N 6
'
' .
" "
: , '.
1) ' , ;
2) ;
3) ;
4) ';
5) ;
6) ';
7) .
8) ();
9) ' .
ϳ
1.1.
" , " " ".
1.2. , .2 " ", -
1.3. ϳ :
- ;
- ;
- , ;
- hayes- ;
- ;
- ';
- ' RS-232C. 5 . 1.
2. :
2.1. : ', IBM , hayes- , .
2.2. . : Telix.
.
' , ' . , ', () . (terminate) '. ' , , . ' (-). ³ ' .
IBM ' - , , . -, . - . , . .
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' , - (, , '), RS232, , ' -. , . , ' . Telix. MSDOS telix. Telix , '. ' , . ALT-Z. , , . ALT-P, , () . (ALT-E), CHAT (ALT-Y). / ALT-R jAlt-S . . CPS (Char per second) - .
1) , 䳿.
' (, ). ' . - ( "").
3- :
, ' ();
, ' ();
, ' .
300-3400 , 300 . 300 , .
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2) .
, , : , .
2.1) .
(AM) , . , , . AM , .
- , .
2.2) .
FM . , , , , , FSK. (FSK - freguency shift keying - ). , FM AM . '. FSK , .
2.3) - ( - ).
. 4- . , 8 , . 3 .
2.4) - .
- - , , , 48 , 45 . , , 32 , 5 . ҳ, 48 : 548=240 . 9600 / 40 (9600:240); , . - 2240 . .
3) .
CCITT (Comite Consultatie International Telegraphigue et Telephonigue - - ) ̳ ' (ITU - International Telecommunication Union), .
CCITT ' , ; , '.
3.1) .
3.1.1) 200- CCITT V.21 (1964) (BELL 103.113)
V.21 FSK ( ) PSTN 300 . FSK - ; . , - (5,7,8 ) . , . :
, (5) 1,() 1 1180 980 2 1850 1650
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, ', , , -2, .
Bell (! - 1070 = 0 1270 = 1;
2 - 2025 = 0 2225 =1).
3.1.2) 600/1200 CCITT V.23 (1964) (US BELL 202)
FSK, 200 . 1200 4- 2- '. ( - , ).
:
0, (s) 1, (mark)
600 1700 1300
1200 2100 1300
, 75- , FSK. :
0 1
450 390
. . , .
V.23 , , .
Bell 202 V.23 - (2200 = 0; 1200 = 1). ³ , (flow control) - ON/OFF 387 .
3.1.3) 600/1200 / CCITT V.22 (1979) (US Bell 212)
1200 / . ³ , , , 1200 2400 .
㳺, / , / . 5 . г 5- . :
1). 1200 /
2). 1200 / / 8,9,10 11
3). 600 /
4). 600 / / 8,9,10 11
5). 1200 / / 300
1200 / , 4- 2- . 600 . V22:
1200 / | 600 / | 1-4 | 5 | |||
+90 | +270 | |||||
- | + 180 | |||||
+ 270 | + 90 | |||||
- | + 180 | |||||
' , , , ..: | ||||||
, | ||||||
1200 | 2400 | |||||
, | 2400 | 1200 | ||||
2400 1800 , .
V.22 bis (bis - ). 쳺 2400 / ' .
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3.1.4) 1200/2400 / CCITT V.26(1968) V.26bis(1972) VS Bell 201
, 1800 2400 /, 2- , 1200 /. 1200 .
V.26 2400 / 4- . V.26 bis 2400 / ' PSTN ( 4- ) (fallback) 1200 /.
(75 /) , FSK CCITT V.23. 24QO / , :
+45 | ||
+ 90 | + 135 | |
+ 180 | +225 | |
+270 | +315 |
, . PSTN. 1200 / :
- 0 +90
- 1 +270
V.26 bis, , . .
3.1.5) 4800 / CCITT V.27 (1972) V.27 bis. V.27 ter (1976) US Bell 208B
V.27 V.27 bis 4800 /, 4- . V.27 bis 2400 /. ', V.27 ter (ter - , ), ; 4800 / 2400 /. 4800 /, 8 , 3- . 1800 , 1600 .
3.2) .
, 3000 . V.21 300 /, 1/5 . V.22 1200 / , 600 2 . V.22bis 2400 / , - - (QAM).B 4 . 1200 /, 2400 / 600 .
2400 / 9600 / , . , 1200 / 2400 / . . 4800 / (1200 ) / . 9600 / 90% , .
3 9600/: , ' ':
3.2.1) .
. , . , (DSP). 9600 / .
V.32.
CCITT V.32 9600 /, 1984 , . DSP (digital signal processor), . V.32 4800 /. V.32 ("trellis-coded" modulation). TCM , .
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V.32bis.
1989 . ³ V.32, 14400 /, 12000, 9600, 7200, 4800 / . . - V.32bis ' . , V.32bis, . ' , V.32bis .
V.17.
CCITT 1991 . . , V.32bis, V.32bis 12000 14400 /. 7200 9600 V.29 .
V.FAST.
CCITT 1994 . - V.32bis. - ' 28800 /. , , . '.
3.2.2) '.
9600 / . - - . , ( BBS), (, ). , . , , , . , .
V.29.
CCITT V.29 (1976) 9600 / 7200 4800 / . ³ Group III. V.29 - . Microcom MNP5 MNP6, ' . . 8 . 8- , 4 . 9600:4=2400 . , 1700 .
4 (), , , . , , .
PEP.
Telebit, PEP (Packetized Ensemble Protocol), DAMQAM ( - ). 511 , , 2, 4 6 1 , . ϳ ' 400 , - . , 18031 /. 20% - 14400 /.
PEP 3 :
) , . "spoofing". To ', , .
) PEP'a "" , ("phase jitter"). , "" , , PEP .
) PEP'a , .
3.2.3) '.
, , . 100 / 100 . , - , . 9600 / 300 / , . , . - - ' . , - . HST.
Գ US Robotics ' HST (High Speed Technology). HST - 9600 /, V32 ( ), 300 /. , . , , . 4 , . , , . , .
haves-
4.1) Hayes'a
AT ( At, aT, at) <CR>. , . , , ' (). .
, <CR> . . ' , , .: AT DT 8W (044) 430-49-00, ATDP8W0444304900.
40 , AT. , 40 , ERROR . <Backspace>. . ( ). - .
ϳ ( ) .
4.2)
AT - () .
ϳ .
- .
, .
ϳ , 䳺 .
', , . (auto-answer) (S0=0) , ' .
/ - .
(AT) <CR>.
Bn - :
n = CCITT V.21, V.22, V.22 bis
n = 1 BELL 103/202A.
DP - .
ϳ , ' .
, , ( ).
En - ON/OFF.
ϳ 1 , , . 0 .
n = 0
n = 1
n - .
':
n = 0
n = 1 .
In - :
n = 0
n = 1 ROM (EPROM), n = 2 ' ROM ERROR.
Ln - ().
n = 0,1
n = 2
n = 3
- (). = 0
n = 1 ,
n = 2
n = 3 , , .
Qn - .
n = 0
n = 1 .
Q0 Q1 S-, , ( S, I, & ).
- , CONNECT ( ).
Sr - S-.
Sr? - S- r.
Sr=nnn - nnn S- r.
- S-. S- , S.
Vn - .
n = 0
n = 1 .
³ | ³ | |
CONNECT | 300 bps 0 600, 1200, 2400 bps. | |
RING | . ³ , . | |
NO CARRIER | , . | |
ERROR | . 40 , ( L2). | |
CONNECT 1200 | 1200 bps ( XI, 2, , 4). | |
NO DIALTONE | ³ ( 2, 4). | |
BUSY | () . | |
NO ANSWER | ³ - 5s (. D). | |
CONNECT 600 | 600 bps ( XI, 2, , 4). | |
CONNECT 2400 | 2400 bps ( XI, 2, , 4). |
Xn - ' :
0 | X1 | 2 | 3 | 4 | |
' | |||||
(S6 s) | |||||
"" |
' 1 - , ' CONNECT, .
' 2 - , ' : CONNECT, CONNECT 600, CONNECT 1200 CONNECT 2400. ³ CONNECT 300 bps.
(S6 s) - , , S- S6 .
- , 5s NO DIALTONE .
"" - , , , BUSY, .
Yn - .
:
- , DTR
- 0 , 4 s.
n = 0 (. &D)
n = 1 .
Z - ( ' NOVRAM).
&Cn - DCD.
n = 0 DCD
n = 1 DCD , , .
&Ln - '.
n = 0 '
n = 1 '.
&W - ' RAM ' NOVRAM. S- ' NOVRAM.
&Z - ' NOVRAM( 33 ).
4.3) S-.
S0 - ʳ , : (0-255) SO = 0
S6 -
ij: 2 - 255
: 002 s
S7 - ,
ij: 1 - 155
: 030 s
S8 -
ij: 0 - 255
: 002 s
S9 - DCD
ij: 0 - 255
: 005 (xl/10s = 0,6s)
DCD , .
S10 - ' ,
ij: 1 - 255
: 014 (xl/lOs = 1,4s)