ETSI AT command set

Following a list of the ETSI command set which are the basic AT commands supported on all ETSI compliant devices. Click on the single command to read more information.

Feature Designator
Technical enhancement and improvement: New AT-commands $(AT R97)$
Technical enhancement and improvement: New AT-commands $(AT R98)$
Support of Multiplexer according to GSM 07.10 $(MUX MS-TE)$
Command Description
AT&A0 Originate/Answer Mode Selection: Enables answer mode
AT&A1 Originate/Answer Mode Selection: Disables answer mode
AT&B0 Auto-Retrain Detection: Disable auto-retrain (modem hangs up)
AT&B1 Auto-Retrain Detection: Enable auto-retrain
AT&B2 Auto-Retrain Detection: Enable auto-retrain
AT&C0 DCD Option: DCD always enabled
AT&C1 DCD Option: DCD enabled after a carrier signal is detected
AT&D0 Modem Response to DTR Option: DTR is assumed to be on
AT&D1 Modem Response to DTR Option: DTR drop causes the modem back to command mode, but does not drop
AT&D2 Modem Response to DTR Option: DTR drop causes modem to hang up
AT&D3 Modem Response to DTR Option: DTR drop causes the modem to be reinitialized
AT&F0 Active Profile/Factory Defaults: Default profile #1 (Works with many modems)
AT&F1 Active Profile/Factory Defaults: Default profile #2 (Works with many modems)
AT&F2 Active Profile/Factory Defaults: Default profile #3 (Works with many modems)
AT&F3 Active Profile/Factory Defaults: Default profile #4 (Works with many modems)
AT&G0 Guard Tone Option: Guard tone is disabled
AT&G1 Guard Tone Option: A 550 Hz guard tone is enabled
AT&G2 Guard Tone Option: A 1800 Hz guard tone is enabled
AT&J0 Jack Type Selection: Selects RJ-11, RJ-41s, or RJ45s
AT&J1 Jack Type Selection: Selects RJ-12 or RJ-13
AT&K0 Flow Control Selection: Flow control disabled
AT&K1 Flow Control Selection: Normally unused (deals with RTS/CTS)
AT&K2 Flow Control Selection: Normally unused (deals with XON/XOFF)
AT&K3 Flow Control Selection: Enable RTS/CTS flow control
AT&K4 Flow Control Selection: Enable XON/XOFF flow control
AT&K5 Flow Control Selection: Enable transparent XON/XOFF flow control
AT&K6 Flow Control Selection: Enable unidirectional XON/XOFF flow control
AT&L0 Line Type Selection: Selects public switched telephone network (normal dialup)
AT&L1 Line Type Selection: Selects leased line
AT&M0 Communication Mode Selection: Asynchronous
AT&M1 Communication Mode Selection: Synchronous connect mode, asynchronous offline command mode
AT&M2 Communication Mode Selection: Synchronous connect mode, asynchronous offline command mode (DTR set to high)
AT&M3 Communication Mode Selection: Synchronous connect mode
AT&P0 Make/Break Ratio for Pulse Dialing: North America: Selects 39%-61% make/break ratio at 10 pulses per second
AT&P1 Make/Break Ratio for Pulse Dialing: Europe: Selects 33%-67% make/break ratio at 10 pulses per second
AT&P2 Make/Break Ratio for Pulse Dialing: Selects 39%-61% make/break ratio at 20 pulses per second
AT&P3 Make/Break Ratio for Pulse Dialing: Selects 33%-67% make/break ratio at 20 pulses per second
AT&Q0 Communications Mode Option Selection: Asynchronous mode, the serial port speed will follow the connection speed
AT&Q1 Communications Mode Option Selection: Asynchronous off-line command mode, synchronous connect mode
AT&Q2 Communications Mode Option Selection: Asynchronous off-line command mode, synchronous connect mode (this option will also have the modem the first number in its directory)
AT&Q3 Communications Mode Option Selection: Asynchronous off-line command mode (low DTR), synchronous connect mode (high DTR)
AT&Q4 Communications Mode Option Selection: Auto-synchronous mode
AT&Q5 Communications Mode Option Selection: Error correction mode
AT&Q6 Communications Mode Option Selection: Buffered asynchronous mode
AT&Q8 Communications Mode Option Selection: Enables Microcom Networking Protocol (MNP) error control mode.
AT&Q9 Communications Mode Option Selection: V.42 or MNP error control mode.
AT&R0 RTS/CTS Option Selection:
AT&R1 RTS/CTS Option Selection:
AT&S0 DSR Option Selection: Force DSR high
AT&S1 DSR Option Selection: Force DSR high during handshake and connection
AT&S2 DSR Option Selection: Force DSR high will connected
AT&T0 Test Option Selection: End test
AT&T1 Test Option Selection: Begin a local analog loopback test
AT&T3 Test Option Selection: Begin a local digital loopback test
AT&T4 Test Option Selection: Allow a remote digital loopback test
AT&T5 Test Option Selection: Disallow a remote digital loopback test
AT&T6 Test Option Selection: Request a remote digital loopback test
AT&T7 Test Option Selection: Request a remote digital loopback test and a self test
AT&T8 Test Option Selection: Start a local analog loopback and self test
AT&U0 Trellis code modulation
AT&U1 Trellis code modulation
AT&V0 Display Current configuration and profile
AT&V1 S Registers Display
AT&W0 Active Profile Write: Write active profile into stored profile 0
AT&W1 Active Profile Write: Write active profile into stored profile 1
AT&X0 DTE Transmit Clock Source: Modem
AT&X1 DTE Transmit Clock Source: DTE
AT&X2 DTE Transmit Clock Source: Modem generates the clock with regards to the receiving carrier signal
AT&Y0 Active Profile Read: Restore from stored profile 0
AT&Y1 Active Profile Read: Restore from stored profile 1
AT&Zn=x Telephone Number Write