IEC 61508-4 PDF

3 Dec IEC Standard | functional safety, smart city | Functional safety of electrical/electronic/programmable electronic safety-related. 12 May 4) In order to promote international unification, IEC national IEC has been prepared by sub-committee 65A: System aspects, of IEC. IEC contains the definitions and explanation of terms that are used in parts 1 to 7 of the IEC series of standards. The definitions are.

Author: Gardazragore Kigacage
Country: Mexico
Language: English (Spanish)
Genre: Finance
Published (Last): 12 November 2011
Pages: 497
PDF File Size: 17.18 Mb
ePub File Size: 13.5 Mb
ISBN: 232-9-11120-895-6
Downloads: 30484
Price: Free* [*Free Regsitration Required]
Uploader: Mukora

Any safety strategy must therefore consider not only all iex elements withm an individual system for example sensors, controlling devices and actuators but also all the safety-related systems making up the total combination of safety-related systems.

Software requirements lEC Examples of methods for the determination of safety integrity levels lEC Certain conventions are, however, not identical to those used in Indian Standards. This does not preclude the free use, in course of implementing the standard, of necessary details, such as symbols and sizes, type or grade designations.

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. An example of such a fault is a design fault.

IEC | IEC Webstore | functional safety, smart city

This Indian Standard has been developed from Doc: For dated references, subsequent amendments to, or revisions of, any of these publications do not apply However, parties to agreements based on this part of lEC are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. No part of these publications may be reproduced in any form without the prior permission in writing of BIS.

The failure of a safety-related system would be included m the events leading to the determined hazard or hazards. In this adopted standard, reference appears ic certain International Standards for which Indian Standards also exist. A major objective is to facilitate the development of application sector standards.


Fundamental terms ISO Dependability and quality ice service lEC See also annex A of lEC 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.

Automatic control lEC If separate channels are used, these tests are done for each channel separately. NOTE 3 – The term safe diagnostic coverage, or diagnostic coverage including sate failures, is used to descnbe respectively the fractional decrease in the probability of safe hardware failure, or of both safe and dangerous hardware failures, resulting from the operation of the automatic diagnostic tests 3.

Computer-based systems genencally referred to as programmable electronic systems PESs are being used in iev application sectors to perform non-safety functions and, increasingly, to perform safety functions. Review of Indian Standards Amendments are issued to standards as the need arises on the basis of comments.

Data processing – Vocabulary – Part Overview of techniques and measures ISO Figure 4 – Failure model 3. Definitions and abbreviations [ETD In most situations, safety is achieved by a number of protective systems which rely on many technologies for example mechanical, hydraulic, pneumatic, electrical, electronic, programmable electronic.

If computer system technology is to be effectively and safely exploited, it is essential that those responsible for making decisions have sufficient guidance on the safety aspects on which to make ic decisions.


Users of Indian Standards should ascertain that they are in possession of the latest amendments or edition by referring to the latest issue of ‘BIS Catalogue’ and ‘Standards: NOTE 2 – The term can be used to describe a complete system, or a portion of a system for example, sensors or final elements. Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

Programming languages I EC 61 General requirements lEC EXAIWPLE Verification activities include – reviews on outputs documents from all phases of the safety lifecycle to ensure compliance with the objectives and requirements of the phase, taking into account the specific inputs to that phase; design reviews: For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test, shall be rounded off in accordance with IS 2: The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.

Figure 2 — Programniable electronic system PES: