V.34	(R+1)*2400, con R: 0-13
V.32bis	14400 - 12000 - 7200 b/s
V.32	9600 – 4800 b/s
V.22bis	2400 b/s
V.22 & Bell 212A	1200 b/s
V.21 & Bell 103	300 b/s

3. Manual de Referencia de los comandos

AT Command set summary for PCTel chipset
 

Table 1. AT Command Set

Command	Function
AT	Attention - this precedes all commands except A/
A/	Execute previous command - does not require a <CR> *
A	Causes the modem to go off hook. If a call is coming in, the modem will try to answer it. The procedure for answering a call is a short silence and then an answer tone. Sending a character to the modem during this procedure will abort the answer procedure. The amount of time the modem will wait for a carrier is programmable by modifying the S7 register.
B0 B1 B2	B0 Select CCITT V.22 (1200 bps) Select Bell 212A (1200 bps) Select CCITT V23 Originate mode will transmit data at 75 bps and receive data at 1200 bps. Answer mode will transmit data at 1200bps and receive data at 75bps. The command N0 (Disable auto mode) must be selected.
D Dmn	D alone will take the modem off-hook and wait for a dial tone. (See X command for exceptions) The length of time to wait for a dialtone before dialing is programmable in register S6. ATDmn will dial a phone number where m is a modifier: L, W, ,, ;, @, !, or S. It will dial the telephone number n.
L	Dial last number
W	Wait for dial tone. If you have selected X0 or X1 (disable dial tone detection), then you can use this modifier to override that setting.
,	Pause during dial. The amount of time to pause is determined in register S8.
;	Return to command mode after dialing. It doesn't wait for carrier or hang up.
@	Wait for 5 seconds of silence. This is used to access systems that do not provide a dial tone.
!	Hook flash. Causes the modem to go on-hook for 0.5 seconds. This is used in PBX systems and for voice features like call waiting
S=(0-9)	Dials a stored number. Up to ten numbers can be stored, and the addresses are from 0 to 9. To store a number into one of these addresses, use the &Z command.
^	Turns on 1300Hz calling tone.
E0 E1	Commands issued to the modem are not echoed to the local terminal. This only matters in the command mode. It does not affect the modems ability to send response codes. Commands are echoed to the local terminal.
H0 H1	Force modem on-hook (hang-up). Force modem off-hook (to answer or dial).
I0 I1 I2 I3 I4	Return numeric product code Return hardware variation code Report internal code Report software revision number Report product feature listing
L0 L1 L2 L3	Speaker volume zero Speaker volume low Speaker volume low Speaker volume low (Hardware currently limits volume adjustment to on/off)
M0 M1 M2 M3	Speaker always off Speaker on until carrier detected Speaker always on Speaker on during answering only
N0 N1	Disable auto-mode. This forces the modem to connect at the speed specified in register S37. Enable auto-mode. The modem will answer at the highest available line speed and ignore any ATBn command.
O0 O1	Return to data mode. If you have entered the command mode using the time independent escape sequence, this will put you back in data mode without going on-hook. Retrain the modem. If the line condition has changed since the original connection, retraining the modem will cause it to reconnect at the most efficient speed for the current line condition.
P	Pulse dialing allows the modem to work on telephone networks where tone is not supported.
Q0 Q1	Enable response to DTE. Disable response to DTE. The modem does not respond to the terminal. Issuing a command will not produce a response (unless the command is something like ATZ, which will restore this setting to default.)
Sn	Set default S-register. Any subsequent = or ? commands will modify the default S register.
Sn=m	Set register n to value m
Sn?	Return the value of register n
T	Tone dialing
V0 V1	Result codes will be sent in numeric form. (See the result code table 3) Result codes will be sent in word form. (See the result code table 3).
W0 W1 W2	Report DTE speed only. After connection, there will be no message about what Error Correction or Data Compression protocol is in use. Report DCE speed, Error Correction/Data Compression protocol, and DTE speed. Report DCE speed only
X0 X1 X2 X3 X4	Send OK, CONNECT, RING, NO CARRIER, ERROR and NO ANSWER. Busy and Dial Tone Detection are disabled.  Send X0 messages and CONNECT speed Send X1 message and NO DIALTONE Send X2 messages except NO DIALTONE, BUSY and RING BACK Send all responses
Y0 Y1	Disable long space disconnect Enable long space disconnect; with error correction, hang up after sending 1.6 second long space; without error correction, hang up after 4 second long space.
Z0 Z1	Reset modem to profile 0  Reset modem to profile 1
=n	Sets the value of the default S register
?	Reports the value stored in the default S register.

 

Table 1. & Ampersand Commands

Command	Function
&C0 &C1	Force DCD on DCD follows remote carrier
&D0 &D1 &D2 &D3	DTR is assumed on DTR drop causes modem back to command mode without disconnecting DTR drop causes modem to hang up DTR drop causes modem to be initialized;&Y determines which profile is loaded.
&F	Load factory profile
&G0 &G1 &G2	Disable guard tone Enable 550Hz guard tone Enable 1800Hz guard tone on answering modem
&K0 &K3 &K4 &K5 &K6	Disable flow control Enable RTS/CTS flow control Enable XON/XOFF flow control Enable transparent software flow control Enable both RTS/CTS and XON/XOFF flow control
&P0 &P1	Make/break pulse dial ratio of 39/61 Make/break pulse dial ratio of 33/67
&S0 &S1	Force DSR on DSR on at the start of handshaking and off after carrier loss
&T0 &T1	Terminate test Start ALB test
&U0 &U1	Enable trellis coding Disable trellis coding
&V0 &V1 &V2	Display active profile Display stored profiles Display stored telephone numbers
&W0 &W1	Save active profile to profile 0 Save active profile to profile 1
&Y0 &Y1	Use profile 0 on powerup Use profile 1 on powerup
&Zn=m	Save telephone number (up to 36 digits) into memory location n (0-9)

 

Table 1. % Percent Commands

Command	Function
%C0 %C1 %C2 %C3	Disable data compression  Enable MNP5 compression Enable V.42bis compression Enable both V.42bis and MNP5
%E0 %E1 %E2 %E3	Disable auto-retrain Enable auto-retrain Enable auto-retrain and fallback Enable auto-retrain and fast hang up
%L	Report received signal level in -dBm
%N0 %N1 %N2 %N3 %N4 %N5 %N6 %N7 %N8 %N9	Dynamic CPU loading disabled Dynamic CPU loading not to exceed 10% Dynamic CPU loading not to exceed 20% Dynamic CPU loading not to exceed 30% Dynamic CPU loading not to exceed 40% Dynamic CPU loading not to exceed 50% Dynamic CPU loading not to exceed 60% Dynamic CPU loading not to exceed 70% Dynamic CPU loading not to exceed 80% Dynamic CPU loading not to exceed 90%
%Q	Report line signal quality

 

Table 1. \ Backslash Commands

Command	Function
\A0 \A1 \A2 \A3	64-character max. MNP block size 128-character max. MNP block size 192-character max. MNP block size  256-character max. MNP block size
\Bn	In non-error correction mode, transmit break in 100 ms units (1-9 with default 3)
\G0 \G1	Disable XON/XOFF flow control (modem to modem) Enable XON/XOFF flow control (modem to modem)
\Kn	Define break type (refer to table 2)
\L0 \L1	Use stream mode for MNP Use interactive block mode for MNP
\N0 \N1 \N2 \N3 \N4 \N5	Normal mode; speed control without error correction Plain mode; no speed control and no error correction Reliable mode Auto-reliable mode LAPM error correction only MNP error correction only

 

Table 1. * Asterisk Commands

Command	Function
*Q0 *Q1	Send the "CONNECT xxxx" result codes to the DTE when an invalid TIES escape sequence is detected after the "OK" response has already been sent Does NOT send the "CONNECT xxxx" result codes to the DTE when an invalid TIES escape sequence is detected after the "OK" response has already been sent

 

Table 2. Break Types

Command	Function
\Kn \K0 \K1 \K2 \K3 \K4 \K5	Local DTE sends break during normal or reliable mode Enter command state; no break to remote Empty data buffers; break to remote Same as \K0 Immediately send break to remote Same as \K0 Send break to remote with TXD data
\Kn \K0 \K1 \K2 \K3 \K4 \K5	Local modem sends break during plain mode Break to remote; and enter command state Same as \K0 Send break to remote Same as \K0 Same as \K2 Same as \K2
\Kn \K0 \K1 \K2 \K3 \K4 \K5	Remote modem sends break during normal mode Empty data buffers; and send break to DTE Same as \K0 Immediately send break to DTE Same as \K2 Send break to DTE with buffered RXD data Same as \K4

 

Table 3. Result Codes

Long Form	Short Form	Description
OK	0	Modem successfully executed a AT command
CONNECT	1	A connection established
RING	2	Modem detected an incoming call
NO CARRIER	3	Modem lost or could not detect a remote carrier signal within the register S7 time
ERROR	4	Modem detected an error in an AT command
CONNECT 1200	5	Connection at 1200 bps
NO DIALTONE	6	Modem did not detect a dial tone within 5 seconds after off-hook
BUSY	7	Modem detected a busy tone
NO ANSWER	8	Modem did not detect 5 seconds of silence when using the @ dial modifier in the dial command
CONNECT 0600	9	Connection at 600 bps
CONNECT 2400	10	Connection at 2400 bps
CONNECT 4800	11	Connection at 4800 bps
CONNECT 9600	12	Connection at 9600 bps
CONNECT 7200	13	Connection at 7200 bps
CONNECT 12000	14	Connection at 12000 bps
CONNECT 14400	15	Connection at 14400 bps
CONNECT 19200	16	Connection at 19200 bps
CONNECT 38400	17	Connection at 38400 bps
CONNECT 57600	18	Connection at 57600 bps
CONNECT 115200	19	Connection at 115200 bps
CONNECT 28800	20	Connection at 28800 bps
CONNECT 300	21	Connection at 300 bps
CONNECT 1200TX/75RX	22	Connection at transmit 1200/receive 75 bps
CONNECT 75TX/1200RX	23	Connection at transmit 75/receive 1200 bps
CONNECT 110	24	Connection at 110 bps
RING BACK	25	Ring Back signal detected
+FCERROR	+F4	Error occured in Class 1 fax operation
FAX	33	Fax modem connection established
DATA	35	Data modem connection established
CARRIER 300	40	Carrier rate of 300 bps
CARRIER 1200/75	44	Carrier rate of transmit 1200/receive 75 bps
CARRIER 75/1200	45	Carrier rate of transmit 75/receive 1200 bps
CARRIER 1200	46	Carrier rate of 1200 bps
CARRIER 2400	47	Carrier rate of 2400 bps
CARRIER 4800	48	Carrier rate of 4800 bps
CARRIER 7200	49	Carrier rate of 7200 bps
CARRIER 9600	50	Carrier rate of 9600 bps
CARRIER 12000	51	Carrier rate of 12000 bps
CARRIER 14400	52	Carrier rate of 14400 bps
CARRIER 16800	53	Carrier rate of 16800 bps
CARRIER 19200	54	Carrier rate of 19200 bps
CARRIER 21600	55	Carrier rate of 21600 bps
CARRIER 24000	56	Carrier rate of 24000 bps
CARRIER 26400	57	Carrier rate of 26400 bps
CARRIER 28800	58	Carrier rate of 28800 bps
CONNECT 16800	59	Connection at 16800 bps
CONNECT 21600	61	Connection at 21600 bps
CONNECT 24000	62	Connection at 24000 bps
CONNECT 26400	63	Connection at 26400 bps
COMPRESSION: CLASS 5	66	MNP Class 5 data compression connection established
COMPRESSION: V.42bis	67	V.42bis data compression connection established
COMPRESSION: NONE	69	Connection established without data compression
PROTOCOL: NONE	76	Connection established without error correction
PROTOCOL: LAPM	77	V.42/LAPM error correction connection established
PROTOCOL: ALT	80	MNP 3-4 error correction connection established

 

Table 4. S-Registers

Register	Function
0	Rings to auto-answer Set the number of rings required before the modem answers. 0 setting disables auto-answer. Range: 0 - 255 rings Default: 0 (auto-answer disabled)
1	Ring counter Count the number of rings before the modem answers. Range: 0 - 255 rings Default: 0
2	Escape character Define the character used for the three-character escape code sequence. 0 setting disables the escape code character. Range: 0 - 127 Default: 43 (+)
3	Carriage return character Define the character for carriage return Range: 0 - 127 Default: 13 (carriage return)
4	Line feed character Define the character for line feed  Range: 0 - 127  Default: 10 (line feed)
5	Backspace character Define the character for backspace Range: 0 - 127 Default: 8 (backspace)
6	Wait before dialing Set the length of time to pause after off hook before dial. Range: 2 - 255 seconds Default: 2 seconds
7	Wait for carrier after dial Set the length of time that the modem waits for a carrier from the remote modem before hanging up. Range: 1 - 255 seconds Default: 50 seconds
8	Pause time for dial delay Set the length of time to pause for the pause dial modifier ",". Range: 0 - 255 seconds Default: 2 seconds
9	Carrier detect response time Define the length of time a signal is detected and qualified as a carrier. Range: 1 - 255 tenths of a second Default: 6 (0.6 second)
10	Lost carrier hang up delay Set the length of time the modem waits before hanging up for a carrier loss. Range: 1 - 255 tenths of a second Default: 14 (6 seconds)
11	DTMF speed control Set the length of tone and the time between tones for the tone dialing. Range: 50 - 255 milliseconds Default: 95 milliseconds
12	Escape Prompt Delay (EPD) timer Set the time from detection of the last character of the three character escape sequence until the "OK" is returned to the DTE Range: 0 - 255 fiftieths of a second Default: 50 (1 second)
13	Reserved
14	Reserved
15	Reserved
16	Reserved
17	Reserved
18	Test timer Set the length of loopback test. Range: 0 - 255 seconds Default: 0 (disable timer)
19	Reserved
20	Reserved
21	Reserved
22	Reserved
23	Reserved
24	Reserved
25	Delay to DTR Set the length of time the modem ignores DTR before hanging up Range: 0 - 255 hundredths of a second Default: 5 (0.05 second)
26	Reserved
27	Reserved
28	Reserved
30	Disconnect inactivity timer set the length of time allowed for inactivity before the connection is hung up. Range: 0-255 in 10 seconds Default: 0 (disabled)
32	XON character Set the value of XON character Range: 0-255 Default: 17
33	XOFF character Set the value of XOFF character Range: 0-255 Default: 19
34	V.34 data rate (bit-rate) Set the maximum bit rate for V.34 Range : 0-8 (2400 baud) 1-10 (3000 baud) 1-11 (3200 baud) 1-13 (3429 baud) bit rate = ((S34)+1) * 2400bps  Default: 13 (33600 bps)
35	V.34 symbol rate (baud-rate) Set the maximum baud rate for V.34 Range: 0-5 0 - 2400 baud 1 - 2743 baud (N/A) 2 - 2800 baud (N/A) 3 - 3000 baud  4 - 3200 baud  5 - 3429 baud (N/A until V.34bis)  Default: 0 (2400 baud)
36	Reserved
37	Line connection speed 0 - Attempt to connect at the highest speed 3 - Attempt to connect at 300 bps 4 - Attempt to connect at 1200 bps 6 - Attempt to connect at 2400 bps 7 - Attempt to connect at 4800 bps 8 - Attempt to connect at 7200 bps 9 - Attempt to connect at 9600 bps 10 - Attempt to connect at 12000 bps 11 - Attempt to connect at 14400 bps 12 - Attempt to connect at V.34 Default: 0
38	Delay before forced hang up Set the delay to hang up after the disconnecting command is received. Range: 0 - 255 seconds Default: 20 seconds
39	Reserved
40	Reserved
41	Reserved
42	Reserved
43	Reserved
44	Reserved
45	Reserved
46	Reserved
47	Reserved
48	Reserved
82	Reserved
86	Call failure reason code 0 - Normal disconnect; no error  4 - Loss of carrier  5 - V.42 negotiation failed to detect an error correction modem at remote end  6 - No response to complete negotiation  9 - No common protocol  12 - Remote initiated a normal disconnect  13 - Remote modem did not respond after 10 message retransmissions  14 - Protocol violation  15 - Compression Failure  20 - Hang up by inactivity time out
91	Transmit level Set the transmit level in -dBm Range: 0 - 15 (-dBm) Default: 11 (-11 dBm)

Country Code Selection and Identification

This command provides the ability of selection the desired country telephony Central Office. When the selection is correct, a set of the selected country parameters will be loaded for the current operation.
 

Country	n
USA	1
France	2
Germany	3
Italy	4
Sweden	5
UK	6
Japan	7
Australia	8
Spain	9
Taiwan	10
Singapore	11
Korea	12
Switzerland	13
Norway	14
Netherlands	15
Belgium	16
Canada	17
Ireland	18
Portugal	19
Poland	20
Hungary	21
Finland	22
Denmark	23
Result Codes: OK If correct selection.  ERROR Otherwise. Command format: AT%I? Result Codes: country name CO ( Central Office)  ERROR Otherwise.