IEC TS 61496-4-2:2022

IEC TS 61496-4-2 ®
Edition 2.0 2022-09
REDLINE VERSION
TECHNICAL
SPECIFICATION
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 4-2: Particular requirements for equipment using vision based protective
devices (VBPD) – Additional requirements when using reference pattern
techniques (VBPDPP)
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IEC TS 61496-4-2 ®
Edition 2.0 2022-09
REDLINE VERSION
TECHNICAL
SPECIFICATION
colour
inside
Safety of machinery – Electro-sensitive protective equipment –
Part 4-2: Particular requirements for equipment using vision based protective
devices (VBPD) – Additional requirements when using reference pattern
techniques (VBPDPP)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.110; 29.260.99 ISBN 978-2-8322-5727-2
– 2 – IEC TS 61496-4-2:2022 RLV © IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 2
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 Functional, design and environmental requirements . 10
5 Testing . 20
6 Marking for identification and for safe use . 34
7 Accompanying documents . 34
Annex A (normative) Optional functions of the ESPE . 35
Annex B (normative) Catalogue of single faults affecting the electrical equipment of
the ESPE, to be applied as specified in 5.3 . 38
Annex AA (informative) The positioning of VBPD in respect of parts of the human body . 39
Bibliography . 46

Figure 1 – Image planes in VBPDPP . 10
Figure 2 – Side view of VBPDPP using a passive reference pattern . 12
Figure 3 – Light intensity measurement setup for indirect light tests . 30
Figure 4 – Light intensity measurement setup for direct light tests . 32
Figure AA.1 – Minimum distance S – Example 1 . 42
Figure AA.2 – Overall minimum distance S without tolerance zone – Example 1 . 42
o
Figure AA.3 – Overall minimum distance S including tolerance zone – Example 1 . 43
o
Figure AA.4 – Minimum distance S – Example 2 . 44
Figure AA.5 – Overall minimum distance S without tolerance zone – Example 2 . 45
o
Figure AA.6 – Overall minimum distance S including tolerance zone – Example 2 . 45
o
Table 1 421 – Verification of detection capability requirements (see also 4.2.12) . 21
Table 2 422 – Overview of light interference tests . 25

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –

Part 4-2: Particular requirements for equipment
using vision based protective devices (VBPD) –
Additional requirements when using reference
pattern techniques (VBPDPP)
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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This redline version of the official IEC Standard allows the user to identify the changes made to
the previous edition IEC TS 61496-4-2:2014. A vertical bar appears in the margin wherever a
change has been made. Additions are in green text, deletions are in strikethrough red text.

– 4 – IEC TS 61496-4-2:2022 RLV © IEC 2022
IEC TS 61496-4-2 has been prepared by IEC technical committee TC 44: Safety of machinery
– Electrotechnical aspects. It is a Technical Specification.
This second edition cancels and replaces the first edition published in 2014. This edition
constitutes a technical revision.
This edition includes the following technical changes with respect to the previous edition:
a) Some requirement clauses and test procedures have been adapted or removed because
they have been consolidated in IEC 61496-1:2020 (e.g. 5.4.6.2 of IEC 61496-1:2020 Light
sources or Clause A.9)
The text of this document is based on the following documents:
Draft Report on voting
44/933/DTS 44/955A/RVDTS
Full information on the voting for the approval of this document can be found in the report on
voting indicated in the above table.
The language used for the development of this document is English.
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 http://www.iec.ch/standardsdev/publications.
This document is to be used in conjunction with IEC 61496-1:2020.
This document supplements or modifies the corresponding clauses in IEC 61496-1:2020 to
specify particular requirements for the design, construction and testing of electro-sensitive
protective equipment (ESPE) for the safeguarding of machinery, employing vision based
protective devices (VBPD) using reference pattern techniques (VBPDPP) for the sensing
function.
Where a particular clause or subclause of IEC 61496-1:2020 is not mentioned in this document,
that clause or subclause applies as far as is reasonable. Where this document 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 IEC 61496-1:2020 are numbered
sequentially, following on the last available number in IEC 61496-1:2020. Terminological entries
(in Clause 3) which are additional to those in IEC 61496-1:2020 are numbered starting from
3.4201. Additional annexes are lettered from AA onwards and additional tables are numbered
with prefix 42
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 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.

– 6 – IEC TS 61496-4-2:2022 RLV © IEC 2022
INTRODUCTION
An electro-sensitive protective equipment (ESPE) is applied to machinery presenting 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.
The working group responsible for drafting this document was concerned that, due to the
complexity of the technology, 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 required recommended. They
considered that if this high level of confidence could not be established these devices would
not be suitable for use in safety related applications.

SAFETY OF MACHINERY –
ELECTRO-SENSITIVE PROTECTIVE EQUIPMENT –

Part 4-2: Particular requirements for equipment
using vision based protective devices (VBPD) –
Additional requirements when using reference
patter
...