Information Technology Reference
In-Depth Information
Table C.1
Modem return codes
Message
Digit
Description
OK
0
Command executed without errors
CONNECT
1
A connection has been made
RING
2
An incoming call has been detected
NO CARRIER
3
No carrier detected
ERROR
4
Invalid command
CONNECT 1200
5
Connected to a 1200 bps modem
NO DIAL-TONE
6
Dial-tone not detected
BUSY
7
Remote line is busy
NO ANSWER
8
No answer from remote line
CONNECT 600
9
Connected to a 600 bps modem
CONNECT 2400
10
Connected to a 2400 bps modem
CONNECT 4800
11
Connected to a 4800 bps modem
CONNECT 9600
13
Connected to a 9600 bps modem
CONNECT 14400
15
Connected to a 14 400 bps modem
CONNECT 19200
16
Connected to a 19200 bps modem
CONNECT 28400
17
Connected to a 28400 bps modem
CONNECT 38400
18
Connected to a 38400 bps modem
CONNECT 115200
19
Connected to a 115200 bps modem
FAX
33
Connected to a FAX modem in FAX mode
DATA
35
Connected to a data modem in FAX mode
CARRIER 300
40
Connected to V.21 or Bell 103 modem
CARRIER 1200/75
44
Connected to V.23 backward channel carrier modem
CARRIER 75/1200
45
Connected to V.23 forwards channel carrier modem
CARRIER 1200
46
Connected to V.22 or Bell 212 modem
CARRIER 2400
47
Connected to V.22 modem
CARRIER 4800
48
Connected to V.32bis 4800 bps modem
CONNECT 7200
49
Connected to V.32bis 7200 bps modem
CONNECT 9600
50
Connected to V.32bis 9600 bps modem
CONNECT 12000
51
Connected to V.32bis 12000 bps modem
CONNECT 14400
52
Connected to V.32bis 14400 bps modem
CONNECT 19200
61
Connected to a 19 200 bps modem
CONNECT 28800
65
Connected to a 28 800 bps modem
COMPRESSION: CLASS 5
66
Connected to modem with MNP Class 5 compression
COMPRESSION: V.42bis
67
Connected to a V.42bis modem with compression
COMPRESSION: NONE
69
Connection to a modem with no data compression
PROTOCOL: NONE
70
PROTOCOL: LAPM
77
PROTOCOL: ALT
80
C.3 S-registers
The modem contains various status registers called the S-registers which store modem settings. Table C.2 lists these
registers.
S14
Bitmapped options
0
1
Bit 1
E0
E1
Bit 2
Q0
1
Bit 3
V0
V1
Bit 4
Reserved
Bit 5
T
(tone dial)
P (pulse dial)
Bit 6
Reserved
Bit 7
Answer mode
Originate mode
S16
Modem test mode register
0
1
Bit 0
Local analogue loopback
Local analogue loopback
