1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 3 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%2!0(9!,0(!“%4)#!,G0G04%,%2!0(G0G04%2-).!,%15)0-%.434!.$!2$):!4)/.G0G0/ amended at Geneva, 1976)The CCITT,considering(a) that the basic model page-printing machine is defined as having certain basic featur
2、es for receiving(including printing) and/or transmitting;(b) Recommendations T.50 1, V.4 2 and X.4 3,unanimously declares the view1 The sets of graphics to be used should be either: a set of 95 characters consisting of columns 2 to 7 in the code table of International Alphabet No. 5excluding the cha
3、racter DEL; or a smaller set of 64 characters consisting of columns 2 to 5 of the code table International Alphabet No. 5.If the machine is designed only for the smaller set of characters, the logic of the machine must be such that theprints the appropriate capital letters even when it receives a co
4、de combination for small letters.Note The interpretation, by 64-character machines, of other than alphabetic charactes in columns 6 and 7 ofthe code table is at the discretion of Administration for the time being.2 The number of characters that the line of text of the basic model page-printing machi
5、ne may contain should befixed at 80.3 To ensure the new-line function on direct printing machines: the transmitter must send at least n characters; the receiver must operate correctly on receipt of n characters.For speeds up to and including 20 characters per second, n = 4. At 27.3 (corresponding to
6、 300 bauds) and30 characters per second, n = 6. The n characters consist of: one format effector CR (position 0/13 in International Alphabet No. 5); one formet effector LF (position 0/10 in International Alphabet No. 5); the appropriate remaining number of non-printing and non-carriage moving charac
7、ters (but the CRcharacter is allowed);4 The time elapsing between the application of power to the motor of a machine and the machines running up tospeed and being ready to receive or send characters should not exceed 600 ms. Where the machine is used in aswitched network, this elapsed time shall sta
8、rt form the instant when an incoming call is received at the interface.Note Manufacturers should endeavour to minimize this time.References1 CCITT Recommendation International Alphabet No. 5, Rec. T.50.2 CCITT Recommendation General structure of signals of International Alphabet No. 5 code for datatransmission over public telephone networks, Rec. V.4.3 CCITT Recommendation General structure of signals of International Alphabet No. 5 code for datatransmission over public data networks, Rec. X.4.
