Revised Standard from Last Update.

NATIONAL FOREWORD

This Indian Standard (Part 2) (First Revision) which is identical with IEC 61508-2 : 2010 ‘Functional safety of electrical/electronic/programmable electronic safety-related systems — Part 2: Requirements for electrical/electronic/programmable electronic safety related systems’ issued by the International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on recommendation of the Industrial Process Measurement and Control Sectional Committee and approval of the Electrotechnical Division Council.

This standard was originally published in 2008 which was identical with IEC 61508-2 : 2000. The first revision of this standard has been undertaken to align it with the latest version of IEC 61508-2 : 2010.

This Indian Standard supersedes the IS/IEC 61508-2 : 2000.

The E/E/PE requirements specification in Edition 1 of IS/IEC 61508 comprised a single specification (i.e. a single step process). Edition 2 of IS/IEC 61508 comprises two specifications (i.e. a two step process) namely:

a) Step 1: Develop the E/E/PE system safety requirements specification (in IS/IEC 61508-1); and

b) Step 2: Develop the E/E/PE system design requirements specification (in IS/IEC 61508-2).

The text of IEC Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminologies and conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker.