ISO INTERNATIONAL STANDARD 4902 Second edition 1989-12-01 Information technology Data communication - 37-pole DTE/DCE interface connector and contact number assignments Technologies de I'information - Communication de donnees - Connecteur d'interface ETTD/ETCD a 37 poles et affectation des numeros de contact Reference number ISO 4902 : 1989 (E) Copyright Intermational Organization for Standardization cense with IS permitted without license from IHS Not for Resale ISO 4902 : 1989 (E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of nationalstandardsbodies(iSOmemberbodies).TheworkofpreparingInternational Standardsis normallycarriedoutthroughIsOtechnicalcommittees.Eachmember therighttobe represented onthat committee.International organizations,govern- mental and non-governmental, in liaison with Iso, also take part in the work. Iso collaborates closely with the International Electrotechnical Commission (IEC) on all mattersof electrotechnicalstandardization. the member bodies for approval before their acceptance as International Standards by the ISo Council. They are approved in accordance with ISO procedures requiring at International Standard ISO 4902 was prepared by Technical Committee ISO/TC 97, Information processing systems. This second edition cancels and replaces the first edition (ISO 4902 : 1980), of which it constitutes a minor revision: certain terms have been aligned with the terms and defi- nitions used by IEC. Annexes A, B and C of this International Standard are for information only. ISO 1989 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56CH-1211Geneve 20Switzerland Printed in Switzerland CopyrightIntemationalOrganizatinfor Standardization rmitted without license from IHS Not for Resale INTERNATIONALSTANDARD ISO 4902 : 1989 (E) Information technology -- Data communication 37-pole DTE/DCE interface connector and contact number assignments 1 Scope CCITT Recommendation V.28 : 1989, Electrical characteristics for unbalanced double-current interchange circuits. ThisInternationalStandard specifiesthe37-poleconnectorand theassignment ofcontactnumbersatthe interfacebetween CCITT Recommendation V.36 : 1989, Modems for synchron- data terminal equipment (DTE) and data circuit-terminating ous data transmission using 60-108 kHz group band circuits. equipment (DCE) where CCITT1) Recommendation V.24 together with Recommendations V.10 and V.11 are applicable. CCITT Recommendation V.37 : 1989, Synchronous data transmission at a data signalling rate higher than 72 kbit/s International Standard ISO4902additionallyprovides the using 60-108 kHz group band circuits. dimensions of the connector housing, as well as the recom mended means of providing a locking device (latching block) IEc Publication 50(581) : 1978, International Electrotechnical and connector shielding. Vocabulary -- Chapter 581 : Electromechanical components for electronic equipment. 2 Normative references IEC Publication 807-2 : 1985, Rectangular connectors for fre quenciesbelow3MHz Part2:Detail specificationfora The following standards contain provisions which, through range of connectors with round contacts -Fixed solder con- reference in this text, constituteprovisions of this Internationa tact types. Standard. At the time of publication,the editions indicated were valid.Ail standards are subject to revision,and parties to agreements based on this International Standard are encour- 3 Definitions aged to investigate the possibility of applying the most recent editions of the standards listed below.Members ofIEC and ISO The following definitions have been taken from IEC Publication maintain registers of currentlyvalid International Standards. 50(581):1978. ISO 261 : 1973, /SO general purpo