Modem Emulation AT Command Set

The following commands can be issued to perform actions in a modem-emulation configuration scenario.

AT
Command

Function

Result

Code

n+++n

When in data mode, this command causes the modem to switch to command mode. The value of n corresponds to the required delay before and after the escape sequence is entered. The delay can be changed by modifying S-register 12. The escape character can be changed by modifying S-register 2.

 

A/

Repeats the last command string.

 

AT?

Prints the value of the last-accessed S-register.

 

ATA

Answer command: Answers an incoming TCP connection and switches to data mode.

 

ATD (ipaddress): (ipport)

Used to connect to a remote network device. This command directs the Digi device to go on-line, dial according to the IP address entered as follows, and attempt to establish a TCP connection.

Dial Modifiers. The valid dial string parameters are described below. Punctuation characters may be used for clarity with parentheses, hyphen, and spaces being ignored.

  • 0-9: DTMF digits 0 through 9.
  • . (period): Dot notation used for IP addresses. IP addresses are written as four numbers separated by periods, where the first number is between 1 and 255, and the other three numbers are between 0 and 255. Enter the IP address in the format xxx.xxx.xxx.xxx
  • : (colon): Colon notation used for the TCP port.
  • L: Redial the last number. The modem will reconnect to the last IP address accessed. The L must immediately follow the D, and any following characters are ignored.
  • P: This command is accepted but not acted on.
  • T: This command is accepted but not acted on.
  • R: This command is accepted but not acted on.
  • , (comma): This command is accepted but not acted on.

 

ATEn

Command echo. The Digi device enables or disables the echo of characters to the DTE according to the parameter supplied. The parameter value, if valid, is written to S14 bit 1.

  • E0: Disables command echo.
  • E1: Enables command echo.

OK n=0 or 1

ERROR
Otherwise

ATH

Disconnect (Hang up) command.

H0, H1: Hangs up the TCP connection if a connection is active.

OK n=0 or 1

ERROR
Otherwise

ATIn

Identification command.

  • I0, I1: Reports product name.
  • I3: Reports product name, firmware revision.
  • I4: Reports product configuration.
  • I6: Reports network connection information.

OK n=0 or 9

ERROR
Otherwise

ATO

Return to on-line data mode. If the modem is in the on-line command mode, the modem enters the on-line data mode. If the modem is in the off-line command mode (no connection), ERROR is reported.

  • O0, O1: If there is an active connection, switches the modem to data mode.

OK n = 0 or 1 and a connection exists.

ERROR
Otherwise or if not connected.

ATQn

Quiet results codes control command. The command enables or disables the sending of the result codes to the DTE according to the parameter supplied. The parameter value, if valid, is written to S14 bit 2.

Q0: Enables result code to the DTE (Default).

Q1: Disables result code to the DTE.

Q2: Disables CONNECT result codes.

Q3: Disables CONNECT result codes on incoming connections.

OK n=0 or 1

ERROR
Otherwise

ATSn

Read/Write to the specified S-Register.

  • n Establishes S-register n as the last register accessed.
  • n=v Sets S-Register n to the
    value v.
  • n? Reports the value of S-Register n.

See S-Register Definitions for definitions of S-Registers.

OK n=0 or 1

ERROR
Otherwise

ATVn

The verbose setting for result codes. This command selects the sending of short-form or long-form codes to the DTE. The parameter, if valid, is written to S14 bit 3.

  • V0: Result codes are issued in numeric or short form. Line feeds are not issued before a short-form result.
  • V1: Result codes are issued in text or long form. This is the default.

OK n=0 or 1

ERROR
Otherwise

ATZ

Load configuration. Reloads the S-register configuration from flash memory. See S-Register Definitions for definitions of S-Registers.

OK n=0 or 1

ERROR
Otherwise

AT&Cn

DCD option. The Digi device controls the DCD output in accordance with the parameter supplied. The parameter value, if vali,d is written to S21 bit 5.

  • &C0: DCD remains ON at all times.
  • &C1: DCD follows the state of the connection.

OK n=0 or 1

ERROR
Otherwise

AT&Dn

DTR option. This command interprets the ON to OFF transition of the DTR signal from the DTE in accordance with the parameter supplied. The parameter value, if valid, is written to S21 bits 3 and 4. Also see S25.

  • &D0: DTR drop is ignored (assumed ON).
  • &D1: DTR drop is interpreted by the modem as if the asynchronous escape sequence had been entered. The modem returns to command mode without disconnecting.
  • &D2: DTR drop causes the modem to hang up. (Default.)
  • &D3: DTR drop causes the modem to do a soft reset, as if the ATZ command was executed.

OK n=0 to 3

ERROR
Otherwise

AT&F

Restore factory configuration. The device reloads the factory default S-register configuration from flash memory. The factory defaults are identified for each command and in the S-Register descriptions. A configuration consists of a subset of S-Registers.

OK n=0 or 1

ERROR
Otherwise

AT&V

Displays current values and settings.

  • AT&V0- AT&V5: Displays S-Register/command values for the current and stored configuration.
  • AT&V6: Displays current network settings.

OK n=0 to 5

ERROR
Otherwise

AT&Wn

Store configuration. Stores the specified S-registers in flash memory.

OK n=0 or 1

ERROR
Otherwise