The modem will respond to the commands detailed below. Parameters applicable to each command are listed with the command description. The defaults shown for each configuration command are those used in the factory profile 0.
A/ Re-execute command. The modem behaves as though the last command line had been re-sent by the DTE. ‘A/’ will repeat all the commands in the command buffer. The principle application of this command is to place another call. Note: This command should not be terminated by a carriage return.
AT A Answer. The modem will go off-hook and attempt to answer an incoming call.
AT B0 Selects CCITT operation at 300 or 1200bps during Call Establishment and a subsequent connection (default). Any other line speed will use a CCITT modulation standard.
AT B1 Selects BELL operation at 300 or 1200bps during Call Establishment and a subsequent connection. The parameter value, if valid, is written to S27 bit 6. (Also, see +MS command.)
AT C1 Carrier control. This command is ignored. Returns OK.
AT D Dial. This command directs the modem to go off-hook, dial according to the string entered and attempt to establish a connection. If no dial string is supplied, the modem will go off-hook and attempt the handshake in originate mode. Possible parameters are:
0-9 Tone and pulse dial digits 0 to 9.
* The 'star' digit (tone dialling only)
# The 'gate' digit (tone dialling only).
A-D DTMF digits A, B, C, D.
J Perform MNP 10 link negotiation at 1200bps (for this call only). (See *H.)
K Enable power level adjustment during MNP 10 link negotiation (for this call only).
L Re-dial last number: the modem will re-dial the last valid telephone number. The L must be immediately after the D with all the following characters ignored.
P Select pulse dialling: pulse dial the numbers that follow until a ‘T’ is encountered. Affects current and subsequent dialling. Note: Some countries prevent changing dialling modes after the first digit is dialled.
T Select tone dialling: tone dial the numbers that follow until a ‘P’ is encountered. Affects current and subsequent dialling. Note: Some countries prevent changing dialling modes after the first digit is dialled.
R This command will be accepted, but not acted on.
S=n Dial the number stored in the directory (n = 0 to 3). (See &Z.)
! Flash: the modem will go on-hook for a time defined by the value of S29. Country requirements may limit the time imposed.
W Wait for dial tone: the modem will wait for dial tone before dialling the digits following ‘W’. If no dial tone is detected within the time specified by S6, the modem will abort the rest of the sequence, return on-hook, and generate an error message. The modem will handshake.
@ Wait for silence: the modem will wait for at least 5 seconds of silence in the call progress frequency band before continuing with the next dial string parameter. If the modem does not detect these 5 seconds of silence before the expiration of the call abort timer (S7), the modem will terminate the call attempt with a NO ANSWER message. If busy detection is enabled, the modem may terminate the call with the BUSY result code. If answer tone arrives during execution of this parameter, the modem handshakes.
&Wait for credit card dialling tone before continuing with the dial string. If the tone is not detected within the time specified by S7 (US models) or S6 (W-class models), the modem will abort the rest of the sequence, return on-hook, and generate an error message.
, Dial pause: the modem will pause for a time specified by S8 before dialling the digits following .
; Return to command state. Added to the end of a dial string, this causes the modem to return to the command state after it processes the portion of the dial string preceding the ";". This allows the user to issue additional AT commands while remaining off-hook. The additional AT commands may be placed in the original command line following the ";" and/or may be entered on subsequent lines. The modem will enter call progress only after an additional dial command is issued with the ";" terminator. Use "H" to abort the dial in progress, and go back on-hook.
^ Disable calling tone: applicable to current dial attempt only.
( ) - <space> Ignored: may be used to format the dial string.
<i> Invalid character: will be ignored.
> Ignored: not implemented.
AT E0 Disables command echo of characters to computer.
AT E1 Enables command echo (default). The parameter value, if valid, is written to S14 bit 1.
AT H Disconnect (Hang-Up).This command initiates a Hang-Up sequence.
AT H1 If on-hook, the modem will go off-hook and enter command mode. The modem will return on-hook after a period of time determined by S7.
AT I0 Reports product code.
AT I1 Reports pre-computed checksum from ROM.
AT I2 Computes checksum and compares it with value stored in ROM. Reports result as OK or ERROR.
AT I3 Reports firmware revision.
AT I4 Reports additional product identification.
AT I5 Reports Country Code parameter.
AT I6 Reports additional product identification.
AT L0 Low volume.
AT L1 Low volume.
AT L2 Medium volume (default).
AT L3 High volume. The parameter value, if valid, is written to S22 bits 0 and 1.
AT M0 Speaker is always off.
AT M1 Speaker is on during call establishment, but off when receiving carrier (default).
AT M2 Speaker is always on.
AT M3 Speaker is off when receiving carrier and during dialling, but on during answering. The parameter value, if valid, is written to S22 bits 2 and 3.
AT N0 Automode detection is disabled. A subsequent handshake will be conducted according to the contents of S37 or, if S37 is zero, according to the most recently sensed DTE speed.
AT N1 Automode detection is enabled. A subsequent handshake will be conducted according to the Automode algorithm supported by the modem. This command is equivalent to +MS<Automode> (default). The parameter value, if valid, is written to S31 bit 1.
AT O0 Enters On Line data mode without a retrain. Handling is determined by the Call Establishment task. Generally, if a connection exists, this command connects the DTE back to the remote modem after an escape (+++).
AT O1 Enters On Line data mode with a retrain before returning to On Line data mode.
AT P Set pulse dial default. Sets S14 bit 5.
AT Q Quiet results codes control.
AT Q0 Enables result codes to the DTE (default).
AT Q1 Disables result codes to the DTE.
AT Q2 Disables result codes in answer mode. The parameter value, if valid, is written to S14.
AT Sn Establishes S-register n as the default register.
AT Sn=v Write the value V to S-register number n. This command writes the value v to the currently selected S-register. All of the S-registers will return the OK response if v is a number. Ex. AT S0=1 Enables auto answer from S0 after 1 incoming ring.
AT Sn? Reports the value of S-register n. If the number "n" is beyond the range of the S-registers available, the modem will return the ERROR message. Input and output are always in decimal format. In some cases, writing to the S register will appear to be accepted but the value will not actually be written.
Note: Due to country restrictions, some commands will be accepted, but the value may be limited and replaced by a maximum or minimum value.
AT T Set tone dial default. This command forces DTMF dialling until the next P dial modifier or P command is received. The DP command will override this command. Clears S14 bit 5. This command may not be permitted in some countries (see P).
AT V0 Enables short-form (terse) result codes. Line feed is not issued before a short-form result code.
AT V1 Enables long-form (verbose) result codes (default). The parameter, if valid, is written to S14 bit 3.
AT W0 Upon connection, the modem reports only the DTE speed (e.g. CONNECT 57600). Subsequent responses are disabled.
AT W1 Upon connection, the modem reports the line speed, the error correction protocol, and the DTE speed, respectively. Subsequent responses are disabled (default).
AT W2 Upon connection, the modem reports the DCE speed (e.g. CONNECT 14400). Subsequent responses are disabled. The parameter value, if valid, is written to S31 bits 2 and 3.
AT X Extended result codes. This command selects which subset of the result messages will be used by the modem to inform the DTE of the results of commands.
Blind dialling is enabled or disabled by country parameters. If the user wishes to enforce dial tone detection, a "W" can be placed in the dial string (see D command).Table 3-1 indicates the messages which are enabled for each X value. If the modem is in facsimile mode (+FCLASS=1), the only message sent to indicate a connection is CONNECT without a speed indication.
AT X0 Disables monitoring of busy tones unless forced otherwise by country requirements; send only OK, CONNECT, RING, NO CARRIER, ERROR, and NO ANSWER result codes. Blind dialling enabled/disabled by country parameters. If busy tone detection is enforced and busy tone is detected, NO CARRIER will be reported. If dial tone detection is enforced or selected and dial tone is not detected, NO CARRIER will be reported instead of NO DIAL TONE. The value 000b is written to S22 bits 6, 5, and 4, respectively.
AT X1 Disables monitoring of busy tones unless forced otherwise by country requirements; send only OK, CONNECT, RING, NO CARRIER, ERROR, NO ANSWER, and CONNECT XXXX (XXXX = rate). Blind dialling enabled/disabled by country parameters. If busy tone detection is enforced and busy tone is detected, NO CARRIER will be reported instead of BUSY. If dial tone detection is enforced or selected and dial one is not detected, NO CARRIER will be reported instead of NO DIAL TONE. The value 100b is written to S22 bits 6, 5, and 4, respectively.
AT X2 Disables monitoring of busy tones unless forced otherwise by country requirements; send only OK, CONNECT, RING, NO CARRIER, ERROR, NO DIALTONE, NO ANSWER, and CONNECT XXXX. If busy tone detection is enforced and busy tone is detected, NO CARRIER will be reported instead of BUSY. If dial tone detection is enforced or selected and dial tone is not detected, NO CARRIER will be reported instead of NO DIAL TONE. The value 101b is written to S22 bits 6, 5, and 4, respectively.
AT X3 Enables monitoring of busy tones; send only OK, CONNECT, RING, NO CARRIER, ERROR, NO DIALTONE, NO ANSWER, and CONNECT XXXX. Blind dialling enabled/disabled by country parameters. If dial tone detection is enforced and dial tone is not detected, NO CARRIER will be reported. The value 110b is written to S22 bits 6, 5, and 4, respectively.
AT X4 Enables monitoring of busy tones; send all messages. The value 111b is written to S22 bits 6, 5, and 4, respectively (default).
Note: It is not allowed to use the commands ATX0, ATX1 and ATX2 and the comma dial modifier in Sweden. Some commands may not be available or may be restricted due to national PTT restrictions.
AT Y0 Disables long space disconnect (default).
AT Y1 Enables long space disconnect. In non-error correction mode, the modem will send a long space of four seconds prior to going on-hook. In error correction mode, the modem will respond to the receipt of a long space (i.e. a break signal greater than 1.6 seconds) by going on-hook.
The parameter value, if valid, is written to S21 bit 7.
AT Z0 Soft reset and restore stored profile 0.
AT Z1 Soft reset and restore stored profile 1.
AT \A Select maximum MNP block size. The modem will operate a MNP error corrected link using a maximum block size controlled by the parameter supplied. For MNP10 the parameter indicates at which packet size the modem shall fall forward to a higher speed. The parameter value, if valid, is written to S40 bits 6 and 7.
AT \A0 64 characters.
AT \A1 128 characters.
AT \A2 192 characters.
AT \A3 256 characters (default).
AT \B Transmit break to remote. In non-error correction mode, the modem will transmit a break signal to the remote modem with a length in multiples of 100 ms according to parameter specified. If a number in excess of 9 is entered, 9 is used. The command works in conjunction with the \K command.
In error correction mode, the modem will signal a break through the active error correction protocol, giving no indication of the length.
AT \B1 - AT \B9 Break length in 100 ms units. (default = 3) (Non-error corrected mode only).
AT \G Modem-to-modem flow control (XON/XOFF). In non-error correction mode, the modem enables or disables the generation or recognition of modem-to-modem XON/XOFF flow control according to the parameter supplied. The parameter value, if valid, is written to S41 bit 3.
In error correction mode, the setting of modem-to-modem XON/XOFF flow control is ignored. However, the serial port flow control settings (AT&K) remain active during a reliable link. Due to the buffering system used in the modem, modem-to-modem flow control is normally disabled.
AT \G0 Disables modem-to-modem XON/XOFF flow control (default).
AT \G1 Enables modem-to-modem XON/XOFF flow control.
AT \J Enables DTE autorate adjustment. Controls whether the modem will adjust the DTE speed to match the line speed, when the connections is complete. The parameter value, if valid, is written to S41 bit 5.
AT \J0 Disable adjustment of DTE speed to match line speed.
AT \J1 Enable adjustment of DTE speed to match line speed.
AT \K Break control. Controls the response of the modem to a break received from the DTE or the remote modem or the \B command according to the parameter supplied. The parameter value, if valid, is written to S40 bits 3, 4, and 5. The response is different in three separate states. The first case is where the modem receives a break from the DTE when the modem is operating in data transfer mode: The parameter value, if valid, is written to S41 bit 5.
AT \K0 Enter On Line command mode, no break sent to the remote modem.
AT \K1 Clear data buffers and send break to remote modem.
AT \K2 Same as 0.
AT \K3 Send break to remote modem immediately.
AT \K4 Same as 0.
AT \K5 Send break to remote modem in sequence with transmitted data (default).
The second case is where the modem is in the On Line command state (waiting for AT commands) during a data connection, and the \B is received in order to send a break to the remote modem:
AT \K0 Clear data buffers and send break to remote modem.
AT \K1 Clear data buffers and send break to remote modem (same as 0).
AT \K2 Send break to remote modem immediately.
AT \K3 Send break to remote modem immediately (same as 2).
AT \K4 Send break to remote modem in sequence with data.
AT \K5 Send break to remote modem in sequence with data (same as 4) (default). The third case is where a break is received from a remote modem during a non-error corrected connection:
AT \K0 Clears data buffers and sends break to the DTE.
AT \K1 Clears data buffers and sends break to the DTE (same as 0).
AT \K2 Send a break immediately to DTE.
AT \K3 Send a break immediately to DTE (same as 2).
AT \K4 Send a break in sequence with received data to DTE.
AT \K5 Send a break in sequence with received data to DTE (same as 4) (default). Note: That when S82 is modified, the modem converts the Hayes specific value to the \K format and updates S40 to match. The parameter value, if valid, is written to S41 bit 4.
AT \L MNP block/stream mode select. At connection time, this command controls the selection between block and stream modes of operation in MNP. The parameter value, if valid, is written to S41 bit 4.
AT \L0 Use stream mode for MNP connection (default).
AT \L1 Use interactive block mode for MNP connection. This command will accept block mode but implement stream mode.
AT \N Operating mode. This command controls the preferred error correcting mode to be negotiated in a subsequent data connection.
AT \N0 Selects normal speed buffered mode (disables error-correction mode) (Forces &Q6).
AT \N1 Selects direct mode and is equivalent to &M0, &Q0 mode of operation (Forces &Q0).
AT \N2 Selects reliable (error-correction) mode. The modem will first attempt a LAPM connection and then an MNP connection. Failure to make a reliable connection results in the modem hanging up (Forces &Q5, S36=4, and S48=7).
AT \N3 Selects auto reliable mode. This operates the same as \N2 except failure to make a reliable connection results in the modem falling back to the speed buffered normal mode (Forces &Q5, S36=7, and S48=7).
AT \N4 Selects LAPM error-correction mode. Failure to make an LAPM error correction connection results in the modem hanging up (Forces &Q5 and S48=0). Note: The -K1 command can override the \N4 command.
AT \N5 Selects MNP error-correction mode. Failure to make an MNP error correction connection results in the modem hanging up (Forces &Q5, S36=4, and S48=128).
AT \V Connect messages controlled by the command settings X, W, S95.
AT \V1 Connect messages will be in single line format. CONNECT <DTE speed > <modulation> <protocol> <compression> <Line Speed>.
AT &C0 DCD remains ON at all times.
AT &C1 DCD follows the state of the carrier (default). The parameter value, if valid, is written to S21 bits 3 and 4.
AT &D0DTR_ drop is interpreted according to the current &Q setting as follows:
&Q0, &Q5, &Q6 DTR is ignored (assumed ON). Allows operation with DTEs which do not provide DTR.
&Q1, &Q4 DTR drop causes the modem to hang up. Auto-answer is not affected.
&Q2, &Q3 DTR drop causes the modem to hang up. Auto-answer is inhibited.
AT &D1 DTR drop is interpreted according to the current &Q setting as follows:
&Q0, &Q1, &Q4, &Q5, &Q6
DTR drop is interpreted by the modem as if the asynchronous escape sequence had been entered. The modem returns to asynchronous command state without disconnecting.
&Q2, &Q3 DTR drop causes the modem to hang up. Auto-answer is inhibited.
AT &D2 DTR drop is interpreted according to the current &Q setting as follows:
&Q0 through &Q6 DTR drop causes the modem to hang up. Auto-answer is inhibited (default).
AT &D3 DTR drop is interpreted according to the current &Q setting as follows:
&Q0, &Q1, &Q4, &Q5, &Q6
DTR drop causes the modem to perform a soft reset as if the Z command were received. The &Y setting determines which profile is loaded.
&Q2, &Q3 DTR drop causes the modem to hang up. Auto-answer is inhibited.
If &Q5, &Q6, +FCLASS=1 is in effect, the action taken is the same as for &Q0.
AT &F Restore factory configuration (profile). The modem loads the factory default configuration profile according to the parameter supplied. The factory defaults for profile 0 (&F0) are quoted for each command and in the S register descriptions. Two profiles are available. A configuration profile consists of a subset of S-registers.
AT &F0 Recall factory profile 0 (default).
AT &F1 Recall factory profile 1.
AT &G Select guard tone. The modem generates the guard tone selected by this command according to the parameter supplied (DPSK modulation modes only). The parameter value, if valid, is written to S23 bits 6 and 7.
AT &G0 Disables guard tone.
AT &G1 Enables guard tone.
AT &G2 Selects 1800 Hz guard tone V.22/V.22bis (default). Note: This command may not be permitted in some countries.
AT &J Telephone jack control. This command is only included for compatibility and performs no function except to load the S-register. The parameter value, if valid, is written S21 bit 1. (J0 is default).
AT &K Flow control. This command defines the DTE/DCE (terminal/modem) flow control mechanism. The parameter value, if valid, is written to S39 bits 0, 1, and 2.
AT &K0 Disables flow control.
AT &K3 Enables RTS/CTS flow control (default for data modem modes).
AT &K4 Enables XON/XOFF flow control.
AT &K5 Supports transparent XON/XOFF flow control. Note: Enables both RTS/CTS and XON/XOFF flow control. (default for fax modem voice modes).
AT &M0 Selects direct asynchronous operation. Note: That the command sequence &M0\N0 selects normal buffered mode, but the command sequence \N0&M0 selects direct mode. This is because the \N0 command is analogous to the &Q6 command. The value 000b is written to S27 bits 3, 1, and 0, respectively (see &Q).
AT &P Select pulse dial make/break ratio. This command determines the make/break ratio used during pulse dialling. This command may not be permitted in some countries. The parameter value, if valid, is written to S28 bits 3 and 4.
AT &P0 Selects 39%-61% make/break ratio at 10 pulses per second.
AT &P1 Selects 33%-67% make/break ratio at 10 pulses per second.
AT &P2 Selects 39%-61% make/break ratio at 20 pulses per second.
AT &P3 Selects 33%-67% make/break ratio at 20 pulses per second.
AT &Q This command is an extension of the &M command and is used to control the connection modes permitted. It is used in conjunction with S36 and S48. (Also, see \N.)
AT &Q0 Selects direct asynchronous operation. See &M0.
AT &Q5 The modem will try to negotiate an error-corrected link. The modem can be configured using S36 to determine whether a failure will result in the modem returning on-hook or will result in fallback to an asynchronous connection. The value 101b is written to S27 bits 3, 1, and 0, respectively (default).
AT &Q6 Selects asynchronous operation in normal mode (speed buffering). The value 110b is written to S27 bits 3, 1, and 0, respectively.
AT &R RTS/CTS Option. This selects how the modem controls CTS. CTS operation is modified if hardware flow control is selected (see &K command). The parameter value, if valid, is written to S21 bit 2.
AT &R0 In sync mode, CTS tracks the state of RTS; the RTS-to-CTS delay is defined by S26. In async mode, CTS is normally ON and will turn OFF only if required by flow control.
AT &R1 In sync mode, CTS is always ON (RTS transitions are ignored). tracks the state of RTS; In async mode, CTS is normally ON and will turn OFF only if required by flow control.
AT &S0 DSR will remain ON at all times.
AT &S1 DSR will become active after answer tone has been detected and inactive after the carrier has been lost (default). The parameter value, if valid, is written to S21 bit 6.
AT &T Test and diagnostics. The modem will perform selected test and diagnostic functions according to the parameter supplied. A test can be run only when in an asynchronous operation in non-error-correction mode (normal or direct mode). To terminate a test in progress, the escape sequence must be entered first, except for parameters 7 and 8. If S18 is non-zero, a test will terminate automatically after the time specified by S18 and display the OK message. Test commands may not be available in some countries due to PTT restrictions.
AT &T0 Terminates test in progress. Clears S16.
AT &T1 Initiates local analogue loopback, V.54 Loop 3. Sets S16 bit 0. If a connection exists when this command is issued, the modem hangs up. The CONNECT XXXX message is displayed upon the start of the test.
AT &V Display current configuration and stored profiles. Reports the current (active) configuration, the stored (user) profiles, and the four stored telephone numbers.
AT&V1 Display status of the current or last connection. Min. - max. speed, receive level, line quality, protocol and disconnect cause.
AT &W0 Store the current configuration as profile 0.
AT &W1 Store the current configuration as profile 1.
AT &X Select Synchronous Clock Source. Selects the source of the transmit clock for the synchronous mode of operation. The parameter value, if valid, is written to S27 bits 4 and 5.
AT &X0 Selects internal timing. The modem generates the transmit clock signal and applies it to the TXCLK output at the serial interface.
AT &X1 Selects external timing. The local DTE sources the transmit clock signal on the XTCLK input of the serial interface. The modem applies this clock to the TXCLK output at the serial interface.
AT &X2 Selects slave receive timing. The modem derives the transmit clock signal from the incoming carrier and applies it to the TXCLK output at the serial interface.
AT &Y0 Selects user profile 0 at power up.
AT &Y1 Selects user profile 1 at power up.
AT&Zn=x Store telephone number. The modem can store up to 4 telephone numbers. Each telephone number dial string can contain up to 31 digits.
n=0 to 3 and x = dial string.
AT %C Enable/disable data compression. Enables or disables data compression negotiation. The modem can only perform data compression on an error corrected link. The parameter value, if valid, is written to S41 bits 0 and 1.
AT %C0 Disables data compression. Resets S46 bit 1.
AT %C1 Enables MNP 5 data compression negotiation. Resets S46 bit 1.
AT %C2 Enables V.42 bis data compression. Sets S46 bit 1.
AT %C3 Enables both V.42 bis and MNP 5 data compression. Sets S46 bit 1 (default).
AT %E Enable/disable line quality monitor and auto-retrain or fallback/fall forward. Controls whether or not the modem will automatically monitor the line quality and request a retrain (%E1) or fall back when line quality is insufficient or fall forward when line quality is sufficient (%E2). Applies to dial-up line only. The parameter value, if valid, is written to S41 bits 2 and 6. If enabled, the modem attempts to retrain for a maximum of 30 seconds. Fallback/Fall Forward. When %E2 is active, the modem monitors the line quality (EQM). When line quality is insufficient, the modem will initiate a rate renegotiation to a lower speed within the V.34/V.FC,V.32bis/V.32 modulation speeds. The modem will keep falling back within the current modulation if necessary until the speed reaches 2400bps (V.34), 14400bps (V.FC), or 4800bps (V.32).
Below this rate, the modem will only do retrains if EQM thresholds are exceeded. If the EQM is sufficient for at least one minute, the modem will initiate a rate renegotiation to a higher speed within the current modulation speeds. The rate renegotiations will be done without a retrain if a V.32bis connection is established. Speeds attempted during fallback/fall forward are those shown to be available in the rate sequences exchanged during the initial connection. Fallback/fall forward is available in error correction and normal modes, but not in direct mode or synchronous mode with external clocks.
AT %E0 Disable line quality monitor and auto-retrain.
AT %E1 Enable line quality monitor and auto-retrain.
AT %E2 Enable line quality monitor and fallback/fall forward. (Default.)
AT %L Line signal level. Returns a value which indicates the received signal level. The value returned is a direct indication (line interface dependent) of the receive level internally in the modem, not at the telephone line connector. For example, 009 = -9 dBm, 043 = -43 dBm, and so on.
AT %M0 Command ignored returns an "OK".
AT %M1 Command ignored returns an "OK".
AT %Q Line signal quality. Reports the line signal quality (line interface). Returns the higher order byte of the EQM value. Based on the EQM value, retrain or fallback/fall forward may be initiated if enabled by %E1 or %E2.
AT %U Select µ-Law or A-Law Codec Type. This command selects µ-Law or A-Law codec type for V.90 and K56flex modulation. This command also stores the selected setting directly to NVRAM. The default value is country specific.
AT %U0 Selects µ-law
AT %U1 Selects -law
AT *B Display blacklisted numbers. This command requests the modem to return a list of blacklisted numbers to the DTE. If no numbers are blacklisted, only the OK result code is issued.
AT *C0 Disable call back.
AT *C1 Enable call back. Call back delay is specified by S203.
AT *D Display delayed numbers. This command causes the modem to send a list of the delayed numbers together with the delay associated with each. (delay times are shown hours:minutes:seconds). If no numbers are delayed, only the OK result code is issued.
AT *H Link negotiation speed. This command controls the connection speed for link negotiations before upshift occurs between two MNP Class 10 modems. The parameter value, if valid, is written to S40 bit 2.
AT *H0 Link negotiation occurs at the highest supported speed (default).
AT *H1 Link negotiation occurs at 1200bps.
AT *H2 Link negotiation occurs at 4800bps.
AT *K0 Enable key abort (default).
AT *K1 Disable key abort. The value is written to S21 bit 1.
AT *L Display call back directory.
AT *P Store call-back password. This command causes the modem to store a password and to store or delete a corresponding telephone number in NVRAM. The password will be used to match that supplied by a remote modem when secure access is used. The modem will use the telephone number to dial back the remote modem. The password must be between 6 and 12 characters in length. The telephone number length is 40 characters maximum. If the number to be dialled back (along with the final colon) is omitted, a password check will be performed, but no call-back will occur. Up to 4 password/telephone number pairs may be entered.
AT *Pn: <password>:<number to be dialled back> n: 0 to 3.
Country Codes
AT +GCI Country of Installation. This extended syntax command selects and indicates the country of installation for the modem. This parameter selects the settings for any operational parameters that need to be adjusted for national regulations or telephone networks. Note: It is possible to change the factory set country codes in the modem manually or by means of the enclosed LASAT Data Fax Voice software. It is, however, important to notice that such a change may result in modem operational problems. Moreover, the new country code set-up in the modem may violate the national approval.
Country Code Country Code
Australia 09 Hungary 51
Austria 0A India 53
Belgium 0F Ireland 57
Bulgaria 1B Israel 58
Canada 20 Italy 59
China 26 Japan 0
Czech and Slovakia Federal Republic 2E Korea 61
Denmark 31 Luxembourg 69
Finland 3C Mexico 73
France 3D Netherlands 7B
Germany 42 New Zealand 7E
Greece 46 Norway 82
Hong Kong 50 Philippines 89
Poland 8A Portugal 8B
Russia B8 Singapore 9C
Spain A0 Sweden A5
Switzerland A6 Taiwan FE
United Kingdom B4 United States B5
AT -K MNP extended services. Enables or disables conversion of a V.42 LAPM connection to an MNP 10 connection. The parameter value, if valid, is written to S40 bit 0.
AT -K0 Disables V.42 LAPM to MNP 10 conversion (default).
AT - K1 Enables V.42 LAPM to MNP 10 conversion.
AT - K2 Enables V.42 LAPM to MNP 10 conversion; inhibits MNP Extended Services initiation during V.42 LAPM answer mode detection phase.
AT -Q0 Disables fallback to 2400bps (V.22bis) and 1200bps (V.22). Fallback is enabled only to 4800bps.
AT -Q1 Enables fallback to 2400bps (V.22bis) and 1200bps (V.22) (default). The parameter value, if valid, is written to S40 bit 1.
AT -SDR=n Distinctive Ringing.
n=0 Disable Distinctive Ring. Any valid ring detected is reported as RING (default).
n=1 Enables Distinctive Ring Type 1 (RING1).
n=2 Enables Distinctive Ring Type 2 (RING2).
n=3 Enables Distinctive Ring Type 1 and 2 (RING1, RING2).
n=4 Enables Distinctive Ring Type 3 (RING3).
n=5 Enables Distinctive Ring Type 1 and 3 (RING1, RING3).
n=6 Enables Distinctive Ring Type 2 and 3 (RING2, RING3).
n=7 Enables Distinctive Ring Type 1, 2, and 3 (RING1, RING2, RING3).
AT )M0 Disables power level adjustment during MNP 10 link negotiation (default).
AT )M1 Enables power level adjustment during MNP 10 link negotiation. For reliable links to accommodate the signalling requirements of cellular telephone equipment. The parameter value, if valid, is written to S40 bit 2.
AT @Mn initial cellular power level setting n= 0-31. Sets the initial transmit power level for upshift at connect until line conditions can be determined. @M0 corresponds to -26 dBm, @M1 corresponds to -30 dBm, @ M2 through @ M10 correspond to - 10 dBm, and @ M11 through @ M31 correspond to - 11 dBm to -31 dBm, respectively. The parameter value, if valid, is written to S201 bits 0-4.
AT :E0 Disables the equaliser
AT :E1 Enable compromise equaliser. The parameter value, if valid, is written to S201 bit 5. This command can be used when the modem is attached to either a flat line or a cellular connection.
+MS Modulation Selection This extended-format compound parameter controls the manner of operation of the modulation capabilities in the modem. It accepts six subparameters:
Syntax +MS=[<carrier>[,<automode>[,<min_tx_rate>[,<max_tx_rate>[,<min_rx_rate>[,<max_rx_rate>]]]]]]
Where: Possible <carrier>, <min_tx_rate>, <max_tx_rate>, <min_rx_rate>, and <max_rx_rate values are listed in are (see definitions below):
Defined Values: <carrier> A string which specifies the preferred modem carrier to use in originating or answering a connection. <carrier> values are strings of up to eight characters, consisting only of numeric digits and upper case letters. <carrier> values for ITU standard modulations take the form: <letter><1-4 digits><other letters as needed>. Defined values are listed in the table above. <automode> A numeric value which enables or disables automatic modulation negotiation (e.g., ITU-T V.32 bis Annex A or V.8).
0 = Automode disabled.
1 = Automode enabled. (Default.)
<min_rx_rate> and <max_rx_rate> Numeric values which specify the lowest (<min_rx_rate>) and highest (<max_rx_rate>) rate at which the modem may establish a receive connection. May be used to condition distinct limits for the receive direction as distinct from the transmit direction. Values for this subparameter are decimal encoded, in units of bit/s. The possible values for each modulation are listed in the table above. Actual values will be limited to possible values corresponding to the entered <carrier> and fall-back <carrier> as determined during operation. (Default = lowest (<min_rx_rate>) and highest (<max_rx_rate>) rate supported by the selected carrier.) <min_tx_rate> and <max_tx_rate> Numeric values which specify the lowest (<min_tx_rate>) and highest (<max_tx_rate>) rate at which the modem may establish a transmit connection. Non-zero values for this subparameter are decimal encoded, in units of bit/s. The possible values for each modulation are listed in the table above. Actual values will be limited to possible values corresponding to the entered <carrier> and fall-back <carrier> as determined during operation. (Default = lowest (<min_tx_rate>) and highest (<max_tx_rate>) rate supported by the selected carrier.)
+MS? Reporting Current or Selected Values Response: +MS: <carrier>,<automode>,<min_tx_rate>,<max_tx_rate>,<min_rx_rate>,<max_rx_rate> Note: The current active settings are reported under control of the +MR parameter. Example: +MS: K56, 1,300,33600,300,56000 For default values. This example allows maximum system flexibility to determine optimal receive and transmit rates during operation. Command: +MS=? Reporting Supported Range of Parameter Values Response: +MS: (< carrier> range),(<automode> range),(<min_tx_rate> range),(<max_tx_rate> range), (<min_rx_rate> range), (<max_rx_rate> range) Example: +MS: (B103,B212,V21,V22,V22B,V23C,V32,V32B,V34,K56,V90),(0,1),(300-33600),(300-33600), (300-56000),(300-56000)
AT+ES Error Control and Synchronous Mode Selection. This extended-format command specifies the initial requested mode of operation when the modem is operating as the originator, optionally specifies the acceptable fallback mode of operation when the modem is operating as the originator, and optionally specifies the acceptable fallback mode of operation when the modem is operating as the answerer.
AT+ES0 Initiate call with Direct Mode.
AT+ES1 Initiate call with Normal Mode (also referred to as Buffered Mode) only.
AT+ES2 Initiate V.42 without Detection Phase. If V.8 is in use, disable V.42 Detection Phase.
AT+ES3 Initiate V.42 with Detection Phase. (Default.)
AT+ES4 Initiate MNP.
AT+ES7 Initiate Frame Tunneling Mode when connection is complete, and Data Mode is entered.
AT+ESA Configure Synchronous Access Submode.
AT+IPR Fixed DTE Rate. This numeric extended-format parameter specifies the data rate at which the modem will accept commands during online operation. It may be used to select operation at rates at which the modem is not capable of automatically detecting the data rate being used by the DTE. Specifying a value of 0 disables the function and allows operation only at rates automatically detectable by the modem. The specified rate takes effect following the issuance of any result code(s) associated with the current command line.
The available rates are: 0, 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, or 115200. If unspecified or set to 0, automatic detection is selected and the character format is also forced to auto detect, +ICF=0. If the rate specified is not supported by the modem, an ERROR result code will be returned.
Fax Class I Commands
AT+FCLASS Select Service Class
AT+F<commands>? Report Active Configuration
AT+F<commands>=? Report Operating Capabilities
AT+FAE Data/Fax Auto Answer
AT+FTS Stop Transmission and Wait
AT+FRS Receive Silence
AT+FTM Transmit Data
#UD Last Call Status Report #UD is an action command requesting reporting of logged operation events. It does not take parameters and must be the last command in the command line. The modem logs aspects of their operation for each call, and saves these results until cleared by one of the following events:
1. Power off
2. Hard reset (e.g., negate DTR with &D3 set; reset button)
3. Soft reset = ATZ or AT&F
4. ATD command issued
5. ATA command issued
6. Automatic answer (e.g., set register S0>0 and ring detected)
These results are NOT cleared by changing DTR, V.24 circuit 108.2, if &D0, &D1 or &D2.
Voice / Audio Commands
+FCLASS Select data, fax or voice mode
+FCLASS=8 Select voice mode
+FCLASS=80 Select voice view mode
+VDR Distinctive ring. This command causes the modem to enable or disable reporting of the ring cadence information and to control the timing of the RING event code report if ring cadence reporting is enabled.
+VDR=0 (The defined value is <enable>).The modem will not report ring cadence information.
+VDR=1 (The defined value is <enable>).The modem will report ring cadence information as specified for the <report> subparameter.
+VDR=0 (The defined value is <report>) The modem will produce only DROF and DRON messages. The modem will not produce any RING event codes. The modem will report other call progress event codes as normal. Other. The modem will produce only DROF and DRON messages. The modem will produce a RING event code after <report>/10 seconds after the falling edge of the ring pulse (i.e., after the DRON report).
+VIP Voice Initialise All Parameters. This command causes the modem to initialise all voice parameters to their default values.
+VNH Automatic Hang-up Control. This command enables or disables automatic hangups.
+VNH=0 The modem enables automatic hang-ups as is normal in other modes.
+VNH=1 The modem disables automatic hang-ups usually found in the other non-Voice Modes.
+VNH=2 The modem disables automatic hang-ups in the other non-Voice Modes. The modem performs only a "logical" hang-up (returns to OK result code).
+VRX Start Modem Receive (Record). This command causes the modem to start the voice reception process.
+VTX Start Modem Transmit (Playback). This command causes the modem to start the voice transmission process.
+VGR=0 Voice Gain Receive (Record Gain). 0 is the only valid number. Selects automatic gain control.
+VGT Voice Gain Transmit (Playback Volume). This command causes the modem to set the volume level. Defined Values <level> Decimal number (120-135) corresponding to the volume level.
+VIT Voice Inactivity Timer (DTE/Modem). This command sets the modem’s initial value for the DTE/modem inactivity timer. Defined Values <timer> Decimal number(0 and 255) corresponding to the time in units of 1.0 second. A value of 0 disables the timer.
+VRA Ringback Goes Away Timer. This command sets the length of time the modem will wait between ringbacks during call origination before the modem can assume that the remote station has gone off hook. Defined Values <interval> Decimal number (0-255) specifying the silence interval time in units of 0.10 second between the end of one ring interval and the start of the next ring interval. A value of 0 forces the modem to report the OK result code immediately after the first Ringback. The range is 0.01 to 2.55 seconds for <interval> = 1 to 255.
+VRN Ringback Never Appeared Timer. This command sets the length of time the modem will wait between ringbacks during call origination before the modem can assume that the remote station has gone off hook. Defined Values <interval> Decimal number (0-60) specifying the time period, in units of 1.0 second, that the modem will wait for Ringback during call origination. A value of 0 forces the modem to report the OK result code immediately after dialing. The range is 1 to 60 seconds for <interval> = 1 to 60.
+VSD Silence Detection (Quiet and Silence). This command causes the modem to set the silence detection sensitivity and the required period of silence before the modem reports silence detected at the end of a voice receive either with the "Presumed End of Message" (QUIT) or "Presumed Hang-up (SILENCE) event reports. Defined Values: <sds> Decimal number corresponding to the selected parameter. 0 Use +VSM silence compression setting and algorithm for long-term silence detection (if +VSM is in use) or proprietary silence compression setting and algorithm for long-term silence detection (if +VSM is not in use). 127 Sets less aggressive long-term silence detection independent of presence or use of silence compression. 128 Sets nominal long-term silence detection independent of presence or use of silence compression. 129 Sets more aggressive long-term silence detection independent of presence or use of silence compression.
+VTD Beep Tone Duration Timer. This command causes the modem to set the default DTMF/tone generation duration. Defined Values <dur> Decimal number specifying the default DTMF/tone generation duration in units of 0.01 second. A value of 0 specifies the value entered by the S11 parameter (50-255 ms). The range is 0.01 to 2.55 seconds for <dur> = 1 to 255.
+VDT Control Tone Cadence Reporting. This command allows the modem to enable or disable reporting of the control tone cadence information in the frequency band used by the Ringback/Remote Ring, BUSY, and reorder/Fast Busy tones (usually in the 300to 600 Hz range).
Defined Values: <enable> Decimal number corresponding to the selected option. 0 The modem will not produce any control tone cadence report. 1 The modem will produce control tone cadence report as specified for the <report> subparameter. <report> Decimal number specifying the produced any control tone cadence report when enabled by the <enable> subparameter. 0 The modem will produce only CPOF and CPON messages. Other Reserved.
+VPR Select DTE/Modem Interface Rate (Turn Off Autobaud). This command selects the DTE/modem interface rate. Defined Values: <rate>> Decimal number corresponding to the DTE/modem interface rate where 0 = autobaud rate determined by processing the AT command, and 1,2,3,4,8,16,24,48,96 correspond to multipliers of 2400 bps to determine the actual rate:
0 = Autobaud
1 = 2400 bps
2 = 4800 bps
3 = 7200 bps
4 = 9600 bps
8 = 19200 bps
16 = 38400 bps
24 = 57600 bps
48 = 115200 bps
96 = 230400 bps
Speaker Phone Commands
+VSP Speakerphone ON/OFF. This command turns the speakerphone ON or OFF
+VSP=0 The speakerphone function is OFF. (Default.)
+VSP=1 The speakerphone function is ON.
+VDX Speakerphone Duplex Mode. This command selects speakerphone full duplex mode.
+VXD=1 The speakerphone mode is full duplex.
+VGM Microphone Gain. This command causes the modem to set the microphone gain of the speakerphone function. Defined Values: <gain> Decimal number between 0 and 255 corresponding to the gain.
+VGS Speaker Gain. This command causes the modem to set the speaker gain of the speakerphone function. Defined Values: <gain> Decimal number between 0 and 255 corresponding to the gain.