Modem Commands A-2
AT Commands (cont’d)
Command
Description
Default
O0 Go into online data mode without retrain
sequence
O1 Go online data mode with retrain sequence
P Set pulse dial
Q0 Enable result code X
Q1 Disable result code
Sn=m Write m to S-register n
Sn? Return the value of S -register n
T Set dial tone
V0 Set numeric result code
V1 Set verbose result code X
W0 CONNECT reports DTE speed X
W1 CONNECT reports DTE speed, carrier
speed and protocol
W2 CONNECT reports carrier speed
X0 Report CONNECT message only
Ignore dial tone and bus y signal
X1 Report CONNECT message according to
ATW
Ignore dial tone and bus y tone signal
X2 Report CONNECT message according to
ATW
Ignore busy signal
X3 Report CONNECT message according to
ATW
Ignore dial tone
X4 Report CONNECT message according to
ATW X
Y0 Disable long space disconnect X
Y1 Enable long space disconnect
Z Soft reset
&C0 CD is always on
&C1 CD follows the stat e of carri er X
&D0 Ignore DTR