User's Manual

&Z – Telephone Number Storage
The modem can store up to 4 telephone numbers by using the AT&Zn=x
command (n= 0-3). These can be dialed automatically by the command
ATDS=n. Telephone numbers must not be more than 45 characters in length
(digits + dialing parameters).
For example: AT&Z2=T06897 123456
The telephone number T (tone dialing) 06897 123456 is stored in memory 2.
+MS – Select Modulation
This command sets the type of modulation used and the send and receive
speeds. Settings for Bn, +MS=m, Nn and S37 determine the allowable modem
connections. Nn performs the same function as the +MS=m <automode>
parameter. S37 performs the same function as the +MS=m <max rate>
parameter.
V.34 modulation connections can be symmetrical or asymmetrical. In
symmetrical connections, the transmit and receive speeds are the same; in
asymmetrical, they are different. Modems can be configured by the +MS=m
command to support only asymmetrical or symmetrical connections. The
factory default is for a 33,600-bps asymmetrical connection. Note that the
transmitter speed and receiver speeds typically are different for most V.34
connections over the PSTN.
The +MS command sets the modulation speeds in the V.34 chipsets; however,
to set the modulation to either V.22 or Bell 212, the B0 or B1 command also
must be sent. To set the modulation type to ITU-T V.22, send the B0
command; to set the modulation type to Bell 212, send B1. These commands
can be typed before or after the +MS command. For example, to set the
modulation to ITU-T V.22:
+MS = V22, 1, 1200, 1200; B0
To check the settings for the +MS command, type AT+MS?
m=<carrier>, <automode>, <min rate>, <max rate>
Defaults: m= V90, 1, 0, 0
<carrier> The eight-digit string parameter specifies the type of modulation
used. Approved codes are shown in the following table. The modem can
switch automatically between some types.
<carrier> Description
V21 V.21 300 bps
V22 V.22 1200 bps
V22B V.22 bis 1200 and 2400 bps
AT COMMANDS: DATA MODEM 2-13