Telenetics 56 - Manual (Page 168)

AT Commands
Page 160
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.
ATA - Answer a Call
The DCE can support a DTE command to answer an incoming call using the ATA
command.
The DTE may issue an Answer command in response to an incoming ring.