NATIONAL FOREWORD

This Indian Standard which is identical with ISO/IEC 7480 : 1991 ‘Information technology — Telecommunications and information exchange between systems — Start-stop transmission signal quality at DTE/DCE interfaces’ issued by the International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC) jointly was adopted by the Bureau of Indian Standards on the recommendations of Information and Communication Technology Sectional Committee and approval of the Electronics and Information Technology Division Council.

IS 12285 was first published in 1987 and was identical to ISO 7480 : 1984. This standard is now being revised to align it with the latest ISO/IEC Publication 7480 : 1991.

The text of ISO/IEC Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain conventions and terminologies 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’; and

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.