VEGA Phoenix PSI Data Fax Modem - Manual (Page 95)

AT Commands
692302 6-7
+++ Escape String
The escape string can be used to switch your modem from data mode to command
mode without losing the connection with the partner. When you enter the escape
string, your modem outputs an OK message to inform your that it is in command
mode.
Enter ATO to return to data mode and confirm by pressing ENTER. Enter ATH to
hang up and confirm by pressing ENTER.
H Hook (Hang Up)
I Identification
L Volume Control
M Speaker
H0 The modem hangs up.
I0 Display the ID number for your modem.
I1 Display the ROM checksum for your modem.
I2 Execute a memory test and output an OK message if the test was
successful.
I3 Display the V.42bis ID number for your modem.
I4 Display the internal ID for your modem.
I8 Display the serial number for your modem.
L0 Low volume
L1 Low volume
L2 Medium volume
L3 High volume
M0 Speaker off
M1 Speaker on during the connection phase
M2 Speaker always on