User's Manual

2.4 Commands Not Preceded by AT
Two commands, A/ and +++, are neither preceded by the attention code AT nor followed by a carriage
return.
A/ Repeat Command
A/ repeats the execution of the last command line stored in the command buffer. If the last command line is
invalid, the ERROR result code will appear on the screen. Note that A/ cannot be preceded by AT; if it is,
ERROR will appear on the screen.
+++ Escape
+++ followed by AT <CR> allows the modem to escape from the data mode to the on-line command state
(command state without breaking the established connection.)
To escape, stop transmitting data, wait at least one escape guard time (the default time is one second), and
then enter three consecutive escape characters (the default character is +) followed by AT <CR>.
The modem will return to the command state and send the OK result code to the screen. Note that the
escape command is the only command that can be recognized by the modem in the one-line state; it cannot
be recognized in the command state.
2.5 Result Codes
The modem sends a response to the user via the screen after a command is issued. As shown in the figure
below, there are two forms for each result code: Modem Response code and digit code.
Modem Response Digit Description
OK 0 Command executed without errors
CONNECT 1 Connect to another modem
RING 2 Detect an incoming ring
NO CARRIER 3 Carrier lost or never detected
ERROR 4 Invalid command or invalid character
CONNECT 1200 5 Connection established at 1200 bps
NO DIALTONE 6 Dial tone not detected within timeout
BUSY 7 Detected a busy tone after dialing
NO ANSWER 8 No ringback or quiet answer was detected by the modem
CONNECT 600 9 Connection established at 600 bps
CONNECT 2400 10 Connection established at 2400 bps
CONNECT 4800 11 Connection established at 4800 bps
CONNECT 9600 12 Connection established at 9600 bps
CONNECT 7200 13 Connection established at 7200 bps
CONNECT 12000 14 Connection established at 12000 bps
CONNECT 14400 15 Connection established at 14400 bps
CONNECT 19200 16 Connection established at 19200 bps
CONNECT 38400 17 Connection established at 38400 bps
CONNECT 57600 18 Connection established at 57600 bps
CONNECT 115200 19 Connection established at 115200 bps
CONNECT 230400 20 Connection established at 230400 bps
CONNECT 1200RX/75TX 22 V.23 connection established:transmit at 75 bps, receive at 1200 bps
CONNECT 75RX/1200TX 23 V.23 connection:transmit at 1200 bps, receive at 75 bps
DELAYED 24 Call fails to connect and number dialed is considered 'delayed' due to
country blacklisting requirements
BLACKLISTED 32 Call fails to connect and the number dialed is considered 'blacklisted'
FAX 33 A fax modem connection is established in a facsimile mode
DATA 35 A data modem connection is established in a facsimile mode
CARRIER 300 40 Carrier detected
CARRIER 1200TX/75RX V.2344 Carrier detected
CARRIER 75RX/1200TX V.2345 Carrier detected