Safety of machinery - Electro-sensitive protective equipment - Part 2: Particular requirements for equipment using active opto-electronic protective devices (AOPDs)

IEC 61496-2:2020 specifies requirements for the design, construction and testing of electro-sensitive protective equipment (ESPE) designed specifically to detect persons as part of a safety-related system, employing active opto-electronic protective devices (AOPDs) for the sensing function. Special attention is directed to features which ensure that an appropriate safety-related performance is achieved. An ESPE can include optional safety-related functions, the requirements for which are given in Annex A of IEC 61496-1:2020 and of this document.
This document does not specify the dimensions or configurations of the detection zone and its disposition in relation to hazardous parts for any particular application, nor what constitutes a hazardous state of any machine. It is restricted to the functioning of the ESPE and how it interfaces with the machine.
Excluded from this document are AOPDs employing radiation at wavelengths outside the range 400 nm to 1 500 nm.
This document can be relevant to applications other than those for the protection of persons, for example, the protection of machinery or products from mechanical damage. In those applications, additional requirements can be necessary, for example, when the materials that are to be recognized by the sensing function have different properties from those of persons.
This document does not deal with electromagnetic compatibility (EMC) emission requirements.
IEC 61496-2:2020 cancels and replaces the third edition published in 2013. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Requirements and test procedures in Part 2 that were found to be common to all ESPEs have been moved to Part 1. Test procedures that are dependent on the sensing technology remain in Part 2.

Sécurité des machines - Équipements de protection électrosensibles - Partie 2: Exigences particulières pour un équipement utilisant des dispositifs protecteurs optoélectroniques actifs (AOPD)

L'IEC 61496-2:2020 définit les exigences de conception, de construction et d'essai d'équipements de protection électrosensibles (ESPE) conçus spécialement pour détecter des personnes, comme partie d'un système relatif à la sécurité, utilisant des dispositifs protecteurs optoélectroniques actifs (AOPD) pour la fonction de détection. Une attention particulière est portée sur les caractéristiques assurant qu'une performance relative à la sécurité appropriée est atteinte. Un ESPE peut comporter des fonctions de sécurité facultatives. Les exigences pour ces fonctions sont données à l'Annexe A de l'IEC 61496 1:2020 et du présent document.
Le présent document ne spécifie ni les dimensions et configurations de la zone de détection, ni sa disposition par rapport aux parties dangereuses dans une application particulière, ni ce qui constitue un état dangereux pour toute machine donnée. Il se limite au fonctionnement de l'ESPE et à son interface avec la machine.
Le présent document ne traite pas des AOPD qui utilisent des longueurs d'ondes hors de la plage de 400 nm à 1 500 nm.
Le présent document peut être pertinent pour des applications autres que la protection des personnes, par exemple la protection des machines ou des produits contre des dommages mécaniques. Dans ces applications, des exigences complémentaires peuvent être nécessaires, par exemple lorsque les matériaux qui doivent être reconnus par le dispositif de détection ont des caractéristiques différentes de celles des personnes.
Le présent document ne traite pas des exigences CEM (compatibilité électromagnétique) relatives aux émissions électromagnétiques.
L'IEC 61496-2:2020 annule et remplace la troisième édition parue en 2013. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) Les exigences et procédures d’essai de la Partie 2 qui se sont révélées être communes à tous les ESPE ont été déplacées vers la Partie 1. Les procédures d’essai qui dépendent de la technologie de détection restent dans la Partie 2.

General Information

Status
Published
Publication Date
14-Jul-2020
Current Stage
PPUB - Publication issued
Completion Date
15-Jul-2020
Ref Project

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IEC 61496-2
Edition 4.0 2020-07
INTERNATIONAL
STANDARD
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 2: Particular requirements for equipment using active opto-electronic
protective devices (AOPDs)
IEC 61496-2:2020-07(en)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 61496-2
Edition 4.0 2020-07
INTERNATIONAL
STANDARD
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 2: Particular requirements for equipment using active opto-electronic
protective devices (AOPDs)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.110; 29.260.99 ISBN 978-2-8322-8452-0

Warning! Make sure that you obtained this publication from an authorized distributor.

® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 3 ----------------------
– 2 – IEC 61496-2:2020 © IEC 2020
CONTENTS

FOREWORD ........................................................................................................................... 4

INTRODUCTION ..................................................................................................................... 6

1 Scope .............................................................................................................................. 7

2 Normative references ...................................................................................................... 7

3 Terms and definitions ...................................................................................................... 8

4 Functional, design and environmental requirements ........................................................ 9

5 Testing .......................................................................................................................... 14

6 Marking for identification and safe use ........................................................................... 40

7 Accompanying documents ............................................................................................. 41

Annex A (normative) Optional functions of the ESPE ........................................................... 42

Annex AA (informative) Type 2 AOPD periodic test configurations ....................................... 46

Figure 1 – Limit area for the protection against the risk of beam bypass ............................... 12

Figure 2 – Limit of vertical and horizontal misalignment ........................................................ 13

Figure 3 – Test piece at 45° .................................................................................................. 18

Figure 4 – Test piece at 90° .................................................................................................. 18

Figure 5 – Verifying sensing function by moving the test piece (TP) through the

detection zone near the emitter, near the receiver/retro-reflector target and at the

midpoint ................................................................................................................................ 19

Figure 6 – Limit values for the effective aperture angle (EAA) ............................................... 21

Figure 7 – Determination of the minimum detection capability ............................................... 22

Figure 8 – Measuring method for EAA (direction) .................................................................. 23

Figure 9 – Prism test to measure EAA of each beam ............................................................ 25

Figure 10 – EAA test using prism .......................................................................................... 26

Figure 11 – Example of optical subsystem ............................................................................ 27

Figure 12 – Example of SMD LED Model .............................................................................. 28

Figure 13 – Example of intensity distribution of emitting element .......................................... 28

Figure 14 – Example of emitter model with beams internally blocked by aperture stop .......... 29

Figure 15 – Example of receiving unit with off axis beam portion reflected internally on

mechanical elements ............................................................................................................ 29

Figure 16 – Example of test piece inside model of optical subsystem with passing

radiation on the receiver ....................................................................................................... 30

Figure 17 – Example of emitting unit adjusted at the limit ...................................................... 31

Figure 18 – Extraneous reflection test with mirror outside of limit area .................................. 32

Figure 19 – AOPD misalignment test .................................................................................... 34

Figure 20 – Light interference test – Direct method ............................................................... 36

Figure 21 – Light interference test – Test set-up with incandescent light source ................... 37

Figure 22 – Light interference test – Test set-up with fluorescent light source ....................... 38

Figure 23 – Light interference test – Test set-up with flashing beaconlight source ................ 39

Figure AA.1 – Single beam sensing device ........................................................................... 46

Figure AA.2 – Series connection of single beam sensing devices ......................................... 46

Figure AA.3 – Assembly of multiple beams tested individually............................................... 46

Figure AA.4 – Example of type 2 AOPD with internal test ...................................................... 47

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IEC 61496-2:2020 © IEC 2020 – 3 –

Table 1 – Correspondences of requirements/testing and AOPD designs ............................... 15

Table 2 – Maximum permissible angle of misalignment (in degrees) for a type 2 ESPE

depending on the dimensions of the light curtain ................................................................... 32

Table 3 – Maximum permissible angle of misalignment (in degrees) for a type 3 ESPE

depending on the dimensions of the light curtain ................................................................... 33

Table 4 – Maximum permissible angle of misalignment (in degrees) for a type 4 ESPE

depending on the dimensions of the light curtain ................................................................... 33

---------------------- Page: 5 ----------------------
– 4 – IEC 61496-2:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –
Part 2: Particular requirements for equipment using
active opto-electronic protective devices (AOPDs)
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

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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 61496-2 has been prepared by IEC technical committee 44: Safety

of machinery – Electrotechnical aspects, in collaboration with CENELEC technical committee

44X: Safety of machinery – Electrotechnical aspects.

This fourth edition cancels and replaces the third edition published in 2013. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) Requirements and test procedures in Part 2 that were found to be common to all ESPEs

have been moved to Part 1. Test procedures that are dependent on the sensing
technology remain in Part 2.
---------------------- Page: 6 ----------------------
IEC 61496-2:2020 © IEC 2020 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
44/875/FDIS 44/878/RVD

Full information on the voting for the approval of this International Standard can be found in

the report on voting indicated in the above table.

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

This standard has the status of a product family standard and can be used as a normative

reference in a dedicated product standard for the safety of machinery.
This standard is to be used in conjunction with IEC 61496-1:2020.
This part supplements or modifies the corresponding clauses in IEC 61496-1:2020.

Where a particular clause or subclause of IEC 61496-1:2020 is not mentioned in this Part 2,

that clause or subclause applies as far as is reasonable. Where this part states "Addition",

"Modification" or "Replacement", the relevant text of IEC 61496-1:2020 is adapted

accordingly.

Clauses and subclauses which are additional to those of Part 1 are numbered sequentially,

following on the last available number in Part 1. Terminological entries (in Clause 3) which are

additional to those in Part 1 are numbered starting from 3.201. Additional annexes are

lettered from AA onwards.

A list of all parts in the IEC 61496 series, published under the general title Safety of

machinery – Electro-sensitive protective equipment, can be found on the IEC website.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
---------------------- Page: 7 ----------------------
– 6 – IEC 61496-2:2020 © IEC 2020
INTRODUCTION

Electro-sensitive protective equipment (ESPE) is applied to machinery that presents a risk of

personal injury. It provides protection by causing the machine to revert to a safe condition

before a person can be placed in a hazardous situation.

This document provides particular requirements for the design, construction and testing of

electro-sensitive protective equipment (ESPE) for the safeguarding of machinery, employing

active opto-electronic protective devices (AOPDs) for the sensing function.

Each type of machine presents its own particular hazards, and it is not the purpose of this

document to recommend the manner of application of the ESPE to any particular machine.

The application of the ESPE should be a matter for agreement between the equipment

supplier, the machine user and the enforcing authority; in this context, attention is drawn to

the relevant guidance established internationally, for example, ISO 12100.

Due to the complexity of the technology of ESPEs, there are many issues that are highly

dependent on analysis and expertise in specific test and measurement techniques. In order to

provide a high level of confidence, independent review by relevant expertise is recommended.

---------------------- Page: 8 ----------------------
IEC 61496-2:2020 © IEC 2020 – 7 –
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –
Part 2: Particular requirements for equipment using
active opto-electronic protective devices (AOPDs)
1 Scope
This clause of Part 1 is replaced by the following:

This part of IEC 61496 specifies requirements for the design, construction and testing of

electro-sensitive protective equipment (ESPE) designed specifically to detect persons as part

of a safety-related system, employing active opto-electronic protective devices (AOPDs) for

the sensing function. Special attention is directed to features which ensure that an

appropriate safety-related performance is achieved. An ESPE can include optional safety-

related functions, the requirements for which are given in Annex A of IEC 61496-1:2020 and

of this document.

This document does not specify the dimensions or configurations of the detection zone and its

disposition in relation to hazardous parts for any particular application, nor what constitutes a

hazardous state of any machine. It is restricted to the functioning of the ESPE and how it

interfaces with the machine.

Excluded from this document are AOPDs employing radiation at wavelengths outside the

range 400 nm to 1 500 nm.

This document can be relevant to applications other than those for the protection of persons,

for example, the protection of machinery or products from mechanical damage. In those

applications, additional requirements can be necessary, for example, when the materials that

are to be recognized by the sensing function have different properties from those of persons.

This document does not deal with electromagnetic compatibility (EMC) emission
requirements.
2 Normative references
This clause of Part 1 is applicable except as follows:
Addition:

IEC 60825-1, Safety of laser products – Part 1: Equipment classification and requirements

IEC 61496-1:2020, Safety of machinery – Electro-sensitive protective equipment – Part 1:

General requirements and tests
IEC 62471, Photobiological safety of lamps and lamp systems

ISO 13855, Safety of machinery – Positioning of safeguards with respect to the approach

speeds of parts of the human body
ISO 20471, High-visibility clothing – Test methods and requirements
___________
To be published.
---------------------- Page: 9 ----------------------
– 8 – IEC 61496-2:2020 © IEC 2020
3 Terms and definitions
This clause of Part 1 is applicable except as follows:
Addition:
3.201
active opto-electronic protective device
AOPD

device whose sensing function is performed by opto-electronic emitting and receiving

elements detecting the interruption of optical radiations generated, within the device, by an

opaque object present in the specified detection zone (or for a light beam device, on the axis

of the light beam)
Note 1 to entry: This note applies to the French language only.
3.202
beam centre-line

optical path joining the optical centre of an emitting element to the optical centre of the

corresponding receiving element that is intended to respond to light from that emitting

element during normal operation

Note 1 to entry: The optical axis of a light beam is not always on the beam centre-line.

Note 2 to entry: Physical displacement of the beam centre-line may occur as a consequence of normal operation

(for example, by the use of a motor-driven mirror).

Note 3 to entry: For an AOPD that operates on a retro-reflective technique, the optical path is defined by the

retro-reflector target together with the emitting and receiving elements.
3.203
effective aperture angle
EAA

maximum angle of deviation from the optical alignment of the emitting element(s) and the

receiving element(s) within which the AOPD continues in normal operation
3.204
light beam device

AOPD comprising one or more emitting element(s) and corresponding receiving element(s),

where a detection zone is not specified by the supplier
3.205
light curtain

AOPD comprising an integrated assembly of one or more emitting element(s) and one or more

receiving element(s) forming a detection zone with a detection capability specified by the

supplier

Note 1 to entry: A light curtain with a large detection capability is sometimes referred to as a light grid.

3.206
test piece
opaque cylindrical element used to verify the detection capability of the AOPD
3.207
geometrically restricted optical design
GROD
AOPD using an optic design where

– the effective aperture angle (EAA) of each emitting and each receiving element does not

exceed the values given in Figure 6 and
– the axes of the optical beams are parallel and
---------------------- Page: 10 ----------------------
IEC 61496-2:2020 © IEC 2020 – 9 –
– side lobes are minimized and
– the spacing between beam centre-lines is uniform and

– the value of detection capability is based on the complete obscuration of at least one

beam for any and all positions of the test piece within the detection zone (see Figure 7).

Replacement:
3.3
detection capability
dimension representing the diameter of the test piece which:

– for a light curtain, will actuate the sensing device when placed in the detection zone;

– for a single light beam device, will actuate the sensing device when placed in the beam

centre-line;

– for a multiple light beam device, will actuate the sensing device when placed in any beam

centre-line

Note 1 to entry: The term "detection capability" can also be used to mean the ability to detect a test piece of the

specified diameter.
4 Functional, design and environmental requirements
This clause of Part 1 is applicable except as follows:
4.1 Functional requirements
4.1.2 Sensing function
Replacement:
4.1.2.1 General requirements

The sensing function shall be effective over the detection zone specified by the supplier. No

adjustment of the detection zone, detection capability or blanking function shall be possible

without the use of a key, keyword or tool.

The sensing device of a light curtain shall be actuated and the OSSD(s) shall go to and

remain in the OFF-state when a test piece in accordance with 4.2.13 is present anywhere

within the detection zone either static (at any angle) or moving (with the axis of the cylinder

normal to the plane of the detection zone), at any speed between 0 m/s and 1,6 m/s.

The sensing device of a light beam device shall be actuated and the OSSD(s) shall go to and

remain in the OFF-state when a test piece in accordance with 4.2.13 is present in the beam

centre-line, at any point throughout the operating distance, with the axis of the cylinder normal

to the axis of the beam.

Where the supplier states that an AOPD can be used to detect objects moving at speeds

greater than those specified above, the above requirements shall be met at any speed up to

and including the stated maximum speed(s).
---------------------- Page: 11 ----------------------
– 10 – IEC 61496-2:2020 © IEC 2020

4.1.2.2 Additional requirements for AOPDs using retro-reflective techniques and for

AOPDs using mixed emitters and receivers in the same assembly
4.1.2.2.1 General

AOPDs using retro-reflective techniques where the light beam traverses the detection zone

more than once (over the same path) and AOPDs using mixed emitters and receivers in the

same assembly shall not fail to danger if a reflective object (for example, reflective clothes) is

placed at any position in the detection zone.

NOTE The use of mirrors to return the light beam is not considered to be a retro-reflective technique.

4.1.2.2.2 Sensing function

The OSSD(s) shall go to the OFF-state when a reflective object of a size equal to, or greater

than, the diameter and length of the test piece (see 4.2.13) is placed in the detection zone at

any position as specified in 5.2.1.4.

For a type 3 AOPD or a type 4 AOPD, under normal operating conditions, the OSSD(s) shall

go to the OFF-state when a reflective object, as specified in 5.2.1.4, is placed as close as

practicable in front of the sensing surface of the emitting/receiving elements.
4.1.3 Types of ESPE
Replacement:

In this document, only type 2, type 3 and type 4 ESPEs are considered. The types differ in

their performance in the presence of faults and under influences from environmental

conditions. In IEC 61496-1:2020, the effects of electrical and electromechanical faults are

considered (such faults are listed in Annex B of IEC 61496-1:2020).

NOTE The machine supplier and/or the user will determine which type is required for a particular application.

For a type 2 ESPE, in normal operation the output circuit of at least one output signal

switching device shall go to the OFF-state when the sensing function is actuated, or when

power is removed from the ESPE.
A type 2 ESPE shall fulfil the fault detection requirements of 4.2.2.3.
A type 3 ESPE shall fulfil the fault detection requirements of 4.2.2.4.
A type 4 ESPE shall fulfil the fault detection requirements of 4.2.2.5.

For a type 3 or a type 4 ESPE, in normal operation the output circuit of at least two output

signal switching devices shall go to the OFF-state when the sensing function is actuated, or

when power is removed from the ESPE.

When a single safety-related data interface is used to perform the functions of the OSSD(s),

the data interface and associated safety-related communication interface shall meet the

requirements of 4.2.4.4 of IEC 61496-1:2020. In this case, a single safety-related data

interface can substitute for two OSSDs in a type 3 ESPE or a type 4 ESPE.
---------------------- Page: 12 ----------------------
IEC 61496-2:2020 © IEC 2020 – 11 –
4.2 Design requirements
4.2.2 Fault detection requirements
4.2.2.3 Particular requirements for a type 2 ESPE
Addition:

The periodic test shall verify that each light beam operates in the manner specified by the

supplier.

Different configurations are considered that differ in the way the testing of the safety related

performance is carried out.

Annex AA, Figure AA.1, Figure AA.2 and Figure AA.3 are examples of type 2 AOPDs where

the periodic test is externally initiated and the results are externally evaluated. Annex AA,

Figure AA.4 is an example of a type 2 AOPD where the periodic test is automatically initiated

and evaluated internally.
Replacement:
4.2.12 Integrity of the AOPD detection capability

The design of the AOPD shall be such that the AOPD detection capability does not change

from the value stated by the supplier when the AOPD is operated under any and all

combinations of the following:
– any condition within the specification of the supplier;
– the environmental conditions specified in 4.3;
– at the limits of alignment and/or adjustment;
– over the entire detection zone.

If a single fault (as specified in Annex B of IEC 61496-1:2020), which under normal operating

conditions (see 5.1.2.1) would not result in a loss of AOPD detection capability but, when

occurring with a combination of the conditions specified above, would result in such a loss,

that fault together with that combination of conditions shall be considered as a single fault,

and the AOPD shall respond to such a single fault as required in 4.2.2.
The AOPD shall be designed and constructed to:

a) limit the possibility of failure to danger resulting from extraneous reflections (for operating

range up to 3 m, see Figure 1);
b) limit the misalignment at which normal operation is possible.
For an operating range of 3 m the limits of Figure 2 shall be met;

c) limit the possibility of malfunction during exposure to extraneous light in the range of

400 nm to 1 500 nm.
---------------------- Page: 13 ----------------------
– 12 – IEC 61496-2:2020 © IEC 2020
For type 4: d = 131 mm, L = 250 mm to 3 000 mm
For type 3: d = 184 mm, L = 375 mm to 3 000 mm
For type 2: d = 262 mm, L = 500 mm to 3 000 mm

NOTE In this figure, extraneous reflections from surfaces outside the shaded area will not cause a failure to

danger. For short ranges (250 mm for type 4, 375 mm for type 3 and 500 mm for type 2), the angle of 35° is a limit

selected by the working group based on known designs of AOPDs.
Figure 1 – Limit area for the protection against the risk of beam bypass

If the AOPD is intended to provide protection when mounted very close to a reflective surface

(i.e. inside the shaded area of Figure 1), the AOPD shall be designed in such a manner that

no optical bypassing can occur on the reflective surfaces. For such a device, an EAA much

less than 2,5° (for example, less than 0,1°) can be necessary. In this case, Figure 1 does not

apply and the limits of protection against optical bypassing shall be as specified by the

manufacturer.
---------------------- Page: 14 ----------------------
IEC 61496-2:2020 © IEC 2020 – 13 –
For type 4: 2d = 262 mm, L = 3 000 mm
For type 3: 2d = 368 mm, L = 3
...

IEC 61496-2
Edition 4.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 2: Particular requirements for equipment using active opto-electronic
protective devices (AOPDs)
Sécurité des machines – Équipements de protection électrosensibles –
Partie 2: Exigences particulières pour un équipement utilisant des dispositifs
protecteurs optoélectroniques actifs (AOPD)
IEC 61496-2:2020-07(en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
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---------------------- Page: 2 ----------------------
IEC 61496-2
Edition 4.0 2020-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 2: Particular requirements for equipment using active opto-electronic
protective devices (AOPDs)
Sécurité des machines – Équipements de protection électrosensibles –
Partie 2: Exigences particulières pour un équipement utilisant des dispositifs
protecteurs optoélectroniques actifs (AOPD)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.110; 29.260.99 ISBN 978-2-8322-9447-5

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 61496-2:2020 © IEC 2020
CONTENTS

FOREWORD ........................................................................................................................... 4

INTRODUCTION ..................................................................................................................... 6

1 Scope .............................................................................................................................. 7

2 Normative references ...................................................................................................... 7

3 Terms and definitions ...................................................................................................... 8

4 Functional, design and environmental requirements ........................................................ 9

5 Testing .......................................................................................................................... 14

6 Marking for identification and safe use ........................................................................... 40

7 Accompanying documents ............................................................................................. 41

Annex A (normative) Optional functions of the ESPE ........................................................... 42

Annex AA (informative) Type 2 AOPD periodic test configurations ....................................... 46

Figure 1 – Limit area for the protection against the risk of beam bypass ............................... 12

Figure 2 – Limit of vertical and horizontal misalignment ........................................................ 13

Figure 3 – Test piece at 45° .................................................................................................. 18

Figure 4 – Test piece at 90° .................................................................................................. 18

Figure 5 – Verifying sensing function by moving the test piece (TP) through the

detection zone near the emitter, near the receiver/retro-reflector target and at the

midpoint ................................................................................................................................ 19

Figure 6 – Limit values for the effective aperture angle (EAA) ............................................... 21

Figure 7 – Determination of the minimum detection capability ............................................... 22

Figure 8 – Measuring method for EAA (direction) .................................................................. 23

Figure 9 – Prism test to measure EAA of each beam ............................................................ 25

Figure 10 – EAA test using prism .......................................................................................... 26

Figure 11 – Example of optical subsystem ............................................................................ 27

Figure 12 – Example of SMD LED Model .............................................................................. 28

Figure 13 – Example of intensity distribution of emitting element .......................................... 28

Figure 14 – Example of emitter model with beams internally blocked by aperture stop .......... 29

Figure 15 – Example of receiving unit with off axis beam portion reflected internally on

mechanical elements ............................................................................................................ 29

Figure 16 – Example of test piece inside model of optical subsystem with passing

radiation on the receiver ....................................................................................................... 30

Figure 17 – Example of emitting unit adjusted at the limit ...................................................... 31

Figure 18 – Extraneous reflection test with mirror outside of limit area .................................. 32

Figure 19 – AOPD misalignment test .................................................................................... 34

Figure 20 – Light interference test – Direct method ............................................................... 36

Figure 21 – Light interference test – Test set-up with incandescent light source ................... 37

Figure 22 – Light interference test – Test set-up with fluorescent light source ....................... 38

Figure 23 – Light interference test – Test set-up with flashing beaconlight source ................ 39

Figure AA.1 – Single beam sensing device ........................................................................... 46

Figure AA.2 – Series connection of single beam sensing devices ......................................... 46

Figure AA.3 – Assembly of multiple beams tested individually............................................... 46

Figure AA.4 – Example of type 2 AOPD with internal test ...................................................... 47

---------------------- Page: 4 ----------------------
IEC 61496-2:2020 © IEC 2020 – 3 –

Table 1 – Correspondences of requirements/testing and AOPD designs ............................... 15

Table 2 – Maximum permissible angle of misalignment (in degrees) for a type 2 ESPE

depending on the dimensions of the light curtain ................................................................... 32

Table 3 – Maximum permissible angle of misalignment (in degrees) for a type 3 ESPE

depending on the dimensions of the light curtain ................................................................... 33

Table 4 – Maximum permissible angle of misalignment (in degrees) for a type 4 ESPE

depending on the dimensions of the light curtain ................................................................... 33

---------------------- Page: 5 ----------------------
– 4 – IEC 61496-2:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –
Part 2: Particular requirements for equipment using
active opto-electronic protective devices (AOPDs)
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,

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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

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interested IEC National Committees.

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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

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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 61496-2 has been prepared by IEC technical committee 44: Safety

of machinery – Electrotechnical aspects, in collaboration with CENELEC technical committee

44X: Safety of machinery – Electrotechnical aspects.

This fourth edition cancels and replaces the third edition published in 2013. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) Requirements and test procedures in Part 2 that were found to be common to all ESPEs

have been moved to Part 1. Test procedures that are dependent on the sensing
technology remain in Part 2.
---------------------- Page: 6 ----------------------
IEC 61496-2:2020 © IEC 2020 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
44/875/FDIS 44/878/RVD

Full information on the voting for the approval of this International Standard can be found in

the report on voting indicated in the above table.

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

This standard has the status of a product family standard and can be used as a normative

reference in a dedicated product standard for the safety of machinery.
This standard is to be used in conjunction with IEC 61496-1:2020.
This part supplements or modifies the corresponding clauses in IEC 61496-1:2020.

Where a particular clause or subclause of IEC 61496-1:2020 is not mentioned in this Part 2,

that clause or subclause applies as far as is reasonable. Where this part states "Addition",

"Modification" or "Replacement", the relevant text of IEC 61496-1:2020 is adapted

accordingly.

Clauses and subclauses which are additional to those of Part 1 are numbered sequentially,

following on the last available number in Part 1. Terminological entries (in Clause 3) which are

additional to those in Part 1 are numbered starting from 3.201. Additional annexes are

lettered from AA onwards.

A list of all parts in the IEC 61496 series, published under the general title Safety of

machinery – Electro-sensitive protective equipment, can be found on the IEC website.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
---------------------- Page: 7 ----------------------
– 6 – IEC 61496-2:2020 © IEC 2020
INTRODUCTION

Electro-sensitive protective equipment (ESPE) is applied to machinery that presents a risk of

personal injury. It provides protection by causing the machine to revert to a safe condition

before a person can be placed in a hazardous situation.

This document provides particular requirements for the design, construction and testing of

electro-sensitive protective equipment (ESPE) for the safeguarding of machinery, employing

active opto-electronic protective devices (AOPDs) for the sensing function.

Each type of machine presents its own particular hazards, and it is not the purpose of this

document to recommend the manner of application of the ESPE to any particular machine.

The application of the ESPE should be a matter for agreement between the equipment

supplier, the machine user and the enforcing authority; in this context, attention is drawn to

the relevant guidance established internationally, for example, ISO 12100.

Due to the complexity of the technology of ESPEs, there are many issues that are highly

dependent on analysis and expertise in specific test and measurement techniques. In order to

provide a high level of confidence, independent review by relevant expertise is recommended.

---------------------- Page: 8 ----------------------
IEC 61496-2:2020 © IEC 2020 – 7 –
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –
Part 2: Particular requirements for equipment using
active opto-electronic protective devices (AOPDs)
1 Scope
This clause of Part 1 is replaced by the following:

This part of IEC 61496 specifies requirements for the design, construction and testing of

electro-sensitive protective equipment (ESPE) designed specifically to detect persons as part

of a safety-related system, employing active opto-electronic protective devices (AOPDs) for

the sensing function. Special attention is directed to features which ensure that an

appropriate safety-related performance is achieved. An ESPE can include optional safety-

related functions, the requirements for which are given in Annex A of IEC 61496-1:2020 and

of this document.

This document does not specify the dimensions or configurations of the detection zone and its

disposition in relation to hazardous parts for any particular application, nor what constitutes a

hazardous state of any machine. It is restricted to the functioning of the ESPE and how it

interfaces with the machine.

Excluded from this document are AOPDs employing radiation at wavelengths outside the

range 400 nm to 1 500 nm.

This document can be relevant to applications other than those for the protection of persons,

for example, the protection of machinery or products from mechanical damage. In those

applications, additional requirements can be necessary, for example, when the materials that

are to be recognized by the sensing function have different properties from those of persons.

This document does not deal with electromagnetic compatibility (EMC) emission
requirements.
2 Normative references
This clause of Part 1 is applicable except as follows:
Addition:

IEC 60825-1, Safety of laser products – Part 1: Equipment classification and requirements

IEC 61496-1:2020, Safety of machinery – Electro-sensitive protective equipment – Part 1:

General requirements and tests
IEC 62471, Photobiological safety of lamps and lamp systems

ISO 13855, Safety of machinery – Positioning of safeguards with respect to the approach

speeds of parts of the human body
ISO 20471, High-visibility clothing – Test methods and requirements
___________
To be published.
---------------------- Page: 9 ----------------------
– 8 – IEC 61496-2:2020 © IEC 2020
3 Terms and definitions
This clause of Part 1 is applicable except as follows:
Addition:
3.201
active opto-electronic protective device
AOPD

device whose sensing function is performed by opto-electronic emitting and receiving

elements detecting the interruption of optical radiations generated, within the device, by an

opaque object present in the specified detection zone (or for a light beam device, on the axis

of the light beam)
Note 1 to entry: This note applies to the French language only.
3.202
beam centre-line

optical path joining the optical centre of an emitting element to the optical centre of the

corresponding receiving element that is intended to respond to light from that emitting

element during normal operation

Note 1 to entry: The optical axis of a light beam is not always on the beam centre-line.

Note 2 to entry: Physical displacement of the beam centre-line may occur as a consequence of normal operation

(for example, by the use of a motor-driven mirror).

Note 3 to entry: For an AOPD that operates on a retro-reflective technique, the optical path is defined by the

retro-reflector target together with the emitting and receiving elements.
3.203
effective aperture angle
EAA

maximum angle of deviation from the optical alignment of the emitting element(s) and the

receiving element(s) within which the AOPD continues in normal operation
3.204
light beam device

AOPD comprising one or more emitting element(s) and corresponding receiving element(s),

where a detection zone is not specified by the supplier
3.205
light curtain

AOPD comprising an integrated assembly of one or more emitting element(s) and one or more

receiving element(s) forming a detection zone with a detection capability specified by the

supplier

Note 1 to entry: A light curtain with a large detection capability is sometimes referred to as a light grid.

3.206
test piece
opaque cylindrical element used to verify the detection capability of the AOPD
3.207
geometrically restricted optical design
GROD
AOPD using an optic design where

– the effective aperture angle (EAA) of each emitting and each receiving element does not

exceed the values given in Figure 6 and
– the axes of the optical beams are parallel and
---------------------- Page: 10 ----------------------
IEC 61496-2:2020 © IEC 2020 – 9 –
– side lobes are minimized and
– the spacing between beam centre-lines is uniform and

– the value of detection capability is based on the complete obscuration of at least one

beam for any and all positions of the test piece within the detection zone (see Figure 7).

Replacement:
3.3
detection capability
dimension representing the diameter of the test piece which:

– for a light curtain, will actuate the sensing device when placed in the detection zone;

– for a single light beam device, will actuate the sensing device when placed in the beam

centre-line;

– for a multiple light beam device, will actuate the sensing device when placed in any beam

centre-line

Note 1 to entry: The term "detection capability" can also be used to mean the ability to detect a test piece of the

specified diameter.
4 Functional, design and environmental requirements
This clause of Part 1 is applicable except as follows:
4.1 Functional requirements
4.1.2 Sensing function
Replacement:
4.1.2.1 General requirements

The sensing function shall be effective over the detection zone specified by the supplier. No

adjustment of the detection zone, detection capability or blanking function shall be possible

without the use of a key, keyword or tool.

The sensing device of a light curtain shall be actuated and the OSSD(s) shall go to and

remain in the OFF-state when a test piece in accordance with 4.2.13 is present anywhere

within the detection zone either static (at any angle) or moving (with the axis of the cylinder

normal to the plane of the detection zone), at any speed between 0 m/s and 1,6 m/s.

The sensing device of a light beam device shall be actuated and the OSSD(s) shall go to and

remain in the OFF-state when a test piece in accordance with 4.2.13 is present in the beam

centre-line, at any point throughout the operating distance, with the axis of the cylinder normal

to the axis of the beam.

Where the supplier states that an AOPD can be used to detect objects moving at speeds

greater than those specified above, the above requirements shall be met at any speed up to

and including the stated maximum speed(s).
---------------------- Page: 11 ----------------------
– 10 – IEC 61496-2:2020 © IEC 2020

4.1.2.2 Additional requirements for AOPDs using retro-reflective techniques and for

AOPDs using mixed emitters and receivers in the same assembly
4.1.2.2.1 General

AOPDs using retro-reflective techniques where the light beam traverses the detection zone

more than once (over the same path) and AOPDs using mixed emitters and receivers in the

same assembly shall not fail to danger if a reflective object (for example, reflective clothes) is

placed at any position in the detection zone.

NOTE The use of mirrors to return the light beam is not considered to be a retro-reflective technique.

4.1.2.2.2 Sensing function

The OSSD(s) shall go to the OFF-state when a reflective object of a size equal to, or greater

than, the diameter and length of the test piece (see 4.2.13) is placed in the detection zone at

any position as specified in 5.2.1.4.

For a type 3 AOPD or a type 4 AOPD, under normal operating conditions, the OSSD(s) shall

go to the OFF-state when a reflective object, as specified in 5.2.1.4, is placed as close as

practicable in front of the sensing surface of the emitting/receiving elements.
4.1.3 Types of ESPE
Replacement:

In this document, only type 2, type 3 and type 4 ESPEs are considered. The types differ in

their performance in the presence of faults and under influences from environmental

conditions. In IEC 61496-1:2020, the effects of electrical and electromechanical faults are

considered (such faults are listed in Annex B of IEC 61496-1:2020).

NOTE The machine supplier and/or the user will determine which type is required for a particular application.

For a type 2 ESPE, in normal operation the output circuit of at least one output signal

switching device shall go to the OFF-state when the sensing function is actuated, or when

power is removed from the ESPE.
A type 2 ESPE shall fulfil the fault detection requirements of 4.2.2.3.
A type 3 ESPE shall fulfil the fault detection requirements of 4.2.2.4.
A type 4 ESPE shall fulfil the fault detection requirements of 4.2.2.5.

For a type 3 or a type 4 ESPE, in normal operation the output circuit of at least two output

signal switching devices shall go to the OFF-state when the sensing function is actuated, or

when power is removed from the ESPE.

When a single safety-related data interface is used to perform the functions of the OSSD(s),

the data interface and associated safety-related communication interface shall meet the

requirements of 4.2.4.4 of IEC 61496-1:2020. In this case, a single safety-related data

interface can substitute for two OSSDs in a type 3 ESPE or a type 4 ESPE.
---------------------- Page: 12 ----------------------
IEC 61496-2:2020 © IEC 2020 – 11 –
4.2 Design requirements
4.2.2 Fault detection requirements
4.2.2.3 Particular requirements for a type 2 ESPE
Addition:

The periodic test shall verify that each light beam operates in the manner specified by the

supplier.

Different configurations are considered that differ in the way the testing of the safety related

performance is carried out.
Annex AA, Figure AA.1, Fi
...

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