Chapter 2 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (S000273G) 7
Values: n = 0 or 1
Default: 0
Description: Q0 Enables result codes.
Q1 Disables result codes
Values: r is the S-Register number
Default: None
Description: Selects register Sr as the last register accessed; e.g., S0. The command AT? can then be
used to read the register, and the command AT=n can then be used to set the register to
value n.
Values: r is the S-Register number; n varies
Default: None
Description: Sets value of register Sr to n, where n is entered in decimal format; e.g., S0=1.
If the short form AT=n is used, the value is written to the last accessed S-Register.
Values: r is the S-Register number
Default: None
Description: Reads value of register Sr and displays it in 3-digit decimal format. S2? gives the
response 043. If the short form AT? is used, the last accessed S-Register is read.
Values: P,T
Default: T
Description: Forces DTMF (touch-tone) dialing until a P command or P dial modifier is received.
Values: n = 0 or 1
Default: 1
Description: V0 Displays result codes as digits (terse response).
V1 Displays result codes as words (verbose response)
Values: n = 0, 1, or2
Default: 0
Description: W0 The CONNECT result code reports the serial port speed only.
W1 The CONNECT result code reports the line speed, the error correction protocol,
and the serial port speed, respectively.
W2 The CONNECT result code reports the line speed only.
Note: See also the \V command
Values: n = 0–4
Default: Cou ntry Dependent
Description: Selects the result message subset that the modem will use to inform the computer of the
results of commands.
X0 Sends OK, CONNECT, RING, NO CARRIER, ERROR and NO ANSWER; does not
look for dial tone or busy signal.
X1 Sends X0 messages and connect speed; doesn’t look for dial tone or busy signal.
X2 Sends X1 messages with NO DIALTONE; does not look for busy signal.
X3 Sends X1 messages with BUSY; does not look for dial tone.
X4 Sends all messages, including NO DIALTONE and BUSY.
Note: In fax mode, the only message sent to indicate a connection is CONNECT without
a speed indication. See also the \V command.