IEC TS 61850-2:2003

TECHNICAL IEC
SPECIFICATION
TS 61850-2
First edition
2003-08
Communication networks and systems
in substations –
Part 2:
Glossary
Reference number
IEC/TS 61850-2:2003(E)
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TECHNICAL IEC
SPECIFICATION
TS 61850-2
First edition
2003-08
Communication networks and systems
in substations –
Part 2:
Glossary
 IEC 2003  Copyright - all rights reserved
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– 2 – TS 61850-2  IEC:2003(E)

CONTENTS
FOREWORD . 3

1 Scope . 5

2 Terms and definitions. 5

3 Abbreviations .28

Bibliography .40

TS 61850-2  IEC:2003(E) – 3 –

INTERNATIONAL ELECTROTECHNICAL COMMISSION

___________
COMMUNICATION NETWORKS AND SYSTEMS

IN SUBSTATIONS –
Part 2: Glossary
FOREWORD
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all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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The main task of IEC technical committees is to prepare International Standards. In

exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 61850-2, which is a technical specification, has been prepared by IEC technical committee
57: Power system control and associated communications.

– 4 – TS 61850-2  IEC:2003(E)

The text of this technical specification is based on the following documents:

Enquiry draft Report on voting

57/615/DTS 57/645/RVC
Full information on the voting for the approval of this technical specification can be found in the

report on voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

IEC 61850 consists of the following parts, under the general title Communication networks and
systems in substations.
Part 1: Introduction and overview
Part 2: Glossary
Part 3: General requirements
Part 4: System and project management
Part 5: Communication requirements for functions and device models
Part 6: Configuration description language for communication in electrical substations

related to IEDs
Part 7-1: Basic communication structure for substation and feeder equipment – Principles and
models
Part 7-2: Basic communication structure for substation and feeder equipment – Abstract
communication service interface (ACSI)
Part 7-3: Basic communication structure for substation and feeder equipment – Common data
classes
Part 7-4: Basic communication structure for substation and feeder equipment – Compatible
logical node classes and data classes
Part 8-1: Specific communication service mapping (SCSM) – Mappings to MMS (ISO/IEC
9506-1 and ISO/IEC 9506-2) over ISO/IEC 8802-3
Part 9-1: Specific communication service mapping (SCSM) – Sampled values over serial
unidirectional multidrop point to point link
Part 9-2: Specific communication service mapping (SCSM) – Sampled values over
ISO/IEC 8802-3
Part 10: Conformance testing
The committee has decided that the contents of this publication will remain unchanged until
2005. At this date, the publication will be either
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
___________
Under consideration.
TS 61850-2  IEC:2003(E) – 5 –

COMMUNICATION NETWORKS AND SYSTEMS

IN SUBSTATIONS -
Part 2: Glossary
1 Scope
This part of the IEC 61850 series applies to Substation Automation Systems (SAS). It defines
the communication between intelligent electronic devices (IEDs) in the substation and the
related system requirements.
This part of the IEC 61850 series contains the glossary of specific terminology and definitions
used in the context of Substation Automation Systems within the various parts of the standard.
2 Terms and definitions
The following terms and definitions apply to all parts of the IEC 61850 series .
2.1
abstract communication service interface
virtual interface to an IED providing abstract information modelling methods for logical devices,
logical nodes, data, and data attributes, and communication services for example connection,
variable access, unsolicited data transfer, device control and file transfer services, independent
of the actual communication stack and profiles used
[IEC 61850-1]
2.2
access point
communication access point to an IED. This may be a serial port, an Ethernet connection, or a
client or server address dependent on the stack being used. Each access point of an IED to a
communication bus is uniquely identified. Each server has only one, logical, access point
[IEC 61850-6]
2.3
application layer
layer 7 in the OSI reference model for Open Systems Interconnection comprising the interface
between the OSI environment and the IED’s or user’s application
[ISO/IEC 7498-1]
2.4
association
conveyance path established between a client and a server for the exchange of messages
[IEC 61850-7-1]
___________
References to other standards given below certain definitions indicate that the term is either described or used in
the cited standard. All references are listed in the bibliography.

– 6 – TS 61850-2  IEC:2003(E)

2.5
attribute
named element of data and of a specific type

[IEC 61850-8-1]
2.6
bay
a substation consists of closely connected sub parts with some common functionality.

Examples are the switchgear between an incoming or outgoing line, and the busbar, the bus
coupler with its circuit breaker and related isolators and earthing switches, the transformer with
its related switchgear between the two busbars representing the two voltage levels. The bay

concept may be applied to 1½ breaker and ring bus substation arrangements by grouping the
primary circuit breakers and associated equipment into a virtual bay. These bays comprise a
power system subset to be protected, for example a transformer or a line end, and the control
of its switchgear that has some common restrictions such as mutual interlocking or well-
defined operation sequences. The identification of such subparts is important for maintenance
purposes (what parts may be switched off at the same time with minimum impact on the rest of
the substation) or for extension plans (what has to be added if a new line is to be linked in).
These subparts are called ‘bays’ and may be managed by devices with the generic name ’bay
controller’ and have protection systems called ‘bay protection’.
The concept of a bay is not commonly used in North America. The bay level represents an
additional control level below the overall station level
[IEC 61850-1]
2.7
bay level functions
functions that use mainly the data of one bay and act mainly on the primary equipment of that
bay. Bay level functions communicate via logical interface 3 within the bay level and via the
logical interfaces 4 and 5 to the process level, i.e. with any kind of remote input/output or with
intelligent sensors and actuators
EXAMPLES Feeder or transformer, protection, control and interlocking.
[IEC 61850-5]
2.8
broadcast
message placed onto a communication network intended to be read and acted on, as
appropriate, by any IED. A broadcast message will typically contain the sender’s address and a
global recipient address
EXAMPLE Time synchronising.
[IEC 61850-7-2]
2.9
bus
communication system connection between IEDs with communication facilities
[IEC 61850-1]
2.10
class
description of a set of objects that share the same attributes, services, relationships and
semantics
[IEC 61850-7-1]
TS 61850-2  IEC:2003(E) – 7 –

2.11
client
entity that requests a service from a server, or which receives unsolicited data from a server

[IEC 61850-7-1]
2.12
communication connection
connection which utilises the communication mapping function of one or more resources for

the conveyance of information
[IEC 61850-10]
2.13
communication stack
multi-layer stack. In the 7 layer OSI reference model for Open Systems Interconnection, each
layer performs specific functions related to Open Systems Interconnection communication
[ISO/IEC 7498-1]
2.14
configuration (of a system or device)
step in system design for example selecting functional units, assigning their locations and
defining their interconnections
[IEV 351]
2.15
configuration list
overview of all compatible hardware and software versions of components and IEDs, including
the software versions of relevant supporting tools, operating together in a SAS product family.
Additionally, the configuration list details the supported transmission protocols for com-
munication with IEDs of other manufacturers
[IEC 61850-4]
2.16
conformance test
check of data flow on communication channels in accordance with the standard conditions
concerning access organization, formats and bit sequences, time synchronization, timing,
signal form and level and reaction to errors. The conformance test can be carried out and
certified to the standard or to specifically described parts of the standard. The conformance
test should be carried out by an ISO 9001 certified organisation or system integrator
[IEC 61850-4]
2.17
connection
association established between functional units for conveying information. A connection is
established between two IEDs prior to any data exchange. A connection may be of short
duration or long term
[IEC 61850-3]
2.18
connectivity node
an identifiable, named, common connection point between terminals of primary devices whose
only function is to connect them electrically with minimum resistance; for example a bus bar as
a connectivity node connects bus bar disconnectors. The connection to a device is done at a
device terminal. A connectivity node can connect an arbitrary number of terminals (devices)
[IEC 61850-6]
– 8 – TS 61850-2  IEC:2003(E)

2.19
Cyclic Redundancy Check
CRC
this is calculated and included in each frame transmitted by the sending device, the receiving

device recalculates the CRC for that frame, as received, as a check for any transit damage in

that frame
[IEC 61850-9-1]
2.20
data
meaningful, structured, information of applications, located in an IED, which can be read or

written
[IEC 61850-8-1]
2.21
data attribute
defines the name (semantic), format, range of possible values, and representation of values
while being communicated
[IEC 61850-7-2]
2.22
data class
class that aggregates data classes or data attributes. Specific data classes carry the semantic
within a logical node
[IEC 61850-7-2]
2.23
data link layer
layer 2 of the OSI reference model for Open Systems Interconnection, responsible for the
transmission of data over a physical medium. After establishment of a link, layer 2 performs
data rate control, error detection, contention/collision detection, quality of service monitoring
and error recovery
[ISO/IEC 7498-1]
2.24
data object
part of a logical node object representing specific information for example status or
measurement. From an object-oriented point of view, a data object is an instance of a data

class
[IEC 61850-1]
2.25
data set class
named list of ordered references to one or more Functionally Constrained Data (FCD) or
Functionally Constrained Data Attributes (FCDA). Used to group commonly used data objects
for easy retrieval
[IEC 61850-7-2]
TS 61850-2  IEC:2003(E) – 9 –

2.26
device
element or assembly of elements performing a required function

NOTE A device may form part of a larger device.

[IEV 151]
mechanism or piece of equipment designed to serve a purpose or perform a function for

example, circuit breaker, relay or substation computer

[IEEE Std. 100–1996, IEEE dictionary of electrical and electronic terms]

in the context of a switchyard, a device is a physical plant item for example transformer or
circuit breaker; in the context of substation automation a device is an IED
[IEC 61850-1]
2.27
diameter
refers to a 1½ breaker arrangement and comprises the complete switchgear between the two
busbars, i.e. the 2 lines and the 3 circuit breakers with all related isolators, earthing switches,
CT's and VT's. It has some common functionality and relationship both for operation,
maintenance and extensions
[IEC 61850-5]
2.28
distributed function
when two, or more, logical nodes, that are located in different physical devices, together
perform a function. Since all functions communicate in some way, the definition of a local or
distributed function is not unique but depends on the definition of the functional steps to be
performed until the function is completed. In the case of loss of one LN or one included
communication link, the function may be blocked completely or show a graceful degradation,
as applicable
[IEC 61850-5]
2.29
distribution
with reference to a power system, distribution refers to that part of the power system operating
at voltages typically up to 69 kV
[IEC 61850-4]
2.30
electronic current transducer
transducer in the primary plant measuring system current and providing low level analogue
and/or digital data output(s)
2.31
electronic voltage transducer
transducer in the primary plant measuring system voltage(s) and providing low level analogue
and/or digital output(s)
2.32
engineering
first phase of a project i.e. detail design

– 10 – TS 61850-2  IEC:2003(E)

2.33
engineering tools
these support the creation and documentation of the conditions for adapting the SAS to the

specific substation and customer requirements. The engineering tools are divided into project

management, parameterization and documentation tools

[IEC 61850-4]
2.34
equipment
entity that performs an energy transport function for example transformer, circuit breaker, line.
It may be stand alone or interfaced to an automation system via an integral device or

associated external device
[IEC 61850-7-2]
2.35
expandability
criterion for the fast and efficient extension of an SAS (both hardware and software) by use of
the engineering tools
[IEC 61850-4]
2.36
factory acceptance test
customer agreed functional tests of the specifically manufactured SAS installation or its parts,
using the parameter set for the planned application. This test should be carried out in the
factory of the system integrator by use of process simulating test equipment
[IEC 61850-4]
2.37
flexibility
criterion for the fast and efficient implementation of functional changes, including hardware
adaptation, in an SAS by use of the engineering tools
[IEC 61850-4]
2.38
freeze
associated typically with measurands and counters. To freeze a value is to lock and hold the
value at that instant
2.39
function(s)
task(s) performed by the substation automation system i.e. by application functions. Generally,
functions exchange data with other functions. Details are dependant on the functions involved.
Functions are performed by IEDs (physical devices). A function may be split into parts residing
in different IEDs but communicating with each other (distributed function) and with parts of
other functions. These communicating parts are called logical nodes.
In the context of this standard, the decomposition of functions or their granularity is ruled by
the communication behaviour only. Therefore, all functions considered consist of logical nodes
that exchange data. Functions without an explicit reference to logical nodes mean only that in
the actual context, the logical node modelling of these functions is of no importance to the
standard
[IEC 61850-1]
TS 61850-2  IEC:2003(E) – 11 –

2.40
functional constraint
property of a data-attribute that indicates the services for example read value, write value,

substitute value, etc. that may be applied to that data attribute

[IEC 61850-7-2]
2.41
functionally constrained data
reference to an ordered collection of data having the same functional constraint for example all
MX (measurands)
[IEC 61850-7-2]
2.42
functionally constrained data attribute
reference to a single data-attribute, of data, to which a specific functional constraint applies
[IEC 61850-7-2]
2.43
gateway
network interconnection device that supports the full stack of the relevant protocol which it can
convert to a non 7 layer protocol for asynchronous transmission over wide area networks
[IEC 61850-7-1]
2.44
generic object oriented substation event
on the occurrence of any change of state, an IED will multicast a high speed, binary object,
Generic Object Oriented Substation Event (GOOSE) report by exception, typically containing
the double command state of each of its status inputs, starters, output elements and relays,
actual and virtual.
This report is re-issued sequentially, typically after the first report, again at intervals of 2, 4,
8…60000 ms. (The first repetition delay value is an open value it may be either shorter or
longer).
A GOOSE report enables high speed trip signals to be issued with a high probability of delivery
[IEC 61850-5]
2.45
generic substation event model
defines two classes of multicast/broadcast data i.e. GOOSE and GSSE, for the fast transfer of
input and output data values between IEDs
2.46
generic substation state event
similar to GOOSE but restricts the contained-data to data values of a number of double-
command (bit pairs) status values, for example open, closed, in transition, or invalid states
[IEC 61850-7-2]
– 12 – TS 61850-2  IEC:2003(E)

2.47
hold point
point, defined in the appropriate document, beyond which an activity must not proceed without

the written approval of the initiator of the conformance test. The test facility must provide a

written notice to the initiator at an agreed time prior to the hold point. The initiator, or his

representative, is obligated to verify the hold point and approve the resumption of the testing

[IEC 61850-10]
2.48
hub
active network component. Each port of a hub links individual media segments together to
create a larger network that operates as a single LAN. Collisions in the network are possible
[IEC 61850-3]
2.49
Human Machine Interface
HMI
display screen, either part of an IED or as a stand-alone device, presenting relevant data in a
logical format, with which the user interacts. An HMI will typically present windows, icons,
menus, pointers, and may include a keypad to enable user access and interaction
2.50
IED-parameter set
all the parameter values needed for the definition of the behaviour of the IED and its adaptation
to the substation conditions. Where the IED has to operate autonomously, the IED-parameter-
set can be generated without system parameters using an IED-specific parameterisation tool.
Where the IED is a part of the SAS, the IED-parameter set may include system parameters,
which must be co-ordinated by a general parameterisation tool at the SAS level
[IEC 61850-4]
2.51
implementation
development phase in which the hardware and software of a system become operational
[IEC 61850-7-1]
2.52
information
knowledge concerning objects, such as facts, events, things, processes, or ideas, including

concepts, that within a certain context has a particular meaning
[IEV 101-12-01]
2.53
information model
knowledge concerning substation functions (devices) made visible and accessible through the
means of the IEC 61850 series. The model describes in an abstract way a simplified
representation of a real function or device
[IEC 61850-7-1]
2.54
initiator of conformance test
party initiating a conformance test that is to be performed by a test facility
[IEC 61850-10]
TS 61850-2  IEC:2003(E) – 13 –

2.55
inspection
activity such as measuring, examining, testing or gauging of one or more characteristics of an

entity and comparing the results with specified requirements in order to establish whether

conformity is achieved for each characteristic

[IEC 61850-10]
2.56
instance
entity that has an unique identity, with the attributes of a defined class, to which a set of
services can be applied and which has a state that stores the effects of the services. ‘Instance’

is synonymous with ‘object’
[IEC 61850-7-1]
2.57
instance name
identifier associated with and designating an instance
[IEC 61850-7-1]
2.58
instantiation
creation of an instance of a specified class
[IEC 61850-5]
2.59
Intelligent Electronic Device
IED
any device incorporating one or more processors, with the capability to receive or send,
data/control from, or to, an external source, for example electronic multi-function meters,
digital relays, controllers.
Device capable of executing the behaviour of one or more, specified logical nodes in a
particular context and delimited by its interfaces
[IEC 61850-1]
2.60
interchangeability
ability to replace a device supplied by one manufacturer with a device supplied by another

manufacturer, without making changes to the other elements in the system
[IEC 61850-1]
2.61
interface
shared boundary between two functional units, defined by functional characteristics for
example common physical interconnection characteristics, signal characteristics or other
characteristics as appropriate, and the provision of a declared collection of services
[IEC 61850-5]
– 14 – TS 61850-2  IEC:2003(E)

2.62
interface related station level functions
functions representing the interface of the SAS local station-operator HMI to a remote control

centre Tele-Control Interface (TCI) or to the remote engineering Tele-Monitoring Interface

(TMI) for monitoring and maintenance purposes. These functions communicate via the logical

interfaces 1 and 6 with the bay level and via logical interface 7 to technical services and via the

remote control interface to the outside world. Logically, there is no difference if the HMI is local

or remote. In the context of the substation, there exists at least a virtual interface for the SAS

at the boundary of the substation. The same is true for both the TCI and TMI. These virtual

interfaces may be realised in some implementations such as proxy servers

[IEC 61850-5]
2.63
internet protocol
TCP/IP standard internet protocol defines the datagram that provides the basis of
connectionless packet delivery. It includes control and error message protocol providing the
equivalent functions to network services, layer 3, of the OSI reference model for Open Systems
Interconnection
[IEC 61850-3]
2.64
interoperability
ability of two or more IEDs from the same vendor, or different vendors, to exchange
information and use that information for correct execution of specified functions
[IEC 61850-1]
2.65
life cycle
of an IED or system, covers all phases from the feasibility/concept phase through to the final
decommissioning phase
[IEC 61850-10]
2.66
link layer
see data link layer
[IEC 61850-7-1]
2.67
local area network
communications network which typically covers the area within a building or small industrial
complex. In the context of this standard, the area within the substation
[IEC 61850-9-1]
2.68
log
record (journal), of chronologically ordered data for example events with time tags and
annotations
[IEC 61850-5]
TS 61850-2  IEC:2003(E) – 15 –

2.69
logical connection
communication link between logical nodes

[IEC 61850-5]
2.70
logical device class
virtual device that exists to enable aggregation of related logical nodes and data set(s) for

communication purposes. In addition, logical devices contain convenient lists of frequently

accessed, or referred to, information for example data sets

[IEC 61850-7-2]
2.71
logical device object
instance of the class of logical device
[IEC 61850-7-2]
2.72
logical node
smallest part of a function that exchanges data. A logical node is an object defined by its data
and methods
[IEC 61850-1]
2.73
logical node class
aggregation of data, data sets, report controls, log controls, logs, GOOSE and GSSE controls
and sampled measured values. Logical node classes represent typical functions of the
substation system. IEC 61850-7-4 defines a list of compatible logical node classes for
protection functions, supervisory control, metering, switchgear, power transformers, etc.
[IEC 61850-7-2]
2.74
logical node data
information contained within a logical node. The term encompasses ACSI data, control blocks,
etc.
[IEC 61850-8-1]
2.75
logical node object
instance of a logical node class
[IEC 61850-7-2]
2.76
logical system
union (via its logical nodes) of all communicating application functions performing some overall
task for example ‘management of a substation’. The boundary of a system is given by its
logical or physical interfaces: examples are industrial systems, management systems,
information systems, etc.
[IEC 61850-5]
– 16 – TS 61850-2  IEC:2003(E)

2.77
manufacturer
producer of IEDs and/or supporting tools. A manufacturer may be able to deliver an SAS solely

by use of his own IEDs and supporting tools (SAS product family)

[IEC 61850-4]
2.78
mapping
set of values having a defined correlation with the quantities, or values, of another set

[IEC 61850-1]
2.79
merging unit
physical unit performing the time coherent combination of the current and/or voltage data
coming from the secondary converters. The merging unit can be part of one of the transducers
in the field or may be a separate unit for example in the control room
[IEC 60044-8]
interface unit that accepts multiple analogue CT/VT and binary inputs and produces multiple
time synchronised serial unidirectional multi-drop digital point to point outputs to provide data
communication via the logical interfaces 4 and 5
[IEC 61850-9-1]
2.80
message
inherent attribute of a communication between IEDs, functions or instances, that conveys
service specific data or commands, on receipt of which it is expected that action will be taken
[IEC 61850-3]
2.81
model
representation of some aspects of reality. The purpose of creating a model is to help
understand, describe, or predict how things work in the real world by exploring a simplified
representation of a particular entity or phenomenon
[IEC 61850-7-1]
2.82
model implementation conformance statement
details the standard data object models supported by the system or device
[IEC 61850-10]
2.83
multicast
uni-directional, connectionless communication between a server and a selected set of clients
[IEC 61850-6]
2.84
name plate
name for the set of data typically found on an item of a plant for example a power transformer,
or an IED for example a protection relay, that uniquely describes that device’s identity and
attributes
[IEC 61850-7-2]
TS 61850-2  IEC:2003(E) – 17 –

2.85
negative test
test to verify the correct response of a device or a system to the following standards:

• IEC 61850 conformant information and services which are not implemented in the device or

system under test.
• Non IEC 61850 conformant information and services sent to the device or system under

test.
[IEC 61850-10]
2.86
network
layer 3 of the OSI reference model for Open Systems Interconnection, provides functional and
procedural means of connectionless or connection-mode transmission, also independence
from routing and communications relaying considerations, enabling the transparent transfer of
data between transport entities
[ISO/IEC 7498-1]
2.87
object
instance
descriptor of an instance of a class of entity that is uniquely identifiable within the SAS domain,
with defined boundaries and identity which encapsulates states and behaviour. States are
represented by attributes, behaviour by services and state machines
[IEC 61850-1]
2.88
object attribute
field or a category or value of data that, together with other attributes, specify the services or
data values related to the function and performance of an object
[IEC 61850-6]
2.89
object name
unique full reference identifier of a specific data object that is unique within the SAS domain, or
within a specific domain.
It is constructed by concatenation, using dot ‘.’ deliminators, to as many hierarchical levels as
required, for example
‘BasicDataClass.StructuredComponent.X.X.X.etc’
[IEC 61850-6]
2.90
open protocol
protocol whose stack is either standardised or publicly available
[IEC 61850-1]
2.91
parameters
variables which define the behaviour of functions of the SAS and its IEDs within a given range
of values
[IEC 61850-4]
– 18 – TS 61850-2  IEC:2003(E)

2.92
physical connection
communication link between physical devices

[IEC 61850-5]
2.93
physical device
equivalent to an intelligent electronic device as used in the context of this standard

[IEC 61850-1]
2.94
physical layer
layer 1 of the OSI reference model for Open Systems Interconnection provides the mechanical,
electrical, functional and procedural means to activate, maintain and de-activate physical
connections for bit transmission between data-link entities. Physical layer entities are
interconnected by means of a physical medium
[ISO/IEC 7498-1]
2.95
physical node
point of connection on a physical device to a communication network. A physical node is a
multi-functional unit providing both the communication server and the mapping to the real
substation IED
[IEC 61850-1]
2.96
physical system
is composed of the IEDs and the interconnecting physical communication network (commonly
fibre-optics). The boundary of a system is given by its logical or physical interfaces: examples
are industrial systems, management systems, information systems, etc.
[IEC 61850-5]
2.97
piece of information for communication
exchanged data are called Piece of Information for COMmunication (PICOM) as adopted from
the approach of the CIGRE working group 34.03. PICOM is a description of an information
transfer on a given logical connection with given communication attributes between two logical
nodes. It also contains the information to be transmitted and required attributes for example

performance. It does not represent the actual structure or format of the data that is transmitted
over the communication network
[IEC 61850-1]
2.98
point to point
one to one communication link between two nodes, used only for communication between
those two nodes
[IEC 61850-9-1]
TS 61850-2  IEC:2003(E) – 19 –

2.99
positive test
test to ensure the correct implementation of the system capabilities as defined by the supplier.

A positive test has a described and defined response

[IEC 61850-10]
2.100
presentation layer
layer 6 of the OSI reference model for Open Systems Interconnection, provides an interface

between the concrete local syntax used by the Application layer and the negotiated abstract

and transfer syntaxes to be used for the transfer of data during a communication session
between the two communicating application entities
[ISO/IEC 7498-1]
2.101
process level functions
all functions interfacing to the process, i.e. binary and analogue input/output functions for
example data acquisition (including sampling) and the issuing of commands. These functions
communicate via the logical interfaces 4 and 5 to the bay level
[IEC 61850-5]
2.102
process related station level functions
use data from more than one bay, or from the whole substation and act on the primary
equipment of more than one bay, or on the primary equipment of the whole substation.
Examples of such functions are: station wide interlocking, automatic sequencers, and busbar
protection. These functions communicate mainly via the logical interface 8
[IEC 61850-5]
2.103
profile(s)
defined format(s) used by a particular protocol to transmit data objects or commands, etc.
[IEC 61850-7-1]
2.104
protocol
set of rules that determines the behaviour of functional units in achieving communication

[ISO/IEC 2382-9; IEC 61850-1]
2.105
protocol converter
intelligent electronic device connected between two communication networks, that is capable of
translating messages received in one protocol on one network to a second protocol for re-
transmission on the other network and vice versa
2.106
protocol data unit
encoded message containing the service parameters

– 20 – TS 61850-2  IEC:2003(E)

2.107
protocol implementation conformance statement
summary of the capabilities of the system to be tested

[ISO/IEC 8823-2:1994]
Protocol Implementation Conformance Statements (PICS) contain information regarding the

ACSI. This information could typically be optional parts, specific restrictions, or add-ons

[IEC 61850-7-2]
2.108
protocol implementation extra information for testing
document (PIXIT) containing system specific information regarding the capabilities of the
system to be tested which are outside the scope of the IEC 61850 series. Provides information
regarding the physical set-up that is not part of the ACSI. This could be information regarding
the hardware, socket, and other information.
The PIXIT shall not be subjected to standardisation
[IEC 61850-10]
2.109
redundant
redundancy
existence of more than one means for performing a required function in an item
[IEV 191]
refers to spare or duplicate functionality that allows a system to continue to operate without
degradation of performance in the event of single failure for example a blown fuse
2.110
remote terminal unit
typically an outstation in a SCADA system, a Remote Terminal Unit (RTU) may act as an
interface between the communication network and the substation equipment. The function of
an RTU may reside in one IED or may be distributed
[IEC 61850-4]
2.111
report
agreed, or client defined, set of data compiled by an IED for transmission to a client at regular,

or specified time intervals, or on demand. A report may also be generated as a result of one or
more, trigger conditions that may be either pre-set or pre-defined by the client
[IEC 61850-6]
2.112
review
systematic examination, as defined in the appropriate document, of the quality document(s) for
an activity. The test facility must provide the documentation to be reviewed to the initiator of the
conformance test at an agreed time prior to the associated hold or witness point. How the
review is conducted is subject to agreement
[IEC 61850-10]
TS 61850-2  IEC:2003(E) – 21 –

2.113
SAS installation
concrete instance of an SAS consisting of multiple, interoperable, IEDs from one, or more,

manufacturers
[IEC 61850-4]
2.114
SAS parameter set
all the parameters needed for the definition of the behaviour of the overall SAS and its
adaptation to the substation conditions. The SAS parameter set includes the IED parameter
sets of all participating IEDs

[IEC 61850-4]
2.115
SAS product family
range of different IEDs from one manufacturer, with various functionalities and with the ability
to perform substation automation system functions. The IEDs of a product family are unified in
relation to the design, the operational handling, the mounting and wiring requirements and they
use common or co-ordinated, supporting tools
[IEC 61850-4]
2.116
scalability
criterion for a cost effective SAS taking into account the various functionalities, various IEDs,
substation sizes and substation voltage ranges
[IEC 61850-4]
2.117
selector
defines the references to a class instance for accessing the instance values
[IEC 61850-7-2]
2.118
self-description
device contains information on its configuration. The representation of this information has to
be standardised and has to be accessible via communication (in the context of this standard
series)
[IEC 61850-1]
2.119
server
on a communication network, a functional node that provides data to, or that allows access to
its resources by, other functional nodes. A server may also be a logical subdivision, which has
independent control of its operation, within the software algorithm (and/or possibly hardware)
structure
[IEC 61850-6]
2.120
server class
external visible behaviour of an IED or application process
[IEC 61850-7-2]
– 22 – TS 61850-2  IEC:2003(E)

2.121
service
functional capability of a resource which can be modelled by a sequence of service primitives

2.122
service access point
represents a logical construct through which a peer selects a communication protocol or

access to an application. The selection of the entire seven layers of a service access point

represents a communication profile

[IEC 61850-8-1]
2.123
service primitive
abstract, implementation independent, representation of an interaction between the service
user and the service provider
2.124
session
layer 5 of the OSI reference model for Open Systems Interconnection, manages the
establishment and release, of session connections, also the synchronisation of data exchange
between presentation entities
[ISO/IEC 7498]
2.125
SF
Sulphur HexaFluoride gas, used as an insulating medium in gas insulated circuit breakers and
associated plant
[IEC 61850-3]
2.126
site acceptance test
verification of each data and control point and the correct functionality inside the SAS and
between the SAS and its operating environment on the whole installed plant using the final
parameter set. The site acceptance test is the pre-condition for the SAS being accepted and
put into service
[IEC 61850-4]
2.127
specific communication service mapping
standardised procedure which provides the concrete mapping of ACSI services and objects
onto a particular protocol stack/communication profile.
To reach inte
...