User's Manual

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Appendix II
AT Commands
AT COMMAND SYNTAX
The "AT" or "at" prefix must be set at the beginning of each command line and enter
<CR> is used to terminate a command. Commands are usually followed by a response as
"<CR><LF><response><CR><LF>".
 Parameter […]
Specify user-definable parameter values, which may be <text> or <number>.
 (ERR_STR)
If a connection fails, the response may include a string after the message, e.g. “NO
CARRIER”, providing further information on the connection error.
 [ERR_CODE]
If a connection fails, the response will always include a 6-digit hexadecimal number
(always starting with “0x”). Refer to the Error Codes table for more information.
Note: If you are programming in BASIC language, the delimiter 0x0d (CR) is in use by
default. Refer to COM_DELIMITER().
The escape sequence consists of three characters “+++”. Once a connection has been
established, type the escape sequence to return to command state. When entering the
next command after an escape sequence, always wait to receive “\r\nOK\r\n”. The
escape sequence only works after dialing out and establishing the connection.
Note: The escape sequence will break the connection.
There are equal guard time before (leading) and after (trailing) the escape sequence
command, as illustrated below.
If the escape sequence is not followed by another command within 1 second (trailing
guard time), the cradle will hang up immediately. Normally, the mobile computer will
receive the message “OK” unless the line is abnormally busy.
Note: The Guard Time is 1 second and cannot be changed.