1、- ITU-T RECMM*S*33 93 4Bb259L 0593773 LO5 INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU TELEGRAPHY ALPHABETICAL TELEGRAPH TERMINAL EQUIPMENT s.33 (03/93) ALPHABETS AND PRESENTATION CHARACTERISTICS FOR THE INTEX SERVICE ITU-T Recommendation S.33 (Previous
2、ly “CCITT Recommendation”) ITU-T RECMN*S.33 93 W 4862593 0593772 041 = FOREWORD The ITU Telecommunication Standardization Sector (IT-T) is a permanent organ of the International Telecom- munication Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Rec
3、ommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTSC), which meets every four years, established the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations on these to
4、pics. IT-T Recommendation S.33 was prepared by the ITU-T Study Group IX (1988-1993) and was approved by the WTSC (Helsinki, March 1-12, 1993). NOTES 1 As a consequence of a reform process within the International Telecommunication Union (ITU), the CCIT ceased to exist as of 28 February 1993. In its
5、place, the ITU Telecommunication Standardization Sector (ITU-T) was created as of 1 March 1993. Similarly, in this reform process, the CCIR and the IFRB have been replaced by the Radiocommunication Sector. In order not to delay publication of this Recommendation, no change has been made in the text
6、to references containing the acronyms “CC, CCIR or IFRB” or their associated entities such as Plenary Assembly, Secretariat, etc. Future editions of this Recommendation will contain the proper terminology related to the new IT structure. 2 telecommunication administration and a recognized operating
7、agency. In this Recommendation, the expression “Administration is used for conciseness to indicate both a O ITU 1994 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 per
8、mission in writing from the ITU. CONTENTS 1 Modes of operation 1.1 Telex interworking mode 1.2 Normal mode 1.3 Extended mode . 1.4 Transparent mode . 2 Character sets and structure 3 Line length . 4 Printing enhancements . 4.2 Bold printing . Changes of operating mode 4.1 Underlining . 5 Recommendat
9、ion S.33 (03/93) Page 1 1 2 2 i Recommendation S.33 ALPHABETS AND PRESENTATION CHARACTERISTICS FOR THE INTEX SERVICE (Helsinki, 1993) The CCITT, considering, (a) that new networks are being introduced based upon stored program control techniques: (b) that these networks as well as being able to cany
10、 the International Telex Service, can also carry the Intex service using alphabets other that International Telegraph Alphabet No. 2 and that interworking between these services is essential; (c) that the Intex service requires the establishment of new types of signalling, and that these signalling
11、types shall permit interworking between Intex terminals, between telex terminals and Intex terminais, and between telex terminals and terminai capable of operating both telex and Intex dual service terminals; (4 Service and the Intex service; that Recommendation U.2 10 defines the network interworki
12、ng requirements between the International Telex (e) Telex Service; that Recommendation S.34 describes Intex terminal requirements to effect interworking with the International (f) that Recommendation S.35 defines the coding of answerbacks for the Intex service; (8) that Recommendation F. 150 defines
13、 the operational and service requirements of the Intex service; (h) Intex service and the International Telex Service; that Recommendation F.82 defines the operational and service requirements for interworking between the NOTE - The development in the future of services similar to Intex may occur. I
14、t may be possible that some of the provisions of this Recommendation should be applied to such services. unanimously declares the view 1 Modes of operation Up to four operating modes are envisaged for terminais connected to the Intex service. These are telex interworking mode, normal mode, extended
15、mode and transparent mode. The choice of the three non-telex modes is a customer option on a call-by-call basis, or within a call. 1.1 Telex interworking mode On calls to and from telex customers, only telex interworking mode shall be used, and an Intex terminal shall not generate mode change reques
16、ts on such calls. Operation in the telex interworking mode is described in Recommendation S.34. An Intex terminal connected to a Type 1 network (see Recommendation U.210) shall always default to the telex interworking mode on any call, incoming or outgoing, unless a Speed Indicator sequence indicati
17、ng connection to another Intex terminal is received from the network at the start of the call as described in Recommendation U.101. An Intex terminal connected to a Type 2 network (see Recommendation U.210) shall switch to “Telex Interworking” mode upon receipt of the Telex Indicator sequence IA5 ch
18、aracter 5/1(Q). Recommendation S.33 (03/93) 1 ITU-T RECMN*S-33 93 4862591 0591775 850 1.2 Normal mode Normal mode is intended for the exchange of basic textual messages on a universal basis, without any pre-arrangement or pre-knowledge between the terminals involved. The character set in this mode s
19、hall comprise a subset of the International Alphabet No. 5 (see Recommendation T.50). An Intex terminal connected to a Type 2 network (see Recommendation U.210) shall always default to normal mode on any call, incoming or outgoing, unless a telex indicator sequence is received from the network at th
20、e start of that call as described in Recommendation U.101. An Intex terminal connected to a Type 1 network (see Recommendation U.210) shall switch to “Normal” mode upon receipt of any valid Speed Indicator sequence as defined in Table 9/. 101. 1.3 Extended mode Extended mode allows for the exchange
21、of messages using the full character set of the Intemational Alphabet No. 5 in accordance with Recommendation T.50. This mode shall only be used when it has been established that it is supported by both terminals, by the exchange of request and response sequences described in 5.2 and 5.3. 1.4 Transp
22、arent mode In this mode the alphabet to be used is defined by the customers involved in the call, subject only to the restriction on character structure detailed in 2.2 and 2.3. This mode shall only be used between terminals which are known to be compatible and after the exchange of request and resp
23、onse sequences described in 5.6 and 5.7. 2 Character sets and structure 2.1 parity bit (all of one unit interval duration) plus a stop signal of not less than one unit interval duration. 2.2 duration) plus a stop signal of not less than one unit interval duration. 2.3 The start bit is binary O; the
24、stop signal is binary 1. The bits are transmitted in the order BI to B7 with the parity bit (where applicable) added before the stop signal. In normal and extended modes parity is even with respect to binary 1. 2.4 In normal and extended modes, each transmitted character shall comprise a start bit,
25、seven information bits, a In transparent mode each transmitted character shall comprise a start bit, eight bits (all one unit interval The character set for normal and extended mode is shown in Table 1. 3 Line length In normal mode an Intex terminal shall be able to print (or display) 80 characters
26、per line. 4 Printing enhancements In normal mode, Intex terminals shall be able to support underlining and bold printing as printing enhancements. Where a message is not printed but displayed on a screen, underlining and bold printing may be replaced by the use of half intensity, inverse video, or o
27、ther video highlighting. 4.1 Underlining 4.1.1 When a transmitting terminal requires subsequent transmitted characters to be underlined it shall transmit the character sequence 1/11, 2/13, 3/1. When a transmitting terminal requires underlining of characters to cease it shall transmit the character 1
28、/11,2/13, 3/0. 4.1.2 When a receiving terminal receives the character sequence 1/11, 2/13, 3/1 it shall underline (or display in video highlight) subsequent received characters. When a receiving terminal receives the character sequence 1/11, 2/13, 3/0 it shall cease underlining (or highlighted displ
29、ay) of received characters. 4.1.3 At the beginning of any incoming or outgoing call an Intex terminal shall default to the non-underlined mode. 2 Recommendation S.33 (03/93) ITU-T RECMNxS.33 93 H 4Bb2593 0593776 797 O O O - B4 O O O 1 1 1 1 O 1 1 O O 1 1 1 O 1 O 1 O 1 O O O O O O O O 1 1 1 1 1 1 1 1
30、 - - B3 O O O O 1 1 1 1 O O O O 1 1 1 1 - - B2 O O 1 1 O O 1 1 O O 1 1 O O 1 1 - - BI O 1 O 1 O 1 O 1 O 1 O 1 O 1 O I - B7 B6 B5 Row O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 TABLE M.33 Character set O NUL (Note 2) SOH (Note 1) STX (Note i) ETX (Note i) EOT (Note 1) ENQ (WRU) ACK (Note i) BELL BS HT (No
31、te i) LF VT (Note 1) FF (Note 1) CR SO (Note i) SI (Note i) 1 DLE (Note i) DCI (Note 3) DC2 (Note i) DC3 (Note 3) DC4 (Note i) NAK (Note 1) SYN (Note i) ETB (Note i) CAN (Note i) EM (Note i) SUB (Note i) ESC (Note 4) FS (Note 1) GS (Note 1) RS (Note 5) US (Note 5) Column 2 3 O 1 2 3 4 5 6 7 8 9 - -
32、? - 4 A B C D E F G H I J K L M N O - 5 P Q R S T U V W X Y Z - - 6 - a b C d e f g h i j k 1 m n O - 7 P 9 r - S t U V W X Y 2 DEL - NOTES 1 These characters shall not be transmitted by an Intex terminal in normal mode (except as detailed in Note 4). If received in normal mode they shall be ignored
33、 (except as detailed in Note 4). 2 This character (NUL, O/O) shall not be transmitted by an Intex terminal in normal mode. It may be generated by telex networks as a call connected signal and when received at the appropriate stage in a call may be interpreted as such. It may also be generated by a n
34、etwork during call clearing. 3 These characters will be used for X-ONIX-OFF flow control in normal and extended modes. An Intex terminal shall cease transmission when a DC3 (113) character is received. Transmission shall recommence when a DCI (VI) character is received. 4 In normal mode this charact
35、er (ESC, 111 1) shall be generated to implement printing enhancements (such as bold print), to request mode changes or to respond to mode change requests, and shall be followed by specific other characters to define the action involved. See clauses 4 and 5. 5 These characters shall not be generated
36、by an Intex terminal in normal mode other than as part of the answerback. On calls to/from telex customers Type 1 networks will convert between these characters and iettedfigure shifts (see Recommendations U.210 and S.35). When received in normal mode by an Intex terminai these characters shall be i
37、gnored. 6 In both normal and extended modes: BELL is a character which causes an audible alarm to be sounded: CR is a carriage return; LF is line feed; BS is back space; SP is space; DEL is delete. 7 8 characters are not transmitted on international calls: In normal mode ENQ (WRU) is the character w
38、hich causes an answerback to be transmitted. In both normal and extended modes in the following characters represent national options. It is recommended that these 2/3,214,4/0, 511 1, 5/12, 5113,5/14, 610,711 i, 7/13 and 7/14 Recommendation S.33 (03/93) 3 ITU-T RECMN*S.33 93 m 48b2593 0593777 623 m
39、4.2 Bold printing 4.2.1 When a transmitting terminal requires subsequent transmitted characters to be bold printed it shall transmit the character sequence 111 1,415. When a transmitting terminal requires bold printing of characters to cease it shall transmit the character sequence 1/11,4/6. 4.2.2 W
40、hen a receiving terminal receives the character sequence 1/11, 4/5, it shall bold print (or display in video highlight) subsequent received characters. When a receiving terminal receives the character sequence 1/11, 4/6, it shall cease bold printing (or highlighted display) of received characters. 4
41、.2.3 mode. At the beginning of any incoming or outgoing call an Intex terminal shall default to the non-bold printed 5 Changes of operating mode 5.1 At the beginning of any incoming or outgoing call an Intex terminal shall default to the normal mode. 5.2 mode request sequence 1/11, 1/0,2/2 halt tran
42、smission and wait for a response. When a transmitting terminal in normal mode is required to enter extended mode it shall transmit the extended If the transmitting terminal detects the extended mode positive response sequence 1/11, 0/6, 2/2, it shall enter the extended mode. If the negative response
43、 sequence 1/11, 1/5, 1/5 is detected the transmitting terminal shall remain in normal mode. If neither response sequence is detected the terminal shall either retransmit the extended mode request sequence or clear the call. 5.3 When a receiving terminal in normal or extended mode receives the extend
44、ed mode request sequence it shall, if it is able to support extended mode, respond by transmitting the positive response sequence 1/11, 0/6, 2/2 and then enter or remain in the extended mode. If the receiving terminal is not able to support extended mode it shall respond by transmitting the negative
45、 response sequence 1/11, 1/5, 1/5 and remain in normal mode. 5.4 normal mode request sequence 1/11, 1/0,2/13, halt transmission and wait for a response. When a transmitting terminal in extended mode is required to restore to normal mode it shall transmit the If the transmitting terminal detects the
46、normal mode positive sequence 1/11, 0/6,2/13 it shall restore to normal mode. If the normal mode positive response sequence is not detected the terminal shall either retransmit the normal mode request sequence or clear the call. 5.5 When a receiving terminal in normal or extended mode receives the n
47、ormal mode request sequence it shall respond by transmitting the normal mode positive response sequence 1/11, Oh, 2/13 and either restore to or remain in normal mode. 5.6 transmit the transparent mode request sequence 1/11, 1/0,2/7, halt transmission and wait for a response. When a transmitting term
48、inal in normal or extended mode is required to enter transparent mode it shall If the transmitting terminal detects the transparent mode positive response sequence 1/11, 0/6, 2/7 it shall enter the transparent mode. If the negative response sequence 1/11, 115, 1/5 is detected the transmitting termin
49、al remain int its current mode. If neither response sequence is detected the terminal shall either retransmit the transparent mode request sequence or clear the call. The option to retransmit the transparent mode request sequence shall only be used if the proposed transparent mode supports the recognition of this sequence and the generation of the appropriate response sequence. 5.7 When a receiving terminal in normal or extended mode receives the transparent mode request sequence it shall, if it is able to support transparent mode, respond by transmitting the transparent mode
