Comandos Hayes

Command Guidelines

Each AT command has a list of possible parameters with its default value. The default value (in bold type) is loaded at initialization, i.e. power turn on or ATZ command. If a command requires a parameter but no parameter is entered, the modem assumes the parameter is zero. Invalid commands or parameters return the ERROR message.

The command line may contain a single command or a series of commands. The commands may be separated by a space for readability. The command line can be up to 40 characters in length. The command line is executed after a terminating character is entered. The default terminating character is a carriage return (ASCII 013), but this may be changed by writing a different value to reg. S3.

The command line may be edited using the backspace character (ASCII 008). This value may be programmed using the S5 register. However, the backspace will not work for values of 0 and greater than 127, or for the current value of the terminating character. All command lines must begin with AT entered in capital or lower case letters. A command line can be terminated at any time by issuing CTRL-X (ASCII 018) after entering AT attention code. The command line will be ignored and an OK result message will be issued. The A/ command may be used to repeat the last command line. The A/ does not require a terminating character or the AT attention code.

The escape code sequence returns the modem to the command mode from the data mode. A time delay must occur between the last character transmitted and the first character of the escape code. The guard time delay can be changed by writing a value to register S12; (default 1 second). The escape code character must occur three times in succession for an escape.

Parameters that are entered for the AT and AT& commands are limited in value to 0-255, where the parameter is "MOD"ed with 256. The result must be within the specified range; if it is not, the ERROR message is issued.

Parameters entered for an S register are also "MOD"ed with 256 and the result is stored in the S register. Parameters that are out of range are stored in the S register, however, no ERROR message is reported. Functionally, however, the lower or higher limit is observed. Parameters entered for the AT\ and AT% commands follow the same method, except that if the parameter is out of range, the upper limit is stored and no ERROR message is reported.

Table AT Command Definitions

Command Function

A/ Re-execute Command.

ATA Answer Command.

ATBn Set CCITT or Bell Mode.

Command options :

ATB0 = Selects CCITT V.22 bis, V.22, and V.21 standards for communication at 2400, 1200, and 300 bps.

ATB1 = Selects Bell 212A and 103 standards for communication at 1200 and 300 bps.

ATB15=*Select V.21 connection at 300 bps.

ATB16=*Select Bell 103 connection at 300 bps.

ATCn Carrier Control.

Command options :

ATC0 =** Not permitted ; returns ERROR result code.

ATC1 = Normal transmit carrier switching (preset).

ATDn Dial.

The ATD parameters are :

L Dials the last dial string that was dialed.

P Use Pulse Dialing. Placed at the end of the command string and before the dial string. Causes the modem to pulse dial the numbers.

T Use DTMF Dialing. Placed at the end of the command string and before the dial string. Causes the modem to use DTMF tones to dial.

R Reverse Mode. Allows the modem to call an originate only modem by forcing the call into "answer mode". Must be entered as the last character of the command string (just before the <CR>).

! Hookflash. Causes the modem to go on-hook for 700 milliseconds and then off-hook.

@ Causes the modem to listen for 5 seconds of silence. If a 5 second silence has not been detected within the period specified in S7 (default = 30 seconds),

the modem disconnects and returns the "NO ANSWER" result code. If it detects a busy signal, it returns a "BUSY" result code. If the 5 seconds of silence is detected,then the modem continues dialing the string.

W Wait For Dial Tone Before Dialing. Causes the modem to wait for a dial tone up to the period of time specified in register 7 (default = 30 seconds) before dialing the numbers that follow. If the modem detects a dial tone before the given time delay, it continues to dial. Otherwise, it goes on-hook.

, Pause During Dial. Inserted between digits in a dial string. Causes the modem to pause for the value given by register S8 (default = 2 seconds), before dialing the next digit. This delay can be used in place of the "Wait For Dial Tone Before Dialing".

; Return To Command Mode After Dialing. Added to the end of the dial string. Causes the modem to remain in the command mode after it dials the digits preceding the command.This allows the user to issue additional dial commands or dial strings without overflowing the command buffer. The modem looks for the carrier after the final dial command is issued."ATHn" aborts this command.

^ Turn On Calling Tone. Turns on the periodic 1300 Hz calling tone if originating the call. Calling tone is enabled only on a call-by-call basis.

S=n Dial Stored Number. Follows the dial command string. Causes the modem to dial a telephone number previously stored in directory location n using AT&Zn command. If "ATD" is entered without parameters, the modem goes off-hook and waits for carrier; if the handshake is not completed within the period of time specified by register S7(default = 30 seconds), the modem goes on on- hook. The ATD command will be aborted in progress upon receipt of any character from the DTE before completion of the handshake.

ATE Command Echo.

Command options :

ATE0 = Inhibits the echoing of commands.

ATE1 = Enables the echoing of commands.

ATFn On-Line State Character Echo.

Command options :

ATF0 = Error.

ATF1 = Disables on-line echo.

ATF2 = Reserved

ATF3 = Select V.23 line modeulation

ATF4 = Select V.22 or Bell 212A 1200 bps line speed

ATF5 = Select V.22 bis line modulation

ATF6 = Select V.32 bis or V.32 4800 line modulation

ATF7 = Select V.32 bis 7200 line modulation

ATF8 = Select V.32 bis or V.32 9600 line modulation

ATF9 = Select V.32 bis 12000 line modulation

ATf10= Select V.32 bis 14400 line modulation

ATHn Switch-Hook Control.

Command options :

ATH0 = Causes the modem to go on-hook (hang up).

ATH1 = If modem is on-hook, modem goes off-hook, returns an OK response, and awaits further commands.

ATIn Identification.

Command options :

ATI0 = Reports the product code.

ATI1 = Reports the checksum computed on the firmware ROM.

ATI2 = Performs a checksum on the firmware ROM and indicates OK or ERROR.

ATI3 = Reports firmware revision level.

ATI4 = Reports product capabilities.

ATI5 = Report the country code number

ATLn Speaker Volume.

Command options :

ATL0 = Selects low speaker volume.

ATL1 = Selects low speaker volume.

ATL2 = Selects medium speaker volume.

ATL3 = Selects high speaker volume.

ATMn Speaker Control.

Command options :

ATM0 = Speaker is always off.

ATM1 = Speaker goes off while the modem is receiving a carrier signal from a remote modem.

ATM2 = Speaker is always on.

ATM3 = Speaker goes off while the modem is receiving a carrier signal from a remote modem and while the modem is dialing.

ATNn Modulation Handshake.

Command options :

ATN0 = Requires that the speed of the connection be that specified by the value held in S37; if S37=0, the speed of the connection must match that at which the last AT command was issued. If the selected speed can be achieved using more than one comunication standard (e.g. Bell 212A or CCITT V.22 at 1200 bps), the modem also references the selection made with the ATB command.

ATN1 = Permits handshaking t occur at any speed supported by both modems. Enables automode detection. The ATB command is ignored in this mode and the modem attempts only CCITT mode connections.

ATN2 = Originate: Handshake per S37 and Bn; fallback Answer: Negotiabte per V.22 bis, V.22, and V.21

ATN3 = Originate: Handshake only per S37 and BnAnswer:Negotiate per V.22bis, V.22, V.23, and V.21

ATN4 = Originate: Handshake only per S37 and Bn Answer:Negotiate per V.22bis, V.22, V.23, and V.21

ATN5 = Originate: Handshake per S37 and Bn; fallback Answer: Handshake only per S37 and Bn

ATOn Return to the On-Line State.

Command options :

ATO0 = Causes the modem to return to the data mode.

ATO1 = Causes the modem to return to the data mode and to initiate a retrain when operating at any speed.

ATP Set Pulse Dial as Default.

ATQn Result Code Display.

Command options :

ATQ0 = Allows the modem to send result codes to the DTE.

ATQ1 = Prohibits the modem from sending result codes to the DTE. ATQ2 = Modem returns result codes to the DTE when originating a call; does not return result codes when answering a call.

ATSn? Reading S Registers.

ATSn=x Writing to S Registers.

ATT Set Tone Dial as Default.

ATVn Result Code Form (Message Control).

Command options :

ATV0 = Allows short-form (numeric) result codes to be sent.

ATV1 = Allows long-form (verbose) result codes to be sent.

ATWn Negotiation Progress Reporting.

Command options :

ATW0 = Error-correction call progress not reported.

ATW1 = Error-correction call progress reported.

ATW2 = Error-correction call progress not reported.CONNECT XXXX message reports DCE speed.

ATXn Extended Result Codes.

Command options :

ATX0 = Modem ignores dial tone and busy signal. Sends CONNECT message when a connection is established by blind dialing. ATX1 = Modem ignores dial tone and busy signal. Sends CONNECT XXXX message reflecting bit rate when a connection is established by blind dialing.

ATX2 = Modem ignores busy signal but waits for dial tone before dialing. If dial tone is not detected within 5 seconds, the NO DIALTONE message is sent. Sends CONNECT XXXX message reflecting bit rate when a connection is established.

ATX3 = Modem ignores dial tone. Sends BUSY message if a busy signal is detected. Sends CONNECT XXXX message reflecting bit rate when a connection is established by blind dialing.

ATX4 = If dial tone is not detected within 5 seconds, sends NO DIAL TONE message. If busy signal is detected, sends BUSY message. Sends CONNECT XXXX message reflecting bit rate when aconnection is established.

ATYn Control Long Space Disconnect.

Command options :

ATY0 = Disable long space disconnect.

ATY1 = Enable long space disconnect.

ATZn Reset. Causes the modem to disconnect and performs a warm start.

AT&Cn Data Carrier Detect (DCD) Option.

Command options :

AT&C0 =RLSD is ON regardless of the state of the data carrier from the remote modem.

AT&C1 =RLSD follows the state of the data carrier from the remote modem.

AT&Dn Data Terminal Ready (DTR) Option.

The action for the event that follows DTR loss is indicated in the following table :

&D0 &D1 &D2 &D3

&Q0 NONE 2 3 4

&Q1 1 2 3 4

&Q2 3 3 3 3

&Q3 3 3 3 3

&Q4 1 2 3 4

The DTR-going-off events corresponding to the action numbers in the above table are :

1. Modem disconnects and sends OK result code.

2. Modem goes into command mode if in data mode and sends the OK result code.

3. Modem disconnects, sends the OK result code, and disables auto answer while DTR is OFF.

4. Modem performs a warm start (i.e. same as ATZ command). This is the DTE/AT&D3 abort.

AT&F0 = Restore factory profile 0

AT&F1 = Restore factory profile 1

AT&Gn Set Guard Tone.

Command options :

AT&G0 = Disable guard tone generation.

AT&G1 = Disable guard tone generation.

AT&G2 = Enable 1800 Hz guard tone generation.

AT&Jn Telephone Jack Selection.

Command options :

AT&J0 =Suitable for RJ-11, RJ-41S, or RJ-45S type phone jack. The auxiliary relay is never operated.

AT&J1 =Suitable for RJ-12 or RJ-13 type phone jack. The A lead is connected to A1 lead while modem is off-hook. If AT&J0 is selected, the auxiliary telco relay is opened. If AT&J1 is selected and the modem is off-hook, the auxiliary telco relay (A/A1) is closed (shorting A to A1).

AT&Kn DTE/Modem Flow Control.

Command options :

AT&K0 = Disables flow control.

AT&K3 = Enables RTS/CTS flow control.

AT&K4 = Enables XON/XOFF flow control.

AT&K5 = Enables transparent XON/XOFF flow control.

AT&K6 = Enable RTS/CTS and XON/XOFF DTE/DCE flow control

AT&Ln Line Type.

Command options :

AT&L0 = Dial-up line.

AT&L1 = Leased line.

AT&Mn Asynchronous Communication Mode.

AT&Pn Dial Pulse Ratio.

Command options :

AT&P0 = 39% / 61% make/break ratio @ 10 pps.

AT&P1 = 33% / 67% make/break ratio @ 10 pps.

AT&P2 = 33% / 67% make/break ratio @ 20 pps.

AT&P3 =* 33% / 67% make/break ratio @ 20 pps.

AT&Qn Communication Mode.

Command options :

AT&Q0 =Selects asynchronous operation in the Direct mode. In this mode, the DTE speed must match the telco line speed.

AT&Q1 = Selects synchronous mode 1 operation. Supports terminals that are able to communicate in both asynchronous and synchronous protocols. Uses the dial command to place a call in asynchronous mode then switches to synchronous mode once the connection is made. The modem goes on-hook and switches back to the asynchronous mode when it detects an ON-to-OFF transition on DTR or a loss of carrier from the remote modem exceeding the time interval given by register S10 (default = 1.4 seconds).

AT&Q2 = Selects synchronous mode 2 operation. Supports synchronous terminals with stored number dialing. The modem automatically dials a stored number when it detects an OFF-to-ON transition on DTR. An asynchronous terminal is still needed to save or change the phone number stored in the NVRAM; the number is saved using the "AT&Z0=x" command. The modem dials the number stored in the first entry. The modem goes on-hook and switches back to the asynchronous mode when an ON-to-OFF transition on DTR is detected or a loss of carrier occurs from the remote modem exceeding the time interval given by register S10 (default = 1.4 seconds).

AT&Q3 = Selects synchronous mode 3 operation. This mode allows DTR to act as a Talk/Data switch. The operator manually initiates a call with DTR OFF, implying the modem is in Talk mode. To complete the call, the operator switches the modem to Data mode by turning DTR ON after the last number is dialed. The modem goes on-hook and switches to the asynchronous mode when an ON-to-OFF transition on DTR is detected or a loss of carrier occurs from the remote modem exceeding the time interval given by register S10 (default = 1.4 seconds).

AT&Q4 =This command causes the modem to issue OK result code but has no effect on operation.

AT&Q5 =Selects error correction mode. Modem negotiates an error-correction link. The modem can be configured to either disconnect or fallback to a normal asynchronous connection if the link cannot be negotiated (refer to register S36).

AT&Q5 and S36=0 : same as AT\N2 (no fallback).

AT&Q5 and S36=1 : same as AT\N3 (fallback) (see AT\N command).

AT&Q6 =Selects asynchronous operation in Normal mode (Speed Buffering). In this mode, the DTE speed can differ from the telco line speed.

AT&Rn RTS/CTS Option.

Command options:

AT&R0 =CTS tracks RTS. CTS is turned ON in response to an OFF-to-ON transition of RTS from the local DTE after a delay period specified by register S26 in increments of 10 milliseconds (default = 0).

AT&R1 =The modem ignores RTS; CTS is held ON.

AT&Sn Data Set Ready (DSR) Option.

Command options :

AT&S0 =DSR is always on.

AT&S1 =DSR is turned ON at start of handshaking and OFF when in a test mode or idle state. DSR is turned OFF when carrier is lost.

AT&Tn Test and Diagnostic.

Command options :

AT&T0 =End test in progress. The escape sequence must be issued to return the modem to the command mode prior to sending this command. Subsequent issuing of the ATO command while in the command mode will cause the local and remote modems to return to normal data mode operation if the interrupted test was digital loopback.

AT&T1 =Initiates local analog loopback. This test verifies the working condition of the path between the local DTE and the local modem. The characters received from the DTE are looped back to the DTE by the modem.

AT&T3 =Initiates remote digital loopback locally. The characters received from the remote modem are looped back to the remote modem by the local modem. This test verifies the working condition of the path from a remote modem, through a local modem, and back to the remote modem.

AT&T4 =Allows the modem to respond to a request from a remote modem for a remote digital loopback test.

AT&T5 =Prohibits the modem from granting a request from a remote modem for a remote digital loopback test.

AT&T6 =Initiates remote digital loopback. The characters received from the local DTE are transmitted to the remote modem and looped back from the remote modem to the local modem and DTE. This test verifies the working condition of the path between the local DTE and the remote modem.

AT&T7 =Initiates remote digital loopback with self test. This test works similarly to AT&T6 except that the modem sends an alternating zeros and ones (0101) test pattern to the remote modem and continuously examines the validity of the returned data. The modem increments an internal error counter each time an error is detected. At the end of the test, the modem returns a 3-digit error count to the DTE.

AT&T8 =Initiates local analog loopback with self test. This test works similarly to AT&T7 except that the test pattern is checked in the local analog loopback mode (as in AT&T1). This allows a thorough testing of the local modem transmit and receive functions without an actual telco line connection.

AT&V View Current Configuration and User Profiles. Displays the active configuration and user profiles.

AT&Wn Store User Profile.

Command options :

AT&W0 = Save as user profile 0.

AT&W1 = Save as user profile 1.

AT&Xn Clock Source Selection.

Command options :

AT&X0 = Internal timing. The modem generates the transmit clock signal and applies it to the EIATXCLK output at the serial interface.

AT&X1 = External timing. The local DTE sources the transmit clock signal on the SPXEXTCLK input of the serial interface. The modem applies this clock to the EIATXCLK output at the serial interface.

AT&X2 =Slave receive timing. The modem derives the transmit clock signal from the incoming carrier and applies it to the EIATXCLK output at the serial interface.

AT&Yn Designate Default User Profile.

Command options :

AT&Y0 =Selects user profile 0.

AT&Y1 =Selects user profile 1.

AT&Zn=x Store Phone Number. Stores a 36-digit dial string(x) in the specified entry(n) or later dialing. (See ATDS=n command.)

AT\An Maximum MNP Block Size.

Command options :

AT\A0 =Sets maximum block size to 64 characters.

AT\A1 =Sets maximum block size to 128 characters.

AT\A2 =Sets maximum block size to 192 characters.

AT\A3 =Sets maximum block size to 256 characters.

AT\Bn Transmit Break.

AT\Gn Modem to Modem Flow Control.

Command options :

AT\G0 =Disables flow control (XON/XOFF).

AT\G1 =Enables flow control (XON/XOFF).

AT\Kn Break Control.

Command options :

When a BREAK is received from the DTE during Normal or MNP mode, the modem takes the following action: AT\K0,2,4 = Modem enters the command mode (waiting for AT) without sending a BREAK to the remote modem.

AT\K1 =Modem clears the terminal and modem buffers and sends a BREAK to the remote modem.

AT\K3 =Modem does not clear the buffers but sends a BREAK to the remote modem.

AT\K5 =Modem sends a BREAK to the remote modem in sequence with any transmitted data. When a BREAK is received from the remote modem during Normal mode, the modem takes the following action :

AT\K0,1 = Modem clears the terminal and modem buffers and sends a BREAK to the local DTE.

AT\K2,3 = Modem does not clear buffers but sends a BREAK to the local DTE.

AT\K4,5 = Modem sends a BREAK in sequence with any data being buffered. When a BREAK is received from the DTE during Direct mode, the modem takes the followig action :

AT\K0,2,4 = Modem sends a BREAK to remote modem and enters command mode (waiting for AT).

AT\K1,3,5 = Modem sends a BREAK to remote modem.

AT\Kn Note: In LAPM, breaks are "timed", meaning the modem attempts to preserve the duration of the break when transmitting it to the remote mo dem. IN MNP4, breaks are not "timed", as MNP4 has no facility for maintaining the duration of the signal; a long break is the same as a short break.

AT\Ln MNP Block Transfer Control.

Command options:

AT\L0 =Uses Stream mode for MNP link connections.

AT\L1 =Uses Block mode for MNP link connections.

AT\Nn Operation Mode Control.

Command options :

AT\N0 =Selects Normal (speed buffering) mode.This option takes effect at physical connection time.

AT\N1 =Selects Direct (pass through) mode.This option takes effect at physical connection time. If the parallel interface is selected (SEREN = low), the AT\N1 is interpreted as AT\N0 since Direct mode is not available with the parallel interface.

AT\N2 =Selects reliable link mode. This defines the modem-to-modem connection to require error correction. If an attempt to establish the reliable link fails, the modem disconnects. This command takes effect at physical connection time only. To establish MNP after a physical connection, use the AT\O, AT\U, or AT\Y command. AT\N3 =Selects auto-reliable link mode. The modem will attempt an error-correction connection but will fallback to normal mode if unable to establish an MNP link. This command takes effect at physical connection time only. To establish MNP after a physical connection, use the AT\O, AT\U, or AT\Y command.

AT\N4 =Force LAPM mode

AT\N5 =Force MNP mode

AT%Cn Compression Control.

Command options :

AT%C0 = Disables data compression.

AT%C1 = Enables data compression.

AT%C2 = Enable V.42 bis data compression

AT%C3 = Enable both V.42 bis and MNP 5 compression

AT%En Enable/Disable Auto-Retrain.

Command options :

AT%E0 = Disables auto-retrain.

AT%E1 = Enables auto-retrain.

AT%L Report Received Signal Level.

AT%Q Report Line Signal Quality. Returns the high-order byte of the calculated Eye Quality Monitor (EQM) value. The high-order byte can range from 0 to 255. However, when the value is 8 or greater, the modem will automatically retrain if enabled by the AT%E1 command. The value for a normal connection ranges from about 0 to 2 and approaches 8 for a progressively poorer connection.

Parameters : None.

Default : None.

Result codes : OK

AT%TT PTT certification test signal

S REGISTERS

The S registers affect various operating characteristics, they let you obtain information about your modem, and let you test your modem. Each register has a default value, which you can read or change to fit your particular requirements.

Table 3-1 shows the registers, their functions, and their default values. Some registers can have their values changed by commands.

All of the factory default values may be loaded at any time by entering the AT&F command.

Table 3-1. S Register Definitions Register Function

S0 Number of Rings till Auto-Answer. Establishes the number of the rings required before the modem answers the incoming calls. Setting this register to zero disables auto-answer mode.

Range : 0-255 rings.

Default : 0.

S1 Ring Counter. Number of the rings which the modem detects before it answers a call. If no rings occur over an eight-second interval, this register is cleared.

Range : 0-255 rings.

Default : 0.

S2 Escape Character. S2 holds the decimal value of the ASCII character used for the escape character. The default value corresponds to an ASCII'+'. A value over 127 disables the escape process, i.e. no escape character will be recognized.

Range : 0-255, ASCII decimal.

Default : 43.

S3 Carriage Return Character. Sets the command line and result code terminator character. Pertains to asynchronous operation only.

Range : 0-127, ASCII decimal.

Default : 13 (Carriage Return).

S4 Line Feed Character. Sets the character recognized as a line feed. Pertains to asynchronous operation only. The Line Feed control character is output after the Carriage Return control character if verbose result codes are used.

Range : 0-127, ASCII decimal.

Default : 10 (Line Feed).

S5 Backspace Character. Sets the character recognized as a backspace. Pertains to asynchronous operation only. The modem will not recognize the Backspace character if it is set to a value that is greater than 32 ASCII. This character can be used to edit a command line. When the echo command is enabled, the modem echoes back to the local DTE the Backspace character, an ASCII space character and a second Backspace character; this means a total of three characters are transmitted each time the modem processes the Backspace character.

Range : 0-32, ASCII decimal.

Default : 8 (Backspace).

S6 Wait Time for Blind Dialing. Sets the length of time to pause after the modem goes off-hook and before the modem dials the first digit of the telephone number. The modem always pauses for a minimum of 2 seconds even if the S6 register is set to a value less than 2 seconds. The "Wait For Dial Tone" call progress feature (W in the dial string) will override the value in register S6. If option ATX2 or ATX4 is in effect, this register is ignored.

Range : 2-255 seconds.

Default : 2.

S7 Wait for Carrier after Dial.

Defines two delay times :

1. During call establishment, this register establishes the time that the local modem waits for carrier from the remote modem before hanging up.

2. Sets the length of time that the modem waits when the "Wait For Dial Tone" call progress feature (W in the dial string) is in effect.

Range : 1-255 seconds.

Default : 50.