Appendix E: AT Commands
47
Command
Function
S
n
Establishes S-register
n as the default register
S
n=v
Sets register
n to value v
S
n?
Returns the value of register
n
T
Tone dialing until P command
V0
Send numeric (terse) responses
V1
Send word (verbose) responses
W0
Reports DTE (computer-to-modem) speed only
W1
Reports DCE (modem-to-modem) speed, error correction
protocol, and DTE speed
W2
Reports DCE (modem-to-modem) speed only
X0
Sends OK, CONNECT, RING, NO CARRIER, ERROR and
NO ANSWER.
X1
Sends X0 messages and CONNECT speed
X2
Sends X1 messages and NO DIALTONE.
X3
Sends X1 messages and BUSY
X4
Sends all responses
Y0
Disables long space disconnect
Y1
Enables long space disconnect; with error correction, hangs
up after 1.6 second signal break; without error correction,
sends 4 second space before hanging up
Z0
Resets modem to profile 0. (See &W0.)
Z1
Resets modem to profile 1. (See &W1.)
&C0
Forces RLSD (DCD) on
&C1
RLSD (DCD) follows remote carrier
&D0
DTR is assumed on. Allows operation with DTEs that do not
provide DTR signal.
&D1
Modem interprets DTR drop as if it received the escape
sequence. Returns to command mode without disconnecting.
&D2
DTR drop causes modem to hang up. Auto-answer is
inhibited
&D3
DTR drop causes modem to do soft reset. &Y setting
determines which profile is loaded.
&F
Loads factory profile
&G0
Disables guard tone
&G1
Disables guard tone
&G2
Enables 1800 Hz guard tone