IEC 62974-1:2024

IEC 62974-1 ®
Edition 2.0 2024-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Monitoring and measuring systems used for data collection, aggregation and
analysis –
Part 1: Device requirements
Systèmes de surveillance et de mesure utilisés pour la collecte, l’agrégation et
l'analyse de données –
Partie 1: Exigences relatives aux dispositifs
All rights reserved. Unless otherwise specified, 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
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews, graphical symbols and the glossary.
committee, …). It also gives information on projects, replaced With a subscription you will always have access to up to date
and withdrawn publications. content tailored to your needs.

IEC Just Published - webstore.iec.ch/justpublished
Electropedia - www.electropedia.org
Stay up to date on all new IEC publications. Just Published
The world's leading online dictionary on electrotechnology,
details all new publications released. Available online and once
containing more than 22 500 terminological entries in English
a month by email.
and French, with equivalent terms in 25 additional languages.

Also known as the International Electrotechnical Vocabulary
IEC Customer Service Centre - webstore.iec.ch/csc
(IEV) online.
If you wish to give us your feedback on this publication or need

further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC -  IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez
La recherche avancée permet de trouver des publications IEC gratuitement tous les aperçus des publications, symboles
en utilisant différents critères (numéro de référence, texte, graphiques et le glossaire. Avec un abonnement, vous aurez
comité d’études, …). Elle donne aussi des informations sur les toujours accès à un contenu à jour adapté à vos besoins.
projets et les publications remplacées ou retirées.

Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
Le premier dictionnaire d'électrotechnologie en ligne au monde,
Restez informé sur les nouvelles publications IEC. Just
avec plus de 22 500 articles terminologiques en anglais et en
Published détaille les nouvelles publications parues.
français, ainsi que les termes équivalents dans 25 langues
Disponible en ligne et une fois par mois par email.
additionnelles. Egalement appelé Vocabulaire

Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC 62974-1 ®
Edition 2.0 2024-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Monitoring and measuring systems used for data collection, aggregation and

analysis –
Part 1: Device requirements
Systèmes de surveillance et de mesure utilisés pour la collecte, l’agrégation et

l'analyse de données –
Partie 1: Exigences relatives aux dispositifs

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20  ISBN 978-2-8322-9483-3

– 2 – IEC 62974-1:2024 © IEC 2024
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
3.1 General definitions . 10
3.2 Definitions related to devices . 11
3.3 Definitions related to inputs and outputs . 12
4 Normal environmental conditions . 13
5 Ratings . 13
6 Requirements for design and construction . 13
6.1 General . 13
6.2 General architecture of devices . 13
6.3 Product classification . 14
6.4 General data processing . 15
6.5 Requirements on minimum functions embedded in devices . 15
6.5.1 General requirements . 15
6.5.2 Management of digital and/or analogue input(s) or output(s) . 16
6.5.3 Communication connectivity features . 17
6.5.4 Data time stamping . 17
6.5.5 Management of logged data. 17
6.5.6 Management of aggregated data . 18
6.5.7 Analysis of aggregated data . 18
6.5.8 Local visualisation on an HMI . 18
6.5.9 Configuration management . 18
6.6 Safety requirements . 18
6.6.1 Protection against electrical hazards . 18
6.6.2 Protection against mechanical hazards . 19
6.6.3 Protection against other hazards . 19
6.6.4 Safety-related security (cybersecurity) . 19
6.7 EMC requirements . 20
6.7.1 Immunity requirements . 20
6.7.2 Emission requirements . 21
6.8 Climatic requirements . 21
6.9 Mechanical requirements . 21
6.9.1 Vibrations . 21
6.9.2 Shocks . 21
6.9.3 Enclosure robustness (IK code) . 21
6.9.4 Degree of protection by enclosures (IP code) . 21
6.10 Requirements for marking and documentation . 22
6.10.1 General . 22
6.10.2 Device marking . 22
6.10.3 Documentation . 22
7 Type tests . 23
7.1 Performance criteria for type tests . 23
7.2 Safety tests . 24

7.3 EMC tests plan . 24
7.3.1 General . 24
7.3.2 Configuration of EUT during testing . 24
7.3.3 Operation conditions of EUT during testing . 25
7.3.4 Specification of functional performance . 25
7.3.5 Test description . 25
7.3.6 EMC test result and test report . 25
7.3.7 EMC instructions for use . 25
7.4 Climatic tests . 25
7.5 Mechanical tests . 26
7.5.1 Vibration . 26
7.5.2 Shock tests . 26
7.5.3 Degree of protection provided by enclosures for electrical equipment
against external mechanical impacts (IK code) . 26
7.5.4 Degree of protection by enclosure (IP code) . 26
8 Routine tests . 26
Annex A (informative) Example of system architectures . 27
Annex B (informative) Example of device processing . 29
Bibliography . 30

Figure 1 – Plan-Do-Check-Act Cycle . 7
Figure 2 – General architecture of devices . 14
Figure A.1 – Basic local monitoring and measuring system architecture . 27
Figure A.2 – Advanced local monitoring and measuring system architecture . 27
Figure A.3 – Remote monitoring and measuring system architecture . 28
Figure B.1 – General data processing of the general device . 29

Table 1 – Normal environmental conditions . 13
Table 2 – Devices classification . 15
Table 3 – List of minimum functions embedded in devices . 16
Table 4 – Additional EMC tests for class 2 devices . 20
Table 5 – Minimum IP requirements . 21
Table 6 – Marking to apply to devices . 22
Table 7 – Specific performance criteria . 23
Table 8 – Climatic requirements . 25

– 4 – IEC 62974-1:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MONITORING AND MEASURING SYSTEMS USED
FOR DATA COLLECTION, AGGREGATION AND ANALYSIS –

Part 1: Device requirements
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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 62974-1 has been prepared by IEC technical committee 85: Measuring equipment for
electrical and electromagnetic quantities. It is an International Standard.
This second edition cancels and replaces the first edition published in 2017. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the performance criteria have been reviewed;
b) EMC and safety requirements have been improved;
c) mechanical requirements have been clarified and amended.

The text of this International Standard is based on the following documents:
Draft Report on voting
85/920/FDIS 85/929/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
A list of all parts in the IEC 62974 series, published under the general title Monitoring and
measuring systems used for data collection, aggregation and analysis, can be found on the IEC
website.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The "colour inside" logo on the cover page of this document 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 62974-1:2024 © IEC 2024
INTRODUCTION
The use of electrical energy needs to be optimised worldwide to increase the efficient use of
available energy sources, for enhanced competitiveness, and for reducing greenhouse gas
emissions and other related environmental impacts.
Efficient use of energy sources implies better energy management leading to a necessary
improvement of energy performance, particularly in terms of efficiency, use and consumption.
Aggregating energy data and ensuring its availability is key to providing an energy management
system for organizations.
Energy management systems described in documents such as ISO 50001, ISO 50002,
ISO 50006, refer to the measurement of energy as an important improvement of energy
performance.
ISO 50001:2018 includes a requirement to "implement an energy data collection plan […] and
its measurement and monitoring equipment" to enable the organization to demonstrate energy
performance improvement.
Figure 1 shows the link between the ISO 50001:2018 PDCA model and the continuous
improvement of this data collection.
In the context of energy management, the Plan-Do-Check-Act (PDCA) approach (see Figure 1)
can be outlined as follows:
– Plan: understand the context of the organization, establish an energy policy and an energy
management team, consider actions to address risks and opportunities, conduct an energy
review, identify significant energy uses (SEUs) and establish energy performance indicators
(EnPIs), energy baseline(s) (EnBs), objectives and energy targets, and action plans
necessary to deliver results that will improve energy performance in accordance with the
organization's energy policy.
– Do: implement the action plans, operational and maintenance controls, and communication,
ensure competence and consider energy performance in design and procurement.
– Check: monitor, measure, analyse, evaluate, audit and conduct management review(s) of
energy performance and the EnMS.
– Act: take actions to address nonconformities and continually improve energy performance
and the EnMS.
[SOURCE: ISO 50001:2018, reproduced with the permission of the authors]
Figure 1 – Plan-Do-Check-Act Cycle
IEC 60364-8-1 provides electrical installation rules for overall energy efficiency functional
aspects. It defines requirements, measures and recommendations for the design, erection,
operation and verification of all types of low voltage electrical installation including local
production and storage of energy for optimizing the overall efficient use of electricity. In
particular, it provides recommendations and requirements for the implantation of measurement
and data logging devices in low voltage electrical installations, as defined in IEC 62974-1, to
improve electrical energy efficiency (EEE) and make energy demand forecasts.
What is not known cannot be changed, and what is not measured is not known. Consequently,
there is an increasing need to measure energy within the installations to:
• identify energy saving opportunities; or
• monitor energy performance indicators; or
• educate users.
The measurement data can be gathered manually by employees or automatically by dedicated
devices.
Manual data collection can be a restrictive and complicated process to implement. In such a
case, measurements would need to be collected by employees at a defined frequency, with a
provision for risks of absences being made (vacation, sick leave, etc.), provided the
measurements are relevant (number of measurement points to collect) and provided
measurements can be relatively coherent (time synchronicity).
This is why data collection should be performed on a fixed schedule and the measurement data
relevant to assess the required performance. Commonly, to avoid manual data collection,
dedicated devices are used for collection, aggregation and sometimes analysis of measured
data. These devices are directly linked to the different measurement devices in the installation
to upload or download the energy data. Some typical architectures are given in Annex A.

– 8 – IEC 62974-1:2024 © IEC 2024
MONITORING AND MEASURING SYSTEMS USED
FOR DATA COLLECTION, AGGREGATION AND ANALYSIS –

Part 1: Device requirements
1 Scope
This part of IEC 62974 specifies product and performance requirements for devices that fall
under the heading of "monitoring and measuring systems used for data collection, aggregation
and analysis", for industrial, commercial, and similar use rated below or equal to 1 kV AC and
1,5 kV DC.
These devices are fixed and are intended to be used indoors as panel-mounted devices, or as
modular devices fixed on a DIN rail, or as housing devices fixed on a DIN rail, or as devices
fixed by other means inside a cabinet.
These devices are used to upload or download information (energy measured on loads, power
metering and monitoring data, temperature information, etc.), mainly for energy efficiency
purposes. These devices are known as energy servers (ESE), energy data loggers (EDL), data
gateways (DGW) and I/O data concentrators (IODC) and are grouped together under the family
name of Data Management Devices (DMD).
NOTE These systems are embedded or can be connected to a software application capable of consolidating data
and delivering automatic analysis. Automatic analysis can include calculation of energy baselines or energy
performance indicators as requested for the energy management system required by ISO 50001 or can be used
during energy audits as defined in ISO 50002, or can be used in electrical energy efficiency management systems
(EEMS) for monitoring an installation complying with IEC 60364-8-1 for the efficient use of electricity. These devices
can also be used for certification according to labels such as LEED, BREEAM, HQE, etc.
This document does not cover:
• devices used only in the consumer market (living quarters) or household;
• devices used in the smart metering infrastructure (e.g. smart meters);
• devices used in the smart grid infrastructure;
• devices used as IT servers in the information technology business;
• power metering and monitoring devices (PMD);
• I/O data concentrators already covered by a specific product standard;
• communication protocols and interoperability;
• power quality instruments (PQI);
• software used for the data collection and analysis of the power quality for the supply side.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-2-1:2007, Environmental testing – Part 2-1: Tests – Test A: Cold
IEC 60068-2-2:2007, Environmental testing – Part 2-2: Tests – Test B: Dry heat

IEC 60068-2-6:2007, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-14:2009, Environmental testing – Part 2-14 – Tests – Test N: Change of
temperature
IEC 60068-2-27:2008, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 60068-2-78:2012, Environmental testing – Part 2-78 – Tests – Test Cab: Damp heat, steady
state
IEC 60529:1989, Degrees of protection provided by enclosures (IP Code)
IEC 60529:1989/AMD1:1999
IEC 60529:1989/AMD2:2013
IEC 61000-4-4:2012, Electromagnetic compatibility (EMC) – Part 4-4: Testing and
measurement techniques – Electrical fast transient/burst immunity test
IEC 61000-4-5:2014, Electromagnetic compatibility (EMC) – Part 4-5: Testing and
measurement techniques – Surge immunity test
IEC 61000-4-5:2014/AMD1:2017
IEC 61000-4-8:2009, Electromagnetic compatibility (EMC) – Part 4-8: Testing and
measurement techniques – Power frequency magnetic field immunity test
IEC 61000-4-11:2020, Electromagnetic compatibility (EMC) – Part 4-11: Testing and
measurement techniques – Voltage dips, short interruptions and voltage variations immunity
tests for equipment with input current up to 16 A per phase
IEC 61010-1:2010, Safety requirements for electrical equipment for measurement, control, and
laboratory use – Part 1: General requirements
IEC 61010-1:2010/AMD1:2016
IEC 61131-2:2017, Industrial-process measurement and control – Programmable controllers –
Part 2: Equipment requirements and tests
IEC 61326-1:2020, Electrical equipment for measurement, control and laboratory use – EMC
requirements – Part 1: General requirements
IEC 62052-11:2020, Electricity metering equipment – General requirements, tests and test
conditions – Part 11: Metering equipment
IEC 62262:2002, Degrees of protection provided by enclosures for electrical equipment against
external mechanical impacts (IK code)
IEC 62262:2002/AMD1:2021
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp

– 10 – IEC 62974-1:2024 © IEC 2024
3.1 General definitions
3.1.1
energy data
quantities related to the management of energy measured in industrial, commercial and similar
plants, including energy consumption, relevant variables and electrical parameters
Note 1 to entry: Energy consumption refers to the various forms of energy (electricity, fossil fuels, steam, heat,
compressed air, etc.).
Note 2 to entry: Electrical parameters refer to power, voltage, current, power factor, THD, harmonics, etc., which
can also be monitored.
3.1.2
energy performance
measurable result(s) related to energy efficiency, energy use and energy consumption
Note 1 to entry: Energy performance can be measured against the organization's objectives, energy targets and
other energy performance requirements.
Note 2 to entry: Energy performance is one component of the performance of the energy management system.
[SOURCE: ISO 50001:2018, 3.4.3]
3.1.3
energy performance indicator
EnPI
measure or unit of energy performance, as defined by the organization
Note 1 to entry: EnPI(s) can be expressed by using a simple metric, ratio, or a model, depending on the nature of
the activities being measured.
Note 2 to entry: See ISO 50006 for additional information on EnPI(s).
[SOURCE: ISO 50001:2018: 3.4.4]
3.1.4
relevant variable
quantifiable factor that significantly impacts energy performance and routinely changes
Note 1 to entry: Significance criteria are determined by the organization.
EXAMPLE Weather conditions, operating conditions (indoor temperature, light level), working hours, production
output.
[SOURCE: ISO 50001:2018, 3.4.9]
3.1.5
energy baseline
EnB
quantitative reference(s) providing a basis for comparison of energy performance
Note 1 to entry: An energy baseline is based on data from a specified period of time and/or conditions, as defined
by the organization.
Note 2 to entry: One or more energy baselines are used for determination of energy performance improvement, as
a reference before and after, or with and without implementation of energy performance improvement actions.
Note 3 to entry: See ISO 50015 for additional information on measurement and verification of energy performance.
Note 4 to entry: See ISO 50006 for additional information on EnPIs and EnBs.
[SOURCE: ISO 50001:2018, 3.4.7]

3.1.6
energy efficiency
ratio or other quantitative relationship between an output of performance, service, goods,
commodities, or energy and an input of energy
EXAMPLE Conversion efficiency; energy required/energy consumed.
Note 1 to entry: Both input and output should be clearly specified in terms of quantity and quality and be
measurable.
[SOURCE: ISO 50001:2018, 3.5.3]
3.1.7
electrical energy efficiency
EEE
system approach for optimizing the efficiency of electricity usage
Note 1 to entry: Energy efficiency improvement measures take into account the following considerations:
– both the consumption (kWh) and the price of electricity;
– technology;
– environmental impact.
[SOURCE: IEC 60364-8-1:2019, 3.1.7]
3.1.8
electrical energy management system
EEMS
system monitoring, operating, controlling and managing energy resources and loads of the
installations
[SOURCE: IEC 60364-8-1:2019, 3.2.1]
3.1.9
data retention
capability to store data for a specified duration within a powered or unpowered device
3.1.10
data backup
capability to store a copy of data stored in a device for an unlimited duration
Note 1 to entry: The copied data is supposed to provide data in the event of a device failure leading to data loss.
3.1.11
human machine interface
HMI
equipment function designed to present information output to and accept information from the
operator, thus making the human operator an integral part of a process
3.2 Definitions related to devices
3.2.1
energy server
ESE
device used for the computation and retention of energy data, relevant variables, and
visualisation through a local display or remote access in electrical distribution systems of
industrial, commercial and similar plants

– 12 – IEC 62974-1:2024 © IEC 2024
3.2.2
energy data logger
EDL
device used for logging and exporting information to networks in electrical distribution systems
of industrial, commercial and similar plants
3.2.3
data gateway
DGW
device used for transmission of information between networks in electrical distribution systems
of industrial, commercial and similar plants
3.2.4
I/O data concentrator
IODC
device used for collection of digital and/or analogue energy data in electrical distribution
systems of industrial, commercial and similar plants
3.2.5
measuring device
device able to measure energy data
3.2.6
monitoring and measuring system
system used for metering, measuring, collecting, concentrating and analysing energy data
3.3 Definitions related to inputs and outputs
3.3.1
pulse
wave that departs from an initial level for a limited duration of time and ultimately returns to the
original level
[SOURCE: IEC 62052-11:2020, 3.2.4]
3.3.2
pulse input
pulse for receiving pulses related to an energy measurement (electricity, gas, water, etc.)
[SOURCE: IEC 62052-11:2020, 3.2.8, modified – "related to an energy measurement
(electricity, gas, water, etc.)" added.]

4 Normal environmental conditions
Devices are intended to be used in the normal environmental conditions listed in Table 1.
Table 1 – Normal environmental conditions
Environmental parameters Storage and transport Indoor operation
a, c
For K55 class: For K55 class:
Ambient temperature: limit range of operation
−25 °C to +70 °C −5 °C to +55 °C
e e
For K70 class : For K70 class :
−40 °C to + 70 °C −25 °C to +70 °C
e e
For Kx class : For Kx class :
Above +70 °C and/or Above +70 °C and/or
d d
under −40 °C under −25 °C
b b
Relative humidity: 24 h average
from 5 % to 95 % from 5 % to 95 %
Solar radiations Negligible Negligible
Wind-driven precipitation (snow, hail, etc.) Negligible Negligible

Air pollution by salt, smoke, corrosive/flammable gas, vapours Negligible Negligible
Altitude --- ≤ 2 000 m
a
See definition. Temperature may be lower on the front face of panel mounted instruments.
b
No condensation or ice is taken into consideration.
c
Limit temperatures are extreme temperatures. The device is not supposed to stay at limit T° during 100 % of
the time.
d
Limits are to be defined by the manufacturer according to the application.
e
Kx stands for extended conditions.
NOTE More severe environmental conditions can be needed for special applications.

5 Ratings
No requirements.
6 Requirements for design and construction
6.1 General
Devices shall comply with the requirements specified in this Clause 6.
6.2 General architecture of devices
Energy servers (ESE), energy data loggers (EDL), data gateways (DGW) and I/O data
concentrators (IODC) are usually composed of one or several functional blocks as defined in
Figure 2.
– 14 – IEC 62974-1:2024 © IEC 2024

Figure 2 – General architecture of devices
NOTE Downstream and upstream communication can be managed with the same port.
6.3 Product classification
Devices shall be classified according to the following criteria.
– Kind of device:
• IODC: I/O data concentrators;
• DGW: data gateways;
• EDL: energy data logger;
• ESE: energy servers.
– Temperature class:
• K55 class;
• K70 class.
– Device performance class:
• class 1: for devices intended to manage (collect, store, transmit) energy data within the
EMC environmental conditions described in 6.7;
• class 2: for devices intended to manage (collect, store, transmit) energy data within the
EMC environmental conditions described in 6.7, including additional EMC test
requirements.
Devices shall be named according to the classification of Table 2.

Table 2 – Devices classification
Kind of device Class For devices intended For devices intended For devices intended
to work up to K55 to work up to K70 to work up to Kx
climatic environment climatic environment climatic environment
a
Energy I/O EIOC, Class 1, K55 EIOC, Class 1, K70 EIOC, Class 1, Kx
Class 1
concentrators
Data gateways Class 1 DGW, Class 1, K55 DGW, Class 1, K70 DGW, Class 1, Kx
b
DGW, Class 2, K55 DGW, Class 2, K70 DGW, Class 2, Kx
Class 2
Energy data logger Class 1 EDL, Class 1, K55 EDL, Class 1, K70 EDL, Class 1, Kx
Class 2 EDL, Class 2, K55 EDL, Class 2, K70 EDL, Class 2, Kx
Energy servers Class 1 ESE, Class 1, K55 ESE, Class 1, K70 ESE, Class 1, Kx
Class 2 ESE, Class 2, K55 ESE, Class 2, K70 ESE, Class 2, Kx
a
Class 2 is not necessary for IODC.
b
Since data gateways are not managing "logged data" or "aggregated date", they are not subject to the "data

retention" requirement.
6.4 General data processing
ESEs, EDLs, DGWs and IODCs are part of a general data processing system.
NOTE See example shown in informative Annex B. Further information is provided in Annex A.
6.5 Requirements on minimum functions embedded in devices
6.5.1 General requirements
ESEs, EDLs, DGWs and IODCs shall embed the mandatory functions defined in Table 3.
Table 3 specifies "M" (mandatory) and "O" (optional) functions. The mandatory or optional
functions that are implemented in the device, shall comply with the requirements within the
relevant subclauses of 6.5.
– 16 – IEC 62974-1:2024 © IEC 2024
Table 3 – List of minimum functions embedded in devices
Functions Requirement Requirement Requirement Requirement
for IODC for DGW for EDL for ESE
Management of I/O (see 6.5.2)
Collection of digital or analogue input(s) M O O O
Update of digital or analogue output(s) O O O O
Communication connectivity features (see
6.5.3)
Upstream connectivity M M M M
Downstream connectivity --- M M M
Time stamping (see 6.5.4)
Data time stamping --- O M M
Management of logged data (see 6.5.5)
Data logging --- --- M M
Logged data retention --- --- M M
Publication of logged data --- --- M M
Management of aggregated data (see 6.5.6)
Data aggregation --- --- --- M
Publication of aggregated data --- --- --- O
Aggregated data backup --- --- --- O
Analysis of aggregated data (see 6.5.7)
Simple energy efficiency applications --- --- --- M
Advanced energy efficiency applications --- --- --- O
HMI features (see 6.5.8)
Visualization on a local or remote display --- --- --- M
Key
M: mandatory
O: optional
---: not relevant
6.5.2 Management of digital and/or analogue input(s) or output(s)
6.5.2.1 General
Devices embedding this function shall comply with the relevant standards specified in 6.5.2.2
and 6.5.2.3.
6.5.2.2 Analogue input(s)/output(s)
Analogue inputs/outputs shall comply with IEC 61131-2:2017, 6.5.
NOTE 1 The currents of analogue input/outputs are usually 4 mA to 20 mA, or sometimes 0 mA to 20 mA.
NOTE 2 The voltages of analogue inputs/outputs are usually 0 V to 5 V, or sometimes 0 V to 10 V.
6.5.2.3 Pulse input(s)/output(s)
Pulse inputs/outputs shall comply with IEC 62052-11:2020, 5.9 and 5.8, respectively
(Functional requirements).
6.5.2.4 Digital input(s)/output(s)
There are no required standards to be met.
6.5.3 Communication connectivity features
Manufacturers shall document the behaviour of the device in the event of loss of downstream
or upstream communications. In particular, the manufacturer shall document how the loss of
communication is reported and/or recorded by the device, and what diagnostic information is
provided.
6.5.4 Data time stamping
Manufacturers shall document the resolution of data stamping.
Preferably, data is stamped as close as possible to when it has been measured.
Preferred data time stamps shall be UTC (Greenwich Mean Time); use of another format shall
be described.
Additional information, such as time zone or DST offset, may accompany the time stamp.
6.5.5 Management of logged data
6.5.5.1 Data logging
Devices shall log raw data and their associated information (zone, energy use, time stamp).
NOTE Local regulations can require minimum time duration of storage for the measurement data.
6.5.5.2 Logged data retention capability
Manufacturers shall document the data retention capabilities: number and time interval of
measurements retained during a specified time.
Devices embedding the logged data retention capability shall be able to retain logged data in
the absence of mains power during the specified retention time. Devices embedding this
function shall be able of continuing to operate during an upstream communication outage
without any loss of logged data during the specified retention time and without missing any data
coming from downstream communication.
Devices embedding the logged data retention capability shall be able to continue to operate
during an upstream communication outage without any loss of logged data during the specified
retention time and without missing any data coming from downstream communication during
the specified retention time.
Class 2 devices shall have a minimum specified retention time of 24 h.
6.5.5.3 Logged data
...