C-4 Modem Commands, Registers, and Codes
AT COMMANDS
COMMAND
DESCRIPTION
W0
No negotiation progress messages, report
connect at DTE speed.
W1
Return negotiation progress messages, report
connect at DTE speed.
W2
No negotiation progress messages, report
connect at DCE speed.
X, X0
Modem ignores dial tone and busy signal,
enables and displays CONNECT result code.
X1
Modem ignores dial tone and busy signal;
CONNECT speed result code enabled.
X2
Modem ignores busy signal; CONNECT speed
result code enabled. (Includes dial tone
detection.)
X3
Modem ignores dial tone; CONNECT speed
result code enabled.
X4
Modem recognizes dial tone and busy signal;
CONNECT speed result code enabled.
Y, Y0
Disable long-space disconnect.
Y1
Enable long-space disconnect.
Z, Z0
Reset modem and recall User Profile 0.
Z1
Reset modem and recall User Profile 1.
+++
Escape sequence. (Allows AT commands while
online; use AT0 to go back on line.)
&C, &C0
Carrier Detect always on.
&C1
Carrier Detect follows data carrier.
&D, &D0
Modem ignores Data Terminal Ready (DTR)
option.
&D1
Go to command mode for ON-to-OFF DTR
transition.