Comtrol AT Command Set Rev A - Manual (Page 174)

AT Commands Reference Manual
Conexant 100722B
5-2
5.1 Command and Syntax Guidelines
5.1.1 Mode Entry Commands
+FCLASS=2 - Select Facsimile Class 2 Mode
+FCLASS=2 selects the Fax Class 2 Mode (see Section 3.2.1).
5.1.2 DTE Commands
The ISO 646 character set (CCITT T.50 International Alphabet 5, American Standard
Code for Information Interchange) is used for the issuance of commands and responses.
Only the low-order 7 bits of each character are used for commands or parameters; the
high order bit is ignored. Upper case characters are equivalent to lower case characters.
For Phase C data transmission or reception, all 8 bits are needed.
DTE Command Lines
A command line is a string of characters sent from a DTE to the modem (DCE) while the
modem is in a command state. A command line has a prefix, a body, and a terminator.
Each command line (with the exception of the A/ command) must begin with the
character sequence AT and must be terminated by a carriage return. Commands entered
in upper case or lower case are accepted, but both the A and T must be of the same case,
i.e., "AT" = ASCII 065, 084 or “at” = ASCII 097, 116. The body is a string of commands
restricted to printable ASCII characters (032 - 126). Space characters (ASCII 032) and
control characters other than CR (ASCII 013) and BS (ASCII 010) in the command string
are ignored. The default terminator is the ASCII <CR> character. Characters that precede
the AT prefix are ignored. The command line interpretation begins upon receipt of the
carriage return character.
Facsimile Command Syntax
After the "AT" or "at" prefix, facsimile commands use extended syntax. Each command
is preceded by the “+F” character and consists of single characters and a decimal
parameter (if applicable) terminated by the semicolon “:” character (ASCII 059) or by the
<CR> that terminated the command line. A missing decimal parameter is evaluated as 0.