AT Commands
242 Perle 833IS User Guide
AT= x - Write to
Selected S-Register This command writes the value x to the currently selected S-Register. An S-Register
can be selected by using the ATSn command. All of the S-Registers will return the
OK response if x is a number. Some registers may not be written due to country
specific PTT limitations.
Result Codes
OK For all arguments.
AT? - Read Selected
S-Register This command reads and displays the selected S-Register. An S-Register can be
selected by using the ATSn command.
Result Codes:
OK For all arguments.
A - Answer The modem will go off-hook and attempt to answer an incoming call if correct
conditions are met. Upon successful completion of answer handshake, the modem
will go on-line in answer mode. Operation is also dependent upon +FCLASS
command and country-specific requirements.
Bn - CCITT or Bell When the modem is configured to allow either option, the modem will select Bell or
CCITT modulation for a line speed connection of 300 or 1200 bps according to the
parameter supplied. Any other line speed will use a CCITT modulation standard.
B0 Selects CCITT operation at 300 or 1200 bps during Call Establishment
and a subsequent connection. (Default for W-class models.)
B1 Selects BELL operation at 300 or 1200 bps during Call Establishment
and a subsequent connection. (Default for US models.)
Result Codes:
OK n = 0 or 1.
ERROR Otherwise.
Cn - Carrier Control This command is included for compatibility only, and has no effect other than
returning a result code. The only valid parameter is 1.
Result Codes:
OK n = 1.
ERROR Otherwise.