BS EN BRITISH STANDARD 61866:1997 IEC 61866: 1997 Audiovisual systems Interactive text transmission system (ITTS) The European Standard EN 61866:1997 has the status of a British Standard ICS 33.160.99 BSi BS EN 61866:1997 National foreword This British Standard is the English language version of EN 61866:1997. It is identical with IEC 61866:1997. The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and multimedia systems and equipment, to Subcommittee EPL/100/3, Equipment and systems in their field of audio, video and audiovisual engineering, which has the responsibility to: - aid enquirers to understand the text; - present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UKinterests informed; - monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. From 1 January 1997, all IEC publications have the number 60000 added to the old number. For instance, IEC 27-1 has been renumbered as IEC 60027-1. For a period of time during the change over from one numbering system to the other, publications may contain identifiers from both systems. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled "International Standards Correspondence Index", or by using the “Find" facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and i, the EN title page, pages 2 to 46 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated.This willbe indicatedintheamendmenttableon the inside front cover. This British Standard, having Amendments issued since publication censed been prepared underthe direction of the Electrotechnical Amd. No. Date Comments Sector Board, was published under the authority of the Standards Board and comes into effect on 15 December 1997 CBSI04-1999 ISBN 0 580 28869 2 BS EN 61866:1997 Contents Page National foreword Inside front cover Foreword 2 Text of EN 61866 5- CBSI 04-1999 1