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CHAPTER 9: Modem Command Set (AT Commands)
Command
Function/Options
Sr=
n
Set register r to value
n
. See list of S-registers in
Chapter 10
.
Sr?
Display current value of register r.
T
Sets tone dial as default. Forces tone dialing until the next P dial
modifier or P command is received.
Vn
Result code format.
*V0
Numeric format.
V1
Verbal format.
W
n
Error correction message control.
*W0
Upon connection, modem reports DTE speed
only.
W1
Upon connection, modem reports line speed,
error correction protocol, and DTE speed.
W2
Upon connection, modem reports DCE speed.
X
n
Extended result codes.
X0
Disables monitoring of busy tones unless forced
by country requirements; sends only OK,
CONNECT, RING, NO CARRIER, ERROR, and
NO ANSWER result codes.
X1
Disables monitoring of busy tones unless forced
by country requirements; sends only OK,
CONNECT, RING, NO CARRIER, ERROR, NO
ANSWER, and CONNECT XXXX result codes.
X2
Disables monitoring of busy tones unless forced
by country requirements; sends only OK,
CONNECT, RING, NO CARRIER, ERROR,
DIAL TONE, NO ANSWER, and CONNECT
XXXX result codes.
X3
Enables monitoring of busy tones; sends only
OK, CONNECT, RING, NO CARRIER, ERROR,
NO DIAL TONE, NO ANSWER, and CONNECT
XXXX result codes.
*X4
Enables monitoring of busy tones and sends all
messages.