends commands to IEDs. A computer system that for example the
dispatchers use to monitor the power distribution throughout a service or control area
3.27
status
state condition of a component or system (st1/st2/.stn)
3.28
three phase data
measured value in a three phase electrical circuit with associated data attributes such as time
stamp, quality and calculation method
3.29
user/access management
management function used for setting up, modifying, deleting users (administratively),
assigning access rights (administratively) and monitoring access
3.30
wind power plant
complete system consisting of any number of technical subsystems referred to in the IEC
61400-25 series as wind power plant components, for example one or more wind turbines.
The main objective of a wind power plant is to generate electrical energy from the wind
3.31
wind power plant analogue information
continuous information concerning the actual condition or behaviour of a component or
system
– 12 – 61400-25-3 © IEC:2006(E)
NOTE Types are, for example, measured value, processed value, three phase value, setpoint, parameter.
3.32
wind power plant component
technical system employed in the operation of wind power plants, such as wind turbine,
meteorological, electrical and wind power plant management system
3.33
wind power plant management system
component of a wind power plant, which is responsible to ensure that the complete system
adapts itself to the static and dynamic conditions and requirements of the electrical power
connection (i.e., interoperation of the WTs with substation and other power network related
devices)
NOTE A wind power plant management system may include other functions (for example shadow control
functionality, noise or sound reduction, ice warning, lightning protection) not modelled in the IEC 61400-25 series.
3.34
wind turbine
main component of a wind power plant. It is responsible for generating energy and meets the
task of using the wind potential of a certain location that converts kinetic wind energy into
electric energy
4 Abbreviated terms
ACSI Abstract Communication Service Interface (defined for example in IEC 61850-7-2)
FCD Functionally Constrained Data
FCDA Functionally Constrained Data Attribute
IED Intelligent Electronic Device
IEM Information Exchange Model
LCB Log Control Block
LD Logical Device
LN Logical Node
LOG Log
LPHD Logical Node Physical Device
RCB Report Control Block
SCADA Supervisory Control and Data Acquisition
SCSM Specific Communication Service Mapping (defined for example in IEC 61850-8-1)
SG Setting Group
WPP Wind Power Plant
WT Wind Turbine
XML Extensible Mark-up Language
GUI Graphical User Interface
5 General
This part of IEC 61400-25 provides the information exchange models that can be applied by a
client and a server to access the content and structure of the wind power plant information
model defined in IEC 61400-25-2.
Clause 6 gives an overview of the information exchange models for operational functions and
management functions.
61400-25-3 © IEC:2006(E) – 13 –
Clause 7 introduces the information exchange models for operational functions: authorisation,
control, monitoring, and reporting and logging.
Clause 8 gives an overview of the information exchange models for management functions.
Clause 9 provides the details of the services for the following service model classes:
• Application association,
• Server class,
• Logical Device class (retrieve the self-description, etc.),
• Logical Node class (retrieve the self-description, etc.),
• Data class (get values, set values, retrieve the self-description, etc.),
• DataSet class (get values, set values, create data sets, retrieve the self-
description, etc.),
• Report Control Block class (get attributes, set attributes, report, etc.),
• Log Control Block and Log classes (get attributes, set attributes, retrieve log
entries, etc.),
• Control class (select, operate, etc.).
Annex A provides examples of the reporting and logging services required.
Annex B provides Relationship between ACSI Services and Functional Constraints.
Annex C provides Relationship between ACSI defined in IEC 61850-7-2 and IEC 61400-25-3.
6 Information exchange models overview
The information exchange models provide services for communication functions that are
grouped as follows:
• Operational functions,
• Management functions.
These two groups are introduced and described in more detail in the following clauses.
The mandatory services for each information exchange model are indicated in the
corresponding service tables in Clause 9.
An instance of the wind power plant information model of a wind power plant (logical device,
logical node, data, data attributes and control block objects) shall be accessed by instances
of the information exchange models listed in Table 1. The first two columns of the table
enumerate the functional groups and their information exchange models, which are summarily
described in the third column. The forth and fifth columns identify which data kinds and
transfer principles are applicable for each information exchange model. The last column
indicates the ACSI service models used for the corresponding information exchange models.

– 14 – 61400-25-3 © IEC:2006(E)
Table 1 – Information exchange models
Functional Information Short Information categories Transfer ACSI
group exchange description principles service
model models
Authentication and
Data transfer
restriction of
Authorisation on demand
access to
Short text messages ASSOCIATION
operational and Command
(see 7.2)
management
transfer
functions.
Command
Control of
Control Setpoints transfer CONTROL
operational
(see 7.3) Commands Set point
devices.
transfer
Measured Data
Processed data
(Average Values,
Min/Max)
Status
LOGICAL-
Alarms
DEVICE
Events
LOGICAL-
Monitoring of
Timer
NODE
current data and
Monitoring
Counter
change of data of
(see 7.4) DATA
Setpoints
operational
Periodic data
devices. Parameters
transfer (all
DATA-SET
data or only
Commands
BUFFERED-
data that has
Time Series Data (i.e.
changed since REPORT-
Alarm/Event Log,
last transfer) CONTROL
Command Log, Setpoint
Data transfer
Log)
UNBUFFERED-
on demand
(Analogue Values,
REPORT-
Binary Values) Event driven
CONTROL
data transfer
Histories (Logs)
(spontaneous)
LOG
Reports
Trigger controlled
Statistics
Reporting and LOG-
continuous
CONTROL
logging scanning and
Curves
recording of values
(see 7.4)
Trends
(see 9 for
and events.
Events
details of the
Short text messages ACSI services)
Monitoring, and
Diagnostics
Self-monitoring of reporting and logging
devices. information categories
(see 8.5)
apply
User and
Setting up users,
access
access rights and System specific
management
monitoring access.
(see 8.2)
Device
Setup
configuration System specific
(see 8.3)
management.
Time
Synchronization of
synchronisation
SCSM specific
device clocks.
(see 8.4)
The information exchange models shall be realised by the corresponding ACSI models and
associated services (as depicted in the last column in Table 1). The intent of the table is to
give an overview applying the commonly used terminology of the wind power plant domain.
Management (see Clause 8) Operational (see Clause 7 )

61400-25-3 © IEC:2006(E) – 15 –
7 Operational functions
7.1 General
The information exchange models for operational functions described in this Clause are as

follows
• Association and authorisation model,
• Control model,
• Monitoring, reporting and logging model.
Functional constraints of the ACSI services are specified in Annex B.
7.2 Association and authorisation model
The intention of the association and authorisation model is to provide a secure information
exchange via an association between a client and a server. The model provides client
authentication and controls the access to server functions. The conceptual mechanism is
shown in Figure 2.
secure
client server
association
local authorisation
association request
check requested
initiate remote
authorisation
authorisation
association opened (or denied) denied
?
Deny
wait for confirmation
granted
Grant
denied
ready to
?
receive requests
granted
end
operational information
operational information
process requests from
...
exchange (Get, Set,
client
Control, .)
no need to
communicate
close association
close association
close association
IEC  2186/06
Figure 2 – Association and authorisation model (conceptual)
The requirements to be fulfilled by an association between a client and as server are as
follows:
– authentication: determining the identity of the users/client,
– authorisation and access control: ensure that the entity has the proper access rights (a
minimum is to provide a user name and a password),
– integrity: messages and the computer infrastructure are protected against unauthorised
modification or destruction,
– confidentiality: objects of the Wind power plant information model are protected and only
disclosed to appropriate users/clients,
– non-repudiation: preventing a user/client involved in a data exchange from denying that it
participated in the exchange,
– 16 – 61400-25-3 © IEC:2006(E)
– prevention of denial of device: preventing a client/server from blocking access to
authorised users.
The real services of the authorisation model is provided by the specific mappings given in
IEC 61400-25-4. Based on the specific mapping selected, the actual level of security and the
specific services supported might be different.
7.3 Control model
The control model defines the Information Exchange models for commands and controlling of
a group of set points contained in an operational device. The conceptual mechanism is shown
in Figure 3.
client server
select
reserve ownership for
initiate control
exclusive control
ok
(optional)
(optional)
wait for operate
issue control
indication &
command operate/TimeActivatedOperate
process control
ok
command
IEC  2187/06
Figure 3 – Control model (conceptual)
The control model comprises the control of an operational device. Control functions might be
available to allow one client to have the exclusive right to control a device at a specific time.
The operate command “sets” the value of a controllable data (derived from controllable
common data classes).
NOTE The process to control the physical object is a local issue of the device that hosts the server. The IEC
61400-25 series defines just the external visible behaviour of the device. The control model as defined for the
server provides several parameters that determine the controlling process. The behaviour of the client is
complementary to the behaviour of the server.
The TimeActivatedOperate command is processed automatically by the server when the time
given by the service request is met.
7.4 Monitoring, reporting and logging model
The conceptual Information exchange models for monitoring, reporting and logging are shown
in Figure 4. The models comprise three independent information retrieval methods:
1) Values can be retrieved on demand by a client (upper part of the figure). This is
commonly known as Get or Read; the response will be transmitted immediately.
2) Values can be reported to the client, following a publisher/subscriber reporting model
(in the middle of the figure). The server is configured (locally or by means of a service)
to transmit values spontaneously or periodically. The client receives messages
(reports) whenever trigger conditions are met at the server. The publisher/subscriber
model may buffer events in case the communication link is down and transmit all
buffered events in sequence once the link is operating again, in case of a buffered
report. In the case of an unbuffered report, the delivery of events, in the case of a
communication link failure is not guaranteed.

...
61400-25-3 © IEC:2006(E) – 17 –
3) Values can be logged at the device. The logging model (at the bottom of the figure)
allows buffering and delivery of events in correct sequence. Logging values from
multiple sources of data (via configuration of Data Sets) may be logged and each
source can be configured independently of other sources. The client can query the log
for entries between two timestamps or for all entries after a certain entry.
The reporting and logging models include:
a) a Data Set class (DS), for referencing groups of data to be logged or reported,
b) Control Block class (report control block class or log control block class), for controlling
the dynamic behaviour of the information logging or reporting, and
c) a Log class, for definition of log storage.
client server
request values,
send values
values on demand
receive values,
on demand
process values locally
subscribe to receive values
establish and
initiate subscription
enable subscription
monitor values for
wait for values,
change (periodic),
receive values,
produce events and
values on change or event
process and/or
send values
display values locally
periodic values send values to
subscriber periodically
RemoveSubscribtion
disable subscription disable subscription
query
value
values of a time-series
query time-series values
of data values
value
LOG
values
process values locally value
time
IEC  2188/06
Figure 4 – Monitoring, reporting and logging model (conceptual)
The retrieval methods have the characteristics given in Table 2.

– 18 – 61400-25-3 © IEC:2006(E)
Table 2 – Comparison of the information retrieval methods
Retrieval method Time-critical Can lose Multiple Last Typical client
information changes (of clients to receive change of (but not
exchange sequence) information data stored exclusively)
by
Data on demand NO YES YES - Browser
Subscription YES YES/NO YES Server Real-time GUI
Unbuffered YES YES YES - Real-time GUI
Reporting
reporting
Buffered YES NO YES Server Data concentrator
reporting*
Logging NO NO YES Client Plant operation,
engineering
stations
Each of the retrieval methods has specific characteristics. There is no single method that
meets all application requirements. During system design, the designer shall analyse the
requirements and to check them against the (implemented) methods provided by a device
compliant with the IEC 61400-25 series.
8 Management functions
8.1 General
The management function models described in this Clause are used to set-up or evolve
(maintain) a system. The system configuration and maintenance functions include the setting
and changing of configuration data and the retrieval of configuration information from the
system. The management function models described are as follows
• User management/access security model,
• Setup model,
• Time synchronisation model,
• Diagnostic (self monitoring) model.
Functional constraints of the ACSI services are specified in Annex B.
8.2 User management/access security model
Apart from the service requirements given in 7.2 these functions are an implementation-
specific issue.
8.3 Setup model
Apart from the service requirements given in 7.2 these functions are an implementation-
specific issue.
8.4 Time synchronisation model
The synchronisation of the various clocks in a system is a matter of the specific mapping
selected and specified in IEC 61400-25-4.
8.5 Diagnostic (self-monitoring) model
The diagnostic or self-monitoring functions, are intended for detection of the system status for
example if a device is fully operational, partially operational, or not operational. The diagnosis
information is defined in the logical node LPHD defined in IEC 61400-25-2.

61400-25-3 © IEC:2006(E) – 19 –
9 The ACSI for wind power plant information models
9.1 General
The information exchanges models specified in Clause 7 and 8 create an overview of the
models required to be compliant with the IEC 61400-25 series. Clause 9 contains the detailed
description of all service required.
The basic information exchange models are depicted in Figure 5, illustrating the various
components of the ACSI services. This figure is used to provide a narrative description of how
a typical device interacts with the outside world using these services.

Server
Logical device
Get/Set
nameplate, health Logical node
Data
Logical Node
Get/Set
Control
Data values
Data
Data
Get/Set
Data
Data
Set
Subscribe
set
Report control block
values on
values on
Recporhant ge, event,
change, event,
(values on change,
periodic
periodic
event, periodic)
Log control block
Query
Log
Authorisation Time synchronisation
bidirectional information exchange
reference
unidirectional information exchange

IEC  2188/06
Figure 5 – Conceptual information exchange model for a wind power plant
The specification in this Clause provides a high level definition of services. The normative
definition of the details of the ACSI models and services are defined in IEC 61850-7-2.
9.2 Services of Association and authorisation
The application association model consists of provisions on how the communication between
the various types of devices is achieved. The model comprises:
• Class definitions of associations, a
...