1、I N T E R N AT IO N A L STANDARD IS0 4903 Second edition 1989-10-01 (Reaffirmed 2004) Information technology - Data communication - 15-pole DTE/DCE interface connector and contact number assignments Technologies de linformation - Communication de donnees - Connecteur dinterface ETTD/ETCD a 15 pbles
2、et affectation des numeros de contact National Standard of Canada CAN/CSA -IS0-4903-95 International Standard IS0 4903: 1989 has been adopted, without modification, as CAN/CSA-ISO- 4903-95, which has been approved as a National Standard of Canada by the Standards Council of Canada. February 1995 Ref
3、erence number IS0 4903 : 1989 (El IS0 4903 : 1989 (E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees.
4、Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the Intern
5、ational Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. They are approved in
6、 accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 4903 was prepared by Technical Committee ISO/TC 97, Information processing systems. This second edition cancels and replaces the first edition (IS0 4903 : 19801, of which it const
7、itutes a minor revision; certain terms have been aligned with the terms and defi- nitions used by IEC. 0 IS0 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 permis
8、sion in writing from the publisher. International Organization for Standardization Case postale 56 CH-1211 Gengve 20 Switzerland Printed in Switzerland INTERNATIONAL STANDARD Information technology - Data communication - 15-pole DTE/DCE interface connector and contact number assignments 1 Scope This
9、 International Standard specifies the 15-pole connector and the assignment of contact numbers at the interface between data terminal equipment (DTE) and data circuit-terminating equipment (DCE) where CClTT ) Recommendations X.24, x26, and X.27 are applicable. International Standard ISO/IEC 4903 addi
10、tionally provides the dimensions of the connector housing, as well as the recom- mended means of providing a locking device (latching block) and connector shielding. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this
11、 International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encour- aged to investigate the possibility of applying the most recent editions of the standards indicate
12、d below. Members of IEC and IS0 maintain registers of currently valid International Stan- dards. IS0 261 : 1973, IS0 general purpose metric screw threads - General plan. IS0 21 10 : 1989, Information technology - Data communi- cation - 25-pole DTE/DCE interface connector and contact number assignmen
13、ts. CClTT Recommendation V.28 : 1989, Electrical characteristics for unbalanced double-current interchange circuits. CClTT Recommendation X.20 : 1989, lnterface between data terminal equipment (0 TEI and data circuit-terminating equip- ment (LICE) for start-stop transmission services on public data
14、ne tworks. CClT Recommendation X.21 : 1989, lnterface between data terminal equipment IDTEI and data circuit-terminating equb- ment (DCEI for synchronous operation on public data ner- works. CCllT Recommendation X.22 : 1989, Multiplex DTE/DCE interface for user classes 3-6. CCllT Recommendation X.24
15、 : 1989, List of definitions for interchange circuits between data terminal equipment ID TE) and data circuit-terminating equipment (DCEI on public data network. CClTT Recommendation X.26 (or V.101 : 1989, lectrica/ characteristics for unbalanced double-current interchange cir- cuits for general use
16、 with integrated circuit equipment in the field of data communications. CClTT Recornmendation X.27 (or V.ll) : 1989, Electrical characteristics for balanced double-current interchange circuits for general use with integrated circuit equipment in the field of data communications. IEC Publication 50(5
17、81 I : 1978, International Electrotechnical Vocabulary - Chapter 581 : E/ectromechanical components for electronic equipment. IEC Publication 807-2 : 1985, Rectangular connectors for fre- quencies below 3 MHz - Part2: Detail specification for a range of connectors with round contacts - Fixed solder
18、con- tact types. 3 Definitions The following definitions have been taken from IEC Publication W(581) : 1978. 3.1 cable adaptor: A part of a connector or an accessory consisting of a rigid housing for attachment to the connector body. It may incorporate provision for a cable clamp or seal for termina
19、ting screens and provide shielding from electrical interference. It may be straight or angled. 3.2 the insert and contacts are assembled. connector housing: A part of a connector into which 3.3 figuration of contacts in a component. contact arrangement: The number, spacing and con- 1) International
20、Telegraph and Telephone Consultative Committee. 1 IS0 4903 : 1989 (E) 3.4 female contact: A contact intended to make electrical engagement on its inner surface and which will accept entry of a male contact. 3.5 intermateable connectors: Two connectors are inter- mateable when they are capable of bei
21、ng connected electrically and mechanically but without regard to their performance and intermountability. 3.6 locking device: A feature incorporated in certain com- ponents to provide mechanical retention of their mating part. 3.7 male contact: A contact intended to make electrical engagement on its
22、 outer surface and which will enter a female contact. 3.8 (n-pole-)connector : A component which terminates conductors for the purpose of providing connection and disconnection to a suitable mating component. 4 Connector Figures 1 to 5 illustrate the 15-pole interface connector. Only those dimension
23、s that are essential to mating are shown. Figure 1 illustrates the DTE connector which has 15 male con- tacts in a connector housing. Figure 2 illustrates the DCE con- nector which has 15 female contacts in a connector housing. The connector housing on the DCE connector is dimensioned to fit inside
24、the connector housing on the DTE connector (see figures 1 and 2). Contact numbering is specified in figures 1 and 2. Figure 3 ilustrates the dimensions for the contact spac- ing. Figures 4 and 5 illustrate the dimensions for the male and female contacts respectively. The DCE connector shall be equip
25、ped with a locking device consisting of two latching blocks as specified in figure 2. Due to the fact that the latching blocks have threaded holes which can act as nuts, the DTE connector may be equipped either with lever devices for latching to the latching blocks on the DCE connector or with screw
26、s that fit into the threaded holes in the latching blocks. The thread of the latching blocks shall be M3 as specified in figure 2. Sufficient connector dimensions are provided in this Inter- national Standard to ensure intermateable connectors. They are consistent with the detailed connector specifi
27、cation in IEC Publication 807-2. In annex A, diagrams for finger clearance areas are given to provide guidance for equipment designers. Figure A. 1 shows the maximum DTE connector outline including all means for latching to the latching blocks. Figure A.2 shows the minimum DCE connector spacing when
28、 multiple interface arrangements are used. 5 Assignment of contact numbers The assignment of contact numbers for the interchange circuits specified in CClTT Recommendations X.20, X.21 and X.22 is given in table 1 for implementations using X.26 and X.27 elec- trical characteristics. Additionally, con
29、tact 1 is reserved for con- nection of the shield of shielded interconnecting cable. Table 2 gives a list of interchange circuits and their description. Their provision and use shall be in conformity with the corresponding CClTT DCE Recommendations. 6 Connector shielding Connector shielding is optio
30、nal. If it is used, for example due to national regulations, etc., it shall be accomplished by the use of metallic connector housings on both the DTE connector and the DCE connector. 7 Interconnecting configurations for mixed use of X.26, X.26 and V.28 electrical characteristics Considerations for t
31、he interworking of equipment implement- ing X.26 on one side of the interface with equipment implementing X.27 on the other side of the interface are given in annex A.2 of CCITT Recommendations X.26 and X.27. In addition, the definition of the category 1 and 2 receiver configu- rations is provided i
32、n V.10. Guidance concerning possible interconnecting configurations applicable to the X.20 and X.21 interfaces is provided in annex B. Guidance concerning the necessary adaptation when there is a need for X.20 DCE implementing X.26 characteristics to interwork with X.20 DTE implementing V.28 charact
33、eristics is given in annex C. Any adapters required to accomplish the interworking with equipment meeting the V.28 requirements shall be provided with equipment meeting the requirements of this International Standard, i.e., the X.2O/X.26 DCE. No re- visions or modifications shall be required in the
34、equipment using V.28 electrical characteristics. 2 IS0 4903 : 1989 (E) Circuit designation G Ga Gb T R C I S B F X Table 1 - Assignment of contact numbers for interface CCllT Recommendations X.20, X.21, and X.22 Description Signal ground or common return DTE common return DCE common return Transmit
35、Receive Control I nd icatio n Signal element timing Byte timing Frame start identification DTE transmit signal element timing Contact nu m be r 61 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 NOTES Interchange circuit assignment x.203 X.26 X.275) x.2131 Reserved for future international use X.22 X.2751 1 Con
36、tact 1 is assigned for connecting the shields between tandem sections of shielded interface cable. The shield may be connected either to protective ground or to signal ground at either the DTE or DCE or both in accordance with national regulations. Signal ground may be further connected to protectiv
37、e ground in accordance with national safety regulations. Caution should be exercised to avoid establishment of ground loops carrying high currents. 2 DTEs may employ either X.26 or X.27 electrical characteristics to operate with DCEs using X.26 electrical characteristics in accordance with X.20. 3 D
38、TEs may employ either X.26 or X.27 electrical characteristics to operate with DCEs using X.27 electrical characteristics in accordance with X.21 for data signalling rates of 9,6 kbitis and below. Only X.27 applies above 9,6 kbit/s. 4 The assignment of contact numbers has been chosen considering inte
39、rworking between X.26 DTE and X.27 DCE using the considerations given in annex 2 of Recommendations X.26 and X.27. 5 Where balanced circuits are concerned, the associated pairs are designated “A“ and “B“ in X.27. 6 The assignment of contact numbers has been aligned to specify pairing and connection
40、to multipaired interconnecting cable. Respective paired contacts are 2 and 9, 3 and IO, ., 8 and 15. 7 Circuit X is used if the DTE has to provide signal element timing. 3 IS0 4903 : 1989 (E) I R 2,69 R 2,59 i P NN am - a? OQOOOQOO 0000000 10 12 14 15 DTE contact arrangement viewed from connector fr
41、ont (DCE side) 2 5,37 Dimensions in millimetres I f f Figure 1 - DTE connector 4 IS0 4903 : 1989 (E) Dimensions in rnillirnetres DCE contact arrangement viewed from connector front (DTE side) 33,45 3 3,2 / r 2,54 M3 thread11 3,175 minimum - f depth available - for DTE screw R 1,575 Latching block 21
42、 1) Metric thread per IS0 261, /SO general purpose metric screw threads - General plan. 2) Unless otherwise specified, tolerances shall be : I 2 decimal places k 0,51 10 typical b) X.26 generator signal risetime should be no slower than loo ps; c) L-pad attenuator, if needed, on circuit T in adapter
43、; d) connect signal return circuits Ga and Gb together with circuit G (if implemented) from the X.20/X.26 DCE to circuit G from the X.20/V.28 DTE in the adapter; e) when the L-pad attenuator is used on circuit T, install adapter such that the cable length between the adapter and the X.26 DCE does no
44、t exceed 3 m; f) total cable length between the X.26 DCE and the V.28 DTE is limited to the length normally associated with V.28 operation. V.28 generator X.26 receiver - - Figure C.l - L-pad attenuator for protection of X.26 receiver 16 IS0 4903 : 1989 (E) X.201V.28 25 Adapter 15 - DTE L X. 20/X.26
45、 DCE i- Figure C.2 - Interconnection configuration with 25/15-pole adapter 8 9 10 11 12 13 14 15 I so 2110 X. 20/V. 2 8 DTE + T R G G Ga Gb E a 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Adapter 1 2 3 4 5 6 7 b IS0 4903 X.20/X.26 DCE 4- T R Figure C.3 - Adapter wiring diagram 17 IS0 4903 : 1989 (E)
46、 UDC 681.327.8 : 621.316.541 Descriptors : data processing, data transmission, network interconnection, data communication equipment, connecting equipment, electric connectors, connector pins, multi-contact connectors, specifications, dimensions, layout, numbering. Price based on 17 pages National S
47、tandards Information Standards development within the Information Technology sector is harmonized with international standards development. Through the CSA Technical Committee on Information Technology (TCIT), Canadians serve as the Canadian Advisory Committee (CAC) on ISO/IEC Joint Technical Commit
48、tee 1 on Information Technology (ISO/IEC JTC1) for the Standards Council of Canada (SCC), the IS0 member body for Canada and sponsor of the Canadian National Committee of the IEC. Also, as a member of the International Telecommunication Union (ITU), Canada participates in the International Telegraph
49、 and Telephone Consultative Committee (ITU-T). This International Standard was reviewed by the CSA TCIT under the jurisdiction of the Standards Steering Committee on Information Technology and deemed acceptable for use in Canada. (A committee membership list is available on request from the CSA Committee Administrator.) This Standard has been formally approved, without modification, by these Committees and has been approved as a National Standard of Canada by the Standards Council of Canada. February 1995 Notes: (1) Although the intended primary application of this Standard is stated
