User's Manual Part 1

64 AT Commands
Revision 1.8 P/N 90023363
Syntax: ATL[<n>]
Parameters: 0, 1, 2, 3
where:
0 sets the speaker volume to very low
1 sets the speaker volume to low
2 sets the speaker volume to medium
3 sets the speaker volume to high
Response: This command will return the string OK.
Example: ATL3<cr>
ATM
Description: ENABLE MODEM SPEAKER
This command turns the modem’s speaker circuit on or off. When the
modem is installed in a computer, it will use the computer’s default
speaker.
This command is ignored when the modem is connected to a GSM
network.
Syntax: ATM[<n>]
Parameters: 0, 1, 2
where:
0 turns the speaker off
1 turns the speaker on until the modem informs the terminating
equipment that a carrier has been detected
2 turns the speaker on while the modem is off-hook
Response: OK
Example: ATM1<cr> OK
ATO
Description: OPEN DATA MODE
This command switches the modem from command mode to data mode.
This command is generally used to return the modem to data mode after
the user has issued the command +++AT and worked in the modem’s
command mode.
Syntax: ATO[0]