IEC 62744:2014

IEC 62744 ®
Edition 1.0 2014-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
HORIZONTAL STANDARD
NORME HORIZONTALE
Representation of states of objects by graphical symbols

Représentation d'états d'objets par des symboles graphiques

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IEC 62744 ®
Edition 1.0 2014-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
HORIZONTAL STANDARD
NORME HORIZONTALE
Representation of states of objects by graphical symbols

Représentation d'états d'objets par des symboles graphiques

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
V
CODE PRIX
ICS 01.080.20 ISBN 978-2-8322-1935-5

– 2 – IEC 62744:2014 © IEC 2014
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references. 7
3 Terms, definitions and abbreviations . 8
3.1 Terms and definitions . 8
3.2 Abbreviations . 12
4 General . 12
5 Reasons for dynamic representation of objects . 13
5.1 General . 13
5.2 Change of state of an object in the supervised process . 13
5.3 Operators command/action . 14
5.4 Time controlled activities . 15
5.5 Sporadic change . 15
6 Area of application . 16
6.1 General . 16
6.2 SCADA user interface . 16
6.3 Process control user interface . 16
6.4 Engineering and configuration tool interface . 16
6.5 Different operator displays of product with interactive functions . 16
6.6 Graphical symbols related to safety signal words such as danger, warning
and caution . 17
6.6.1 Graphical symbols related to safety . 17
6.6.2 Symbols in alarm and signalling displays . 18
6.7 Representation of actuators . 18
6.7.1 General . 18
6.7.2 Recommended location of information associated with graphical
symbols . 18
6.8 Instructions for use in electronic form . 20
7 Types of presentation – Rules and examples . 20
7.1 General . 20
7.2 Change of shape . 21
7.2.1 General . 21
7.2.2 Usage of symbols . 21
7.3 Change of colours . 21
7.3.1 General . 21
7.3.2 Use of background colours . 22
7.3.3 Colour contrast . 22
7.3.4 Operational states and associated recommended colours . 22
7.3.5 Flashing . 22
7.4 Change size . 23
7.5 Acoustic codes . 23
7.6 Actuators as parts of a pictorial presentation on a video display unit. 23
7.7 Add-in or change letters/text . 23
7.8 Combination of presentation types on the same graphical symbol . 24
8 Consideration of regional or national legislation . 28

Annex A (informative) Example of presentation of a graphical symbol in different
forms for use on equipment . 29
Bibliography . 30

Figure 1 – Example of changing the operational state from OFF to ON . 15
Figure 2 – Recommended location of information associated with graphical symbols . 19
Figure 3 – Examples of graphical symbols including related information . 20

Table 1 – Generic operational states used during operation of an object (informative /
exemplary) . 13
Table 2 – General principles for meaning of basic shapes . 17
Table 3 – Meaning of indication codes with respect to the operational states . 25
Table A.1 – Example of presentation of the graphical symbol ISO 7000-0034
representing different operational temperature states . 29

– 4 – IEC 62744:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
REPRESENTATION OF STATES OF
OBJECTS BY GRAPHICAL SYMBOLS
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62744 has been prepared by IEC technical committee 3:
Information structures, documentation and graphical symbols.
It has the status of a horizontal standard in accordance with IEC Guide 108.
The text of this standard is based on the following documents:
FDIS Report on voting
3/1194A/FDIS 3/1205/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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.
– 6 – IEC 62744:2014 © IEC 2014
INTRODUCTION
This international standard deals with the representation of operational states of objects by
standardized graphical symbols. The graphical symbols presented in standards like
IEC 60417, IEC 60617 and ISO 14617 are actually presented in a static form. This standard
establishes rules and recommendations for how objects being represented by graphical
symbols can be presented with a dynamic behaviour indicating the operational states of
objects occurring in practice. This standard provides guidance for developers and designers
of graphical symbols, for example in IEC 60617, ISO 14617, IEC 60417 or any other pictorial
representation of an object if being requested to consider additional forms for the presentation
of operational states.
This standard also provides information relevant to designers of HMI systems, to be installed
in rooms with appropriate ambient conditions (e.g. used for supervising systems).
This standard does not define rules for the design of static graphical symbols for diagrams as
provided in IEC 61082 and the ISO/IEC 81714 series or for icons and graphical symbols for
use on equipment as provided in IEC 60417, ISO 7000 and in the ISO/IEC 11581 series.
This standard does not define a list indicating which existing graphical symbols are available
to be used to represent objects in their operational states following the rules established in
this standard.
REPRESENTATION OF STATES OF
OBJECTS BY GRAPHICAL SYMBOLS
1 Scope
This international standard provides generic rules for the representation of states of objects
by graphical symbols standardized in IEC 60617, ISO 14617, IEC 60417, for example, and for
future graphical symbols included in these standards.
NOTE 1 Graphical symbols in IEC 60617, ISO 14617 and IEC 60417 are mostly presented with a single graphic,
not representing the different operational states of objects occurring during their life cycle, e.g. in operation, of the
object that the graphical symbol represents.
NOTE 2 The graphical symbols in IEC 60617 and ISO 14617 are – at the time of writing of the first edition of this
standard – generally shown in the operational state “not energized”.
NOTE 3 Within the different periods of an object within its life cycle, i.e. design, manufacturing, operation,
disposal, each period counts with different states. However, this standard focuses only on those states occurring
during the active operation period from an object put into service until it is taken out of service.
This horizontal standard has the purpose of:
• ensuring the coherence of the corpus of standardization documents;
• avoiding duplication of work and contradictory requirements.
The standard provides operational states of an object as examples that typically occur and
which need to be represented by standardized graphical symbols and defines generic rules to
be applied. It specifies which types of presentation facilities are recommended to present the
different operational states to humans.
States concerning the different types of alarm, their classification and management are not
dealt with in this standard.
This standard does neither define rules for the design of static graphical symbols for
diagrams as provided in IEC 61082 and the ISO/IEC 81714 series nor for icons and graphical
symbols for use on equipment as provided in IEC 60417, ISO 7000 and in the ISO/IEC
11581 series.
This horizontal standard is primarily intended for use by technical committees in the
preparation of standards in accordance with the principles laid down in IEC Guide 108.
One of the responsibilities of a technical committee is, wherever applicable, to make use of
horizontal standards in the preparation of its publications. The content of this horizontal
standard will not apply unless specifically referred to or included in the relevant publications.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60073:2002, Basic and safety principles for man-machine interface, marking and
identification – Coding principles for indicators and actuators

– 8 – IEC 62744:2014 © IEC 2014
IEC 60417, Graphical symbols for use on equipment. Available from http://www.graphical-
symbols.info/equipment
IEC 60617, Graphical symbols for diagrams. Available from IEC 60617 – Graphical Symbols
for Diagrams
IEC 61360-4, Standard data element types with associated classification scheme for electric
components – Part 4: IEC reference collection of standard data element types and component
classes. Available from http://std.iec.ch/iec61360
IEC Guide 108, Guidelines for ensuring the coherency of IEC publications - Application of
horizontal standards
ISO 14617 (all parts), Graphical symbols for diagrams;
ISO 7000, Graphical symbols for use on equipment – Index and synopsis; Registered symbols
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
graphical symbol
visually perceptible figure with a particular meaning used to transmit information
independently of language
Note 1 to entry: The graphical symbol may represent objects, such as products, functions or requirements for
manufacturing and use, quality control, etc.
Note 2 to entry: A graphical symbol is not to be confused with the simplified representation of products which is
normally drawn to scale and which can look like a picture.
[SOURCE: ISO 81714-1:2010, 3.1, modified – "and use" added in Note 1, "…like a graphical
symbol" replaced by "…like a picture" in Note 2.]
3.1.2
presentation set (of objects)
set of discrete presentation forms of a graphical symbol representing an object, each form
representing a defined operational state of the object, used for dynamic presentation
Note 1 to entry: The different forms of a graphical symbol are derived from a basic graphical symbol, such
forming a symbol family.
Note 2 to entry: According to IEC 61082-1 a graphical symbol will represent the object in a de-energized
operational state, i.e. in the position OFF.
Note 3 to entry: This includes audible and visible but not tangible (e.g. BRAILLE) presentation facilities
3.1.3
operational state
defined states within the being-in-service period which an object can have
3.1.4
acoustic signal; auditory signal
message conveyed by means of tone, frequency and intermittency, emanating from a sound
source
[SOURCE: IEC 60073:2002, 3.2.1]

3.1.5
tactile signal
message conveyed by means of vibration, force, surface roughness, contour or position
[SOURCE: IEC 60073:2002, 3.2.2]
3.1.6
visual signal
message conveyed by means of brightness, contrast, colour, shape, size or position
Note 1 to entry: Flashing visual characteristics may be used to attract attention, and especially to give additional
emphasis
[SOURCE: IEC 60073:2002, 3.2.3, modified – Note 1 to entry added.]
3.1.7
actuator
part of the actuating system which receives a human actuating action
Note 1 to entry: For the purposes of this standard, the actuator in the case of an interactive screen display is
considered to be that part of the screen display which represents the actuator functions.
[SOURCE: IEC 60447:2004, 3.1, modified – The notes have been replaced by Note 1 to
entry.]
3.1.8
man-machine interface
MMI
human-machine interface
HMI
part of the equipment intended to provide a direct means of communication between the
operator and the equipment, and which enables the operator to control and monitor the
operation of the equipment
Note 1 to entry: Such parts may include manually operated actuators, indicators and screens.
[SOURCE: IEC 60447:2004, 3.3, modified – addition of "human-machine interface (HMI)".]
3.1.9
brightness
attribute of a visual sensation according to which an area appears to emit more or less light
[SOURCE: IEC 60050-845:1987, 845-02-28]
3.1.10
contrast
1) in the perceptual sense: Assessment of the difference in appearance of two or more parts
of a field seen simultaneously or successively (hence: brightness contrast, lightness
contrast, colour contrast, simultaneous contrast, successive contrast, etc.)
2) in the physical sense: Quantity intended to correlate with the perceived brightness
contrast, usually defined by one of a number of formulae which involve the luminance of
the stimuli considered, for example: ∆L / L near the luminance threshold or L /L for much
1 2
higher luminance
[SOURCE: IEC 60050-845:1987, 845-02-47]

– 10 – IEC 62744:2014 © IEC 2014
3.1.11
perceived colour
colour
attribute of visual perception consisting of any combination of chromatic and achromatic
content. This attribute can be described by chromatic colour names such as yellow, orange,
brown, red, pink, green, blue, purple, etc., or by achromatic colour names such as white, grey,
black, etc., and qualified by bright, dim, light, dark, etc., or by combinations of such names.
Note 1 to entry: Perceived colour depends on the spectral distribution of the colour stimulus, on the size, shape,
structure and surround of the stimulus area, on the state of adaptation of the observer's visual system, and on the
observer's experience of the prevailing and similar situations of observation.
Note 2 to entry: See Notes 1 and 2 to IEC 60050-845:1987, 845-03-01.
Note 3 to entry: Perceived colour may appear in several modes of colour appearance. The names for various
modes of appearance are intended to distinguish among qualitative and geometric differences of colour
perceptions. Some of the more important terms of the modes of colour appearance are given in
IEC 60050-845:1987, 845-02-19, 20, 21.
Other modes of colour appearance include film colour, volume colour, illuminant colour, body colour, and Ganzfeld
colour. Each of these modes of colour appearance may be further qualified by adjectives to describe combinations
of colour or their spatial and temporal relationships. Other terms that relate to qualitative differences among
colours perceived in various modes of colour appearance are given in IEC 60050-845:1987, 845-02-22, 23, 24, 25.
[SOURCE: IEC 60050-845:1987, 845-02-18, modified (addition of "colour" to term)]
3.1.12
contrast sensitivity
S
c
reciprocal of the least perceptible (physical) contrast, usually expressed as L / ∆L, where L is
the average luminance and ∆L is the luminance difference threshold
Note 1 to entry: The value of contrast sensitivity S depends on the luminance and on the viewing conditions,
c
including the state of adaptation.
[SOURCE: IEC 60050-845:1987, 845-02-48]
3.1.13
spatial frequency
inverse of the period of a repetitive spatial phenomenon. The dimension of the spatial
frequency is inverse length.
[SOURCE: IEC 62220-1:2003, 3.15]
3.1.14
signal light
object or apparatus designed to emit a light signal
[SOURCE: IEC 60050-845:1987, 845-11-05]
3.1.15
object
entity treated in a process of development, implementation, usage and disposal
Note 1 to entry: The object may refer to a physical or non-physical “thing”, i.e. anything that will exist, exists or
existed.
Note 2 to entry: The object has information associated to it.
[SOURCE: IEC 81346-1:2009, 3.1, Note 1 to entry modified]

3.1.16
instructions for use
information provided by the supplier of a product to the user, containing all the necessary
provisions to convey the actions to be performed for the safe and efficient use of the product
Note 1 to entry: Instructions for use of a single product comprise one or more documents.
[SOURCE: IEC 82079-1:2012, 3.19]
3.1.17
process flow diagram
representation of a process or a process plant by means of graphical symbols, interconnected
by flow lines; the graphical symbols represent equipment and the lines represent flows of
mass and energy or energy carriers
[SOURCE: IEC 61355-D00042 (2008-04), modified – "The process flow diagram depicts" was
replaced by "representation of".]
3.1.18
continuous process
process in which an item is produced without interruption
Note 1 to entry: Although chemicals are mainly manufactured in batches, this is still considered a continuous
process since the variables that control the process can be varied continuously.
3.1.19
glare
condition of vision in which there is discomfort or a reduction in the ability to see details or
objects, caused by an unsuitable distribution or range of luminance, or to extreme contrasts
[SOURCE: IEC 60050-845:1987, 845-02-52]
3.1.20
achromatic (perceived) colour
perceived colour devoid of hue. The colour names white, grey and black are commonly used
or, for transmitting objects, colourless and neutral
[SOURCE: IEC 60050-845:1987, 845-02-26, modified – Part 2 has been deleted.]
3.1.21
state
mode of being
3.1.22
signal word
word that calls attention to a product safety label and designates a category of risk
[SOURCE: ISO 3864-2:2004, 3.14]
3.1.23
safety colour
colour with special properties to which a safety meaning is attributed
[SOURCE: ISO 17724:2003, 66]
– 12 – IEC 62744:2014 © IEC 2014
3.1.24
visual danger signal
visual signal indicating imminent onset or actual occurrence of a dangerous situation,
involving risk of personal injury or equipment disaster, and requiring some human response to
eliminate or control the danger or requiring other immediate action
Note 1 to entry: A distinction is made between two types of visual danger signal: visual warning signal and visual
emergency signal.
[SOURCE: ISO 11428:1996, 3.1]
3.1.25
visual warning signal
visual signal indicating the imminent onset of a dangerous situation requiring appropriate
measure for the elimination or control of the danger
[SOURCE: ISO 11428:1996, 3.1.1]
3.1.26
visual emergency signal
visual signal indicating the beginning or the actual occurrence of a dangerous situation
requiring immediate action
[SOURCE: ISO 11428:1996, 3.1.2]
3.2 Abbreviations
SCADA Supervision, Control And Data Acquisition
HMI Human Machine Interface
CAE Computer Aided Engineering
4 General
Visual displays are widely used for human interaction for many types of products and
systems. Typically for the modern type of display is that the graphic representation of an
object is not static but will react dynamically due to the automatic behaviour of the
product/system or due to manual actions by the operator leading to change, for example
colour, shape, etc. In the case that standardized graphical symbols, as presented in
IEC 60617, ISO 14617, or IEC 60417, are used on these displays, it is often required that the
dynamic behaviour of the represented object needs to be reflected by an identified change of
the related graphical symbol.
Some examples including time- and state-dependent graphical symbols for use on screens
and displays are:
– icons used on screens of personal computers, mobile equipment, mobile phones and
touch screens;
– dynamic graphical symbols used on console and monitor screens of Human-Machine
Interface (HMI) systems and Supervisory Control and Data Acquisition System (SCADA);
– icons and graphical symbols used in “interactive” documents, such as instruction for use
and process flow diagrams, presented in electronic form, and
– engineering tools, for example Computer Aided Engineering tool (CAE), including test
features with visual presentation of simulated or actual engineering result.

5 Reasons for dynamic representation of objects
5.1 General
This clause describes the reasons for a change of the presentation form of a graphical symbol
in order to indicate to the human which operational state of the object is represented.
5.2 Change of state of an object in the supervised process
The reason for using a dynamic graphical symbol is the case where the graphical symbol is
used in a supervisory system to represent an object, which, by changing its operational state,
will influence the supervised process. This is applicable for SCADA system and other
industrial processes like process control systems, etc.
It is recognized that even if the supervision basically uses only two states (e.g. ON/OFF) it is
required also to indicate the other occurring states.
Table 1 provides examples of generically defined operational states of an object.
Table 1 – Generic operational states used during
operation of an object (informative / exemplary)
Nr. Term Definition
1 OFF; DISCONNECTED state of an object de-energized, passive or not running
NOTE 1 The term OFF MODE is used in the context of describing the state
of an object concerning its power demands (see IEC 62542), and is not
corresponding to the operational state defined in this standard.
NOTE 2 The term DISCONNECTED is used in the context of describing the
state of an object concerning its power demands (see IEC 62542), and does
not correspond to the operational state defined in this standard.
2 CLOSING DOWN state of an object preparing for the OFF state
NOTE This can for example be cleaning the process details of the object so
it can be used for processing again the next day. This can be automatically or
manually performed
3 STOPPED state of a process manually or automatically aborted and made passive or not
running
4 FINISHED state of a process having fulfilled its assigned task and made de-energized,
passive or not running
5 SELECTED state of an object chosen and waiting for a command
NOTE After execution of the command, the operational state SELECTED is
finished. If the command is not executed within a defined period of time, the
selected object will return into the operational state it had before the last
selection occurred. For a new action the object needs to be selected again.
6 COMMAND state of an object having received a check back indication confirming that the
ACKNOWLEDGED actual action command for changing the operational state of the object has
been accepted
NOTE The accepted action is based on the previous command for changing
the operational state of the object.
7 IN TRANSITION state of an object having received an accepted command for execution
NOTE The transition period is finished when the object has reported that it
has changed from its previous state.
8 ON state of an object energized, active or running.
NOTE The term ON MODE is used in the context of describing the state of
an object concerning power demands (see IEC 62542), and is not
corresponding to the operational state defined in this standard.
9 AUTO the object (with its sub-objects) is under automatic control
10 MANUAL the object (with its sub-objects) is under manual control

– 14 – IEC 62744:2014 © IEC 2014
Nr. Term Definition
11 STEPPING the stepping of a step by step sequence for an object is under manual control
12 HOMERUN the step by step sequence of an object is brought back to its home/start step
13 UNDER state of an object (for a specified time) not available due to planned or
MAINTENANCE unplanned maintenance or repair activities
14 OUT OF SERVICE state of an object taken by intention out of operation
15 FAULTY state of an object taken out of service by manual or automatic means for
malfunctioning caused by technical troubles of the object itself or of
controlling or supervising other objects
16 NO INFORMATION  state of an object encountered with communication problems
NOTE The term NO INFORMATION implies that there is at a given point of
time none, no confirmed or no secured information about the actual status of
the object available.
17 MANUALLY state of an object previously encountered with communication problems and
ENFORCED enforced by the operator into a specified operational state, either ON or OFF
18 COLD STAND-BY state of an object prepared to be put into operation within a defined period of
time
state of an object preparing itself for operation
19 WARM-UP
NOTE This can for example be a state before entering HOT STAND-BY.
20 HOT STAND-BY; IDLE state of an object energized and ready for immediate operation without
MODE interruption of the ongoing process
NOTE IEC 62542:2013, 5.13 defines "idle mode" as the "condition during
which the equipment can promptly provide a primary function but is not doing
so".
NOTE IEC 62542 provides additional stages related to power consumption of equipment.

The operational states as given in Table 1, Table 2 and Table 3 are to be understood as
examples out of the variety of possibilities of operational states and not representing an
exhaustive list. There may exist different terms for the listed operational states, however the
listed terms in this international standard are considered to serve as preferred terms. Other
terms should be considered synonyms.
If the listed operational states are used in practice, then the preferred terms and definitions
shall apply as given in Table 1, Table 2 and Table 3 in conjunction with the graphical symbol
in order to avoid multiplicity of operational states with identical meanings.
The different states provided in this standard are presented using upper-case Latin letters.
Additional operational states may be defined according to the needs of specific object types.
5.3 Operators command/action
In an interactive system with an operator/user interface using a display with graphical
symbols, it is required to indicate the action taken by the operator. A typical action is the
selection of an object for further action. However, the time difference between the selection of
an object for further action and the later possibly executed command to change the state
needs to be indicated. The time lapse between the command for execution of the object by an
operator to change its state via the command acknowledgment and the new operational state
of the current object has to be differently presented, such as indicating the different transition
periods (see also Table 1).
If, having selected an object for further action the command action will not executed within a
given time period, then the selection of the object will be set inactive and the previous shown
graphical symbol will apply again. For a new action the object needs to be selected again.

Between the point in time of selecting an object for further action, the following command and
the check back (providing the information that the intended change became effective) is a
transition process and may involve different actions of, for example, a SCADA system,
considering safety aspects which might have the need to be reflected, for example changing a
breaker from OFF into the ON position starting with Object selection, Command execution,
Command acknowledgement and Check back indication, indicating the new state.
A typical sequence of “selection before execute” is described in Figure 1.
OFF SELECTED OFF SELECTE TRANSITION ON

Trans : 1 Trans : 2
t
t t t t t t
0 1 2 3 4 5
IEC
NOTE It is assumed that once an object has been selected for action and no command will be executed within the
specified time period t , the state will return to the previous one, i.e. OFF. This is the case between the steps t
and t . The time t -t is less than the time t -t

1 3 2 1 0
Figure 1 – Example of changing the operational state from OFF to ON
Change of operational states of objects typically depends on the operator’s actions, such as
changing state from OFF to ON or vice versa. The graphical symbol representing the object
may optionally be accompanied by information indicating the type of control executed in
conjunction with the relevant objects. For example the additional information “Manual” or
“Automatic”, “Local control” or “Remote control” should be indicated.
5.4 Time controlled activities
The form of presentation of a graphical symbol may be time controlled.
The time control may be set to:
• change the form periodically;
• change the form at a specified period of time;
• change the form with a time delay following an activity.
Applications with time-controlled visual changes may optionally indicate the specified time in
conjunction with the relevant state representation. Either the elapsed time or the remaining
time is indicated depending upon process needs. Once a type of time presentation is chosen
within an application, it shall be used consistently for safety reasons within that application.
5.5 Sporadic change
The form of presentation of a graphical symbol may be set to change sporadically as a
random time set and be changed due to manual or automatized process activities, related to a
supervised object or system.
– 16 – IEC 62744:2014 © IEC 2014
6 Area of application
6.1 General
Dynamic presentations of graphical symbols are used in many types of user interfaces, for
example, computer screens, video display units and graphical displays on products. The form
of presentation of the graphical symbols and its associated standardized rules shall be
irrelevant of the systems where they will be used.
For better understanding of the usage of this standard this clause includes some examples of
the context in which the dynamic presentation of the standardized graphical symbols are
intended to be used.
6.2 SCADA user interface
For supervision and control of electric power systems SCADA systems are often used. The
HMI used for SCADA and similar systems will typically display the system in a single line-
presentation with graphical symbols of the same type as used in drawings.
The graphical symbols applicable in SCADA systems often use different presentation forms
indicating different operational
...