Home and Building Electronic Systems (HBES) -- Part 2-3: System overview - General functional safety requirements for products intended to be integrated in HBES

This European Standard sets the requirements for functional safety for HBES products and systems, a multi-application bus system where the functions are decentralised, distributed and linked through a common communication process. The requirements may also apply to the distributed functions of any equipment connected in a home or building control system if no specific functional safety standard exist for this equipment or system.  The functional safety requirements of this European Standard apply together with the relevant product standard for the device if any. This European Standard is used as a product family standard. It is not intended to be used as a stand-alone standard. This European Standard does not provide functional safety requirements for safety-related systems.

Elektrische Systemtechnik für Heim und Gebäude (ESHG) -- Teil 2-3: Systemübersicht - Anforderungen an die funktionale Sicherheit für Produkte, die für den Einbau in ESHG vorgesehen sind

Diese Europäische Norm legt die Anforderungen an die funktionale Sicherheit für ESHG-Produkte und  Systeme, ein universelles Bussystem, in dem die Funktionen dezentral verteilt und durch gemeinsame Kommunikationsprozesse verbunden sind, fest. Die Anforderungen können auch auf Funktionen von  Geräten, die in einem ESHG-System verbunden sind, angewendet werden, wenn für Gerät oder System keine bestimmte Norm zur funktionalen Sicherheit vorhanden ist. Die Anforderungen an die funktionale Sicherheit aus dieser Europäischen Norm gelten zusammen mit der entsprechenden Produktnorm für das Gerät, falls eine solche vorhanden ist. Diese Europäische Norm gilt für eine Produktfamilie. Es ist nicht beabsichtigt, sie außerhalb der Produktfamilie anzuwenden. Diese Europäische Norm beschreibt keine Anforderungen an die funktionale Sicherheit von sicherheitsbezogenen Systemen.

Systèmes électroniques pour les foyers domestiques et les bâtiments (HBES) -- Partie 2-3: Vue d'ensemble du système - Exigences générales de sécurité fonctionnelle pour les produits destinés à être intégrés dans les systèmes HBES

Cette Norme Européenne établit les prescriptions pour la sécurité fonctionnelle des systèmes et des produits HBES, un système de bus multi-applications où les fonctions sont distribuées, de manière décentralisées, et connectées au travers d’un processus commun de communication. Les prescriptions peuvent également s’appliquer aux fonctions distribuées de tout équipement connecté dans un foyer domestique ou  tout système de gestion du bâtiment, si aucune norme de sécurité fonctionnelle n’existe pour cet équipement ou ce système.  Les prescriptions de sécurité fonctionnelle de la présente Norme Européenne s’appliquent conjointement avec la norme de produit applicable pour ce dispositif, si elle existe. La présente Norme Européenne est utilisée comme une norme combinée de produit. Elle n’est pas destinée à être utilisée comme une norme isolée. La présente Norme Européenne ne fournit pas de prescriptions de sécurité fonctionnelle pour les systèmes relatifs à la sécurité.

Stanovanjski in stavbni elektronski sistemi (HBES) – 2-3. del: Sistemski pregled – Zahteve splošne funkcionalne varnosti za proizvode, ki so namenjeni za vgradnjo v HBES

General Information

Status
Withdrawn
Publication Date
31-Aug-2005
Withdrawal Date
28-Feb-2019
Current Stage
9900 - Withdrawal (Adopted Project)
Start Date
28-Feb-2019
Due Date
23-Mar-2019
Completion Date
01-Mar-2019

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EN 50090-2-3:2005
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SIST EN 50090-2-3:2005SLOVENSKIseptember 2005
STANDARDStanovanjski in stavbni elektronski sistemi (HBES) – 2-3. del: Sistemski pregled – Zahteve splošne funkcionalne varnosti za proizvode, ki so namenjeni za vgradnjo v HBESHome and Building Electronic Systems (HBES) – Part 2-3: System overview – General functional safety requirements for products intended to be integrated in HBES©
Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljenoReferenčna številkaSIST EN 50090-2-3:2005(en)ICS97.120







EUROPEAN STANDARD
EN 50090-2-3 NORME EUROPÉENNE EUROPÄISCHE NORM
February 2005 CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50090-2-3:2005 E
ICS 97.120
English version
Home and Building Electronic Systems (HBES) Part 2-3: System overview -
General functional safety requirements
for products intended to be integrated in HBES
Systèmes électroniques pour les foyers domestiques et les bâtiments (HBES) Partie 2-3: Vue d'ensemble du système - Exigences générales de sécurité fonctionnelle pour les produits destinés
à être intégrés dans les systèmes HBES
Elektrische Systemtechnik für Heim
und Gebäude (ESHG) Teil 2-3: Systemübersicht -
Anforderungen an die funktionale Sicherheit für Produkte,
die für den Einbau in ESHG
vorgesehen sind
This European Standard was approved by CENELEC on 2004-09-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.



EN 50090-2-3:2005 – 2 –
Foreword This European Standard has been prepared by the Technical Committee CENELEC TC 205, Home and Building Electronic Systems (HBES), joined by the co-operating partner Konnex Association.
The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50090-2-3 on 2004-09-01. The following dates were fixed: – latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement
(dop)
2005-09-01 – latest date by which the national standards conflicting with the EN have to be withdrawn
(dow)
2007-09-01 This European Standard shall be used as family standard; it is also addressed to Product Committees or, where no suitable product standards exist, to product manufacturer. EN 50090-2-3 is part of the EN 50090 series of European Standards, which will comprise the following parts: Part 1: Standardisation structure Part 2: System overview
Part 3: Aspects of application Part 4: Media independent layers Part 5: Media and media dependent layers Part 6: Interfaces
Part 7: System management Part 8: Conformity Part 9: Installation requirements TRs: CENELEC TC 205 Technical Reports __________



– 3 – EN 50090-2-3:2005
Contents Introduction.4 1 Scope.4 2 Normative references.4 3 Definitions.5 4 General requirements.7 4.1 General.7 4.2 Method of establishment for the requirements.8 4.2.1 HBES application environment.8 4.2.2 Sources of hazards.8 4.2.3 Hazardous events.8 4.2.4 Derivation of requirements.9 5 Requirements for functional safety.9 5.1 General.9 5.2 Power feeding.10 5.3 Environment.10 5.4 Life time.10 5.5 Reasonably foreseeable misuse.11 5.6 Software and communication.11 5.7 Remote operations.13 5.7.1 General recommendations.13 5.7.2 Within a single building or in its immediate vicinity.13 5.7.3 From outside the building.13 5.7.4 Management.14 Annex A (informative) Example of a method for the determination of safety integrity levels.15 Annex B (informative) Hazards and development of necessary Functional Safety
Requirements.17 Annex C (informative) Some examples of non safety related HBES applications.23 Bibliography.25 Figure A.1 – Risk reduction: General concept.15 Table 1 – Requirements for avoiding inadvertent operations and possible ways to achieve them.14 Table A.1 – Example of risk classification of accidents.16 Table A.2 – Interpretation of risk classes.16



EN 50090-2-3:2005 – 4 –
Introduction HBES products integrated in a HBES should be safe for the use in intended applications. This European Standard specifies the general functional safety requirements for HBES following the principles of the basic standard for functional safety EN 61508 and Technical Report R205-012 in particular. This European Standard identifies functional safety issues related to products and their installation. The requirements are based on a risk analysis in accordance with EN 61508. The intention of this European Standard is to allocate, as far as possible, all safety requirements for HBES products in there life cycle.
This European Standard only addresses HBES products.
This European Standard is addressed to committees that develop or modify HBES product/system standards or, where not suitable HBES product standards addressing functional safety exist, to product manufacturer. HBES and HBES products in this European Standard are for non-safety related applications. Additional requirements for safety related HBES will be described, according to EN 61508, in Part 2-4 of the EN 50090-series (under consideration). 1 Scope This European Standard sets the requirements for functional safety for HBES products and systems, a multi-application bus system where the functions are decentralised, distributed and linked through a common communication process. The requirements may also apply to the distributed functions of any equipment connected in a home or building control system if no specific functional safety standard exist for this equipment or system.
The functional safety requirements of this European Standard apply together with the relevant product standard for the device if any. This European Standard is used as a product family standard. It is not intended to be used as a stand-alone standard. This European Standard does not provide functional safety requirements for safety-related systems.
2 Normative references The following referenced documents are indispensable for the application 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. EN 50090-2-1 Home and Building Electronic Systems (HBES) – Part 2-1: System overview - Architecture EN 50090-2-2 Home and Building Electronic Systems (HBES) – Part 2-2: System overview - General technical requirements EN 61508-4:2001 Functional safety of electrical/electronic/programmable electronic safety-related systems – Part 4: Definitions and abbreviations
(IEC 61508-4:1998 + corrigendum 1999)



– 5 – EN 50090-2-3:2005
EN 61508-5:2001 Functional safety of electrical/electronic/programmable electronic safety-related systems – Part 5: Examples of methods for the determination of safety integrity levels (IEC 61508-5:1998 + corrigendum 1999) EN 61709:1998 Electronic components - Reliability - Reference conditions for failure rates and stress models for conversion (IEC 61709:1996) CEN/CLC Guide 9 Guidelines for the inclusion of Safety Aspects in standards (ISO/IEC Guide 51) EN ISO 9000 series Quality management systems 3 Definitions For the purposes of this document, the following terms and definitions apply.
3.1 architecture specific configuration of hardware and software elements in a system [EN 61508-4:2001, definition 3.3.5] 3.2 authentication means for certifying that the entity sending a message is what or who it purports to be and confirmation that the message is identical to that which was sent 3.3 authorisation mechanism to ensure that the entity or person accessing information, functions or services has the authority to do so 3.4 disturbed communication where for any reason a message being communicated is incomplete, truncated, contains errors or has the correct format but delivers information which is outside the range of expected parameters for such a message 3.5 functional safety freedom from unacceptable risk of harm due to the operation of an HBES, including that resulting from 1) normal operation, 2) reasonably foreseeable misuse, 3) failure, 4) temporary disturbances NOTE 1 Definition of EN 61508-4:2001, 3.1.9: part of the overall safety relating to the EUC (Equipment Under Control) and the EUC control system which depends on the correct functioning of the Electrical/Electronic/Programmable Electronic (E/E/PE) safety related systems, other technology safety related systems and external risk reduction facilities. NOTE 2 Definition of IEC TR3 61000-2-1 and IEC TS 61000-1-2 (IEC/TC 77) are taken into account. 3.6 Hamming distance numbers of bits in which two binary codes differ



EN 50090-2-3:2005 – 6 –
3.7 harm physical injury or damage to the health of people either directly or indirectly as a result of damage to property or to the environment
[EN 61508-4:2001, definition 3.1.1] 3.8 hazard a potential source of harm
[CEN/CLC Guide 9, respectively ISO/IEC Guide 51:1990] NOTE The term includes danger to persons arising within a short time scale (for example, fire and explosion) and also those that have a long-term effect on a person’s health (for example, release of a toxic substance). [EN 61508-4:2001, definition 3.1.2] 3.9 hazardous event situation which results in harm on normal operation or abnormal condition NOTE Definition of EN 61508-4:2001, 3.1.3 and 3.1.4: circumstance in which a person is exposed to hazard(s) which results in harm 3.10 HBES, Home and Building Electronic Systems a multi-application bus system where the functions are decentrally distributed and linked through a common communication process NOTE HBES is used in homes and buildings plus their surroundings.
Functions of the system are e.g: switching, open loop controlling, closed loop controlling, monitoring and supervising. 3.11 HBES product HBES products consist of devices in the form of hardware, firmware, their associated software and of configuration tools, intended to be used in an HBES 3.12 product HBES products consist of devices in the form of hardware, firmware, their associated software and of configuration tools 3.13 product documentation – the manufacturer's installation and operations literature which accompanies the product; – the product information contained in the manufacturer's catalogue and other product marketing material-information; – the description, definitions, product literature and usage as presented in electronic format on the manufacturer's (or supplier's) website on the World Wide Web/Internet 3.14 safety related system designated system that both – implements the required safety functions necessary to achieve or maintain a safe state for the EUC, and – is intended to achieve on its own or with other E/E/PE safety related systems, other technology safety-related systems or external risk reduction facilities, the necessary safety integrity for the required safety functions.



– 7 – EN 50090-2-3:2005
NOTE 1 The term refers to those systems, designated as safety-related systems, that are intended to achieve, together with the external risk reduction facilities (see EN 61508-4:2001, definition 3.4.3), the necessary risk reduction in order to meet the required tolerable risk (see EN 61508-4:2001, definition 3.1.6). See also Annex A of EN 61508-5:2001. NOTE 2 The safety-related systems are designed to prevent the EUC from going into a dangerous state by taking appropriate action on receipt of commands. The failure of a safety-related system would be included in the events leading to the determined hazard or hazards. Although there may be other systems having safety functions, it is the safety-related systems that have been designated to achieve, in their own right, the required tolerable risk. Safety-related systems can broadly be divided into safety-related control systems and safety-related protection systems, and have two modes of operation (EN 61508-4:2001, definition 3.5.12). NOTE 3 Safety-related systems may be an integral part of the EUC control system or may interface with the EUC by sensors and/or actuators. That is, the required safety integrity level may be achieved by implementing the safety functions in the EUC control system (and possibly by additional separate and independent systems as well) or the safety functions may be implemented by separate and independent systems dedicated to safety. NOTE 4 A safety-related system may a) be designed to prevent the hazardous event (i.e. if the safety-related systems perform their safety functions then no hazardous event arises), b) be designed to mitigate the effects of the hazardous event, thereby reducing the risk by reducing the consequences, c) be designed to achieve a combination of a) and b). NOTE 5 A person can be part of a safety-related system (EN 61508-4:2001, definition 3.3.1). For example, a person could receive information from a programmable electronic device and perform a safety action based on this information, or perform a safety action through a programmable electronic device. NOTE 6 The term includes all the hardware, software and supporting services (for example, power supplies) necessary to carry out the specified safety function (sensors, other input devices, final elements (actuators) and other output devices are therefore included in the safety-related system). NOTE 7 A safety-related system may be based on a wide range of technologies including electrical, electronic, programmable electronic, hydraulic and pneumatic. [EN 61508-4:2001, definition 3.4.1] 3.15 risk combination of the probability of occurrence of a harm and the severity of that harm [CEN/CLC Guide 9, respectively ISO/IEC Guide 51:1990, modified]
[EN 61508-4:2001, definition 3.1.5] NOTE For risk classes see Annex A. 3.16 reasonably foreseeable misuse the use of a product, process or service under conditions or for purposes not intended by the supplier, but which may happen,
induced by the product, process or service in combination with, or as result of, common human behaviour [EN 61508-4:2001, definition 3.1.11] 3.17 safety function function to be implemented by an E/E/PE safety related system, other technology safety-related systems or external risk reduction facilities, which is intended to achieve and maintain a safe state for the EUC, in respect of a specific hazardous event (see EN 61508-4:2001, definition 3.4.1) [EN 61508-4:2001, definition 3.5.1] 4 General requirements 4.1 General Functional safety of a system relies upon both the performance of the network, and upon the performance of the connected HBES products. 1) Failure of either the network or any other part of HBES system shall not cause the system, the products, or the controlled equipment to become unsafe. 2) Whilst in operation, individual HBES products shall not rely solely upon the system for their safe operation.



EN 50090-2-3:2005 – 8 –
3) While in operation, the systems interaction of any product(s) with any other product(s) shall not result in unsafe operation of the system. 4.2 Method of establishment for the requirements For specification of the functional safety requirements the life-cycle used in EN 61508 was followed: 1) concept phase of products; 2) application environment; 3) identification of hazards and hazard events; 4) hazard and risk analysis, risk reduction measures; 5) realisation of risk reduction measures; 6) validation; 7) maintenance; 8) installation and commissioning; 9) decommissioning. The Product Technical Committees and/or developers shall take the requirements of this European Standard into account in the product safety requirements, but it is not necessary to go into the EN 61508 process itself. 4.2.1 HBES application environment The HBES application environment is taken into account. 4.2.2 Sources of hazards The following sources of hazards have been considered: 1) material and construction; 2) reliability; 3) normal operation; 4) unintentional interaction with other products; 5) interaction with other HBES products; 6) abnormal conditions; 7) foreseeable misuse, including the download of unauthorised and malicious code; NOTE This includes unintentional software modifications. 8) life time; 9) environment. 4.2.3 Hazardous events The following hazardous events have been taken into account for the analysis (the bus and mains (230 V/400 V) have been considered): 1) power failure; 2) short circuit of bus line; 3) overvoltage on the bus line; 4) overvoltage on the mains; 5) insulation damage (temperature, surge, mechanical); 6) wrong connection;



– 9 – EN 50090-2-3:2005
7) over temperature; 8) fire; 9) mechanical shock, vibration; 10) corrosion; 11) electromagnetic disturbance; 12) disturbed communication; 13) pollution; 14) end of life time of a component/products; 15) reasonably foreseeable misuse; 16) software failure; 17) overload; 18) loss of reliability; 19) breakdown of material (mechanically); 20) inappropriate design/construction; 21) switching of damaged equipment and subsystems; 22) remote control; 23) command from two sources to one product (e.g. actuator); 24) system failures. 4.2.4 Derivation of requirements
The risk analysis has been carried out for each of the hazard events; see Annex B.
The likelihood of the event has been estimated and the risk class has been taken in account according to the method of Annex A. In all cases where the evaluated risk classes indicate an unacceptable risk, risk reduction measures are requested as well as the level of risk reduction effect and its validation. Some risk reduction measures are proposed and what is usually covered by the relevant product standard is also indicated. If manufacturers intend to develop HBES products/systems which exhibit hazardous events not covered by 4.2.3 the risk analysis shall be carried out according to EN 61508. 5 Requirements for functional safety NOTE Reference to the hazardous events of 4.2.3 are given within brackets (
). 5.1 General Analysis according to EN 61508 indicates that functional safety depends upon both the design and manufacture of products and upon the appropriate use of the products in installations. Subclauses 5.2 to 5.7 contain requirements for HBES products and for the provision of information necessary for the proper installation, operation and maintenance of these products. Compliance requirements are given for the products as necessary and verification of the provision of the necessary information. All referenced product tests are type tests. The basis and reasons of the following requirements are shown in the Annex B.



EN 50090-2-3:2005 – 10 –
5.2 Power feeding 5.2.1 In case of power failure the products shall restart safely when power is restored. (1) NOTE Safe restart can be performed by – storing the status information and usage the information for rebuilding the functionality after power on, – switching to a defined state of the product depending on the application of the products, – calculation of the safe state based on the information available from the system (from a controller, if any and/or from each product), – maintaining a sufficient power reserve (by providing an appropriate buffer time either in the product and/or in the
Power Supply Unit) to enable connected products to assume a safe state. 5.2.2 Marking and instructions of the products shall be designed to prevent the risk of wrong connections. (3) (6) The products shall be marked in a legible and durable manner. Compliance shall be checked by inspection of the product documentation and if appropriate according to the test of legible and durable markings in the relevant product standard. 5.2.3 The construction and design of a product shall prevent wrong connections. This may be supported by appropriate grouping of connections. (6) Compliance shall be checked by inspection of the product. 5.3 Environment 5.3.1 Products shall be designed for the working temperature appropriate to their maximum rated voltages needed for the application environment and shall work properly in the specified temperature range. (7) Compliance shall be checked by testing the product according to the relevant product standard and if this does not exist to EN 50090-2-2 and the relevant basic safety standards. 5.3.2 The products and components shall be designed for resistance to abnormal heat and shall not propagate fire. (8) Compliance shall be checked by testing the product according to the relevant product standard and if this does not exist to the relevant basic safety standards. 5.3.3 The products shall be designed to withstand the mechanical stress appropriate to the application(s). (9) Compliance shall be checked by testing the product according to the relevant product standard and if this does not exist to EN 50090-2-2 and the relevant basic safety standards. 5.4 Life time The products shall be designed for a defined useful lifetime according to EN 61709:1998, Subclause 5.2 and Annex A or defined number of switching cycles under normal condition. The Datasheet shall give instructions for maintenance if required to reach the specified lifetime. (14) Compliance shall be checked by inspection of the documentation.



– 11 – EN 50090-2-3:2005
5.5 Reasonably foreseeable misuse 5.5.1
The risk of accidental download of the wrong application software or parameters into the products shall be minimised. (15) NOTE The following measures may apply: – design of the configuration tool; – identification of products and comparison of their profiles by the network management; – password; – authentication; – product documentation; – training of installers/operators. Compliance shall be checked by product test and/or inspection of the product documentation. 5.5.2 Proper configuration and related parameters shall be ensured. (15) NOTE The following measures may apply: – specification of parameter ranges; – limited configuration possibilities for the end-user; – access to configuration only for skilled persons (see EN 50090-2-1); – consistency check by tools or by the installer; – check of conformity with configuration. Compliance shall be checked by check of conformity of existing with planed (intended) configuration. 5.5.3
Measures shall be provided for the detection and/or indication of missing or incompletely configured products during the configuration process. (15) NOTE The following measures may apply: – design of the configuration tool; – formal installation procedures. Compliance shall be checked by product test or inspection of the product documentation. 5.6 Software and communication 5.6.1 The Software development process shall comply with EN ISO 9000 or similar standards. (16) Compliance shall be checked by inspection of the process documentation or of the corresponding certificates. 5.6.2 Measures shall be provided to check for the proper operation of the product software and the integrity of the configuration. If abnormal operation is detected, the product shall restore the correct values or shall go to a defined state. (16) Compliance shall be checked by inspection of the product software design documentation. 5.6.3 Measures, if required by the application, shall be provided inside the products to limit the traffic load imposed on the communication medium. (12) (17) NOTE The following measures may apply: – limitation of cyclic transmission; – limitation of the number of messages per time unit per product; – limitation of polling cycles. Compliance shall be checked by inspection of the product documentation and if possible by product testing.



EN 50090-2-3:2005 – 12 –
5.6.4
The reception of messages from several sources shall not disturb the proper function of the product and shall not cause hazards. (23) NOTE The following measures may apply: – check source address in case there is a hierarchy of the sources; – apply the rule: first in, first out; – apply the rule: last message wins; – secure the process by finalising before new messages may change the behaviour; – secure the process by stopping and restarting the process; – secure the process by disabling and enabling the process. Compliance shall be checked by inspection of the product documentation and if possible by product testing. 5.6.5 The products shall respond to a system reset (if any) by going to a defined state. (24) Compliance shall be checked by inspection of the product documentation and if possible by product testing. 5.6.6 It shall be possible to restrict access to the manual configuration of system parameters. (24) NOTE The following measures or exceptions may apply: – use of a tool (hardware or software); – use of password and/or authentication; – ensure that unauthorised access is not possible; – combination or sequence of actions; – concealed means for configuration; – except where manual configuration is explicitly detailed in its instruction manual (also the case for automatic configuration). Compliance shall be checked by inspection of the product documentation and if possible by product testing. 5.6.7 Disturbed communication 5.6.7.1 The safe operation of a product shall be independent of the operation of other products in the system or application. (12) NOTE The following measures may apply: – cyclic transmission; – range checking of received variables. Compliance shall be checked by inspection of the results of the product test or by inspection of the product documentation.
5.6.7.2 Measures for the identification of disturbed messages shall be provided. In case of detection of a disturbed messages, measures shall be taken to ensure safe operation. The Hamming distance shall be not lower than 2. (11) (12) NOTE The following measures may apply: – the message may be rejected or corrected by the receiving product; – the message may be repeated by the sender. Compliance shall be checked by inspection of the results of the product tes
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