Synxcom SM9234D, User Manual

Page: 173 / 216

AT Commands
Page 173
Service Class 2 Action Commands
These commands transfer data, and punctuate sessions. They also release specific
T.30 messages. All action commands must be the last command on a command
line as indicated by the terminating <CR>.
All action commands initiate processes. The modem will not accept other
commands from the DTE until the modem issues a final result code (e.g., OK,
CONNECT). The modem will abort the process if it receives any character before
the final result code is issued.
ATD - Originate a Call
Syntax ATD....<CR>
The DCE can support a DTE command to originate a call using the ATD
command.
If this command is unsuccessful, the DCE reports an appropriate failure or error
type result code such as NO CARRIER, NO DIAL TONE, or BUSY.
If this call is successful, the typical DCE response is:
ATDnn..nn (go off-hook, dial, get CED)
+FCON (DCE detects flags)
[+FCSI: <remote ID string>]
+FDCS: <T.30 subparameter string>
OK
The DCE dials, detects call progress, and generates the CNG tone. It then waits
for a DIS frame. On detection of the first Phase B preamble (V.21 ch. 2 modulated
by 300 bps HDLC flags), it reports the “+FCON” message to the DTE. The DCE
then switches to 19200 bps.
The DCE generates a DCS frame based on the received DIS frame and on the
previously set +FDIS parameter. A +FDT command from the DTE releases the
DCE to transmit that
The DCE reports the initial received T.30 negotiation messages, including the DIS
frame and the optional CSI ID string. The +FDIS: report is followed by the OK
final result code.