Comtrol AT Commands for SmartACFL - Manual (Page 128)

Command Reference Manual
5-6 Conexant 100722A
5.3.3 +FDT - Data Transmission
Syntax: +FDT <CR>
The +FDT command prefixes Phase C data transmission. When the DCE is ready to accept Phase C data, it issues the
negotiation responses and the CONNECT result code to the DTE.
In Phase B, the +FDT command releases the DCE to proceed with negotiation, and releases the DCS message to the remote
station. In Phase C, the +FDT command resumes transmission after the end of a prior transmit data stream.
5.3.3.2 Initiate Page Transmission
Phase B DCE polled response:
[+FCSI:<remote ID string>] - if new CSI received
[+FDIS:<subparameters from remote station>] - if new DIS received
+FDCS:<T.30 subparameter string>
CONNECT
<XON>
- when ready for data
After placing a call, or after finishing a document exchange, the DTE may command the DCE to re-enter T.30 Phase B to
attempt to negotiate a document transmission.
5.3.3.3 Continue a Page
CONNECT
<XON>
The DTE may issue more than one +FDT command for a given page, so that different files may be concatenated together.
These files must have the same format.
5.3.3.4 Phase C Data Framing
Phase C data must be presented to the DCE in stream mode. The DCE expects Phase C data to follow until it detects
<DLE><ETX> termination characters. The DCE will filter the stream as described in Section 6.1.2.
The DCE will acknowledge the end of the data by returning the OK result code to the DTE.
If there is data underrun before the next +FDT or +FET= command, the DCE will zero-fill the pad as per T.4 until the Phase C
timeout (+FPHCTO) is reached, or until more data is received. The DCE appends an RTC pattern to the transmit data after an
+FET= command is received from the DTE.
5.3.3.5 Phase C Data Format
The Phase C data will be of the format specified by the negotiated T.30 DCS frame. The +FDCS:<string> response is defined
in Section 6.4.2. The subparameter values are described in Table 5-2.
The DCE will use the negotiated minimum Scan Time parameter from the DCS frame, and insert sufficient fill bits to pad each
line to the minimum scan time. This is reported in the +FDCS:ST subparameter.
If the DCE finds more than one consecutive EOL in Phase C data (e.g., RTC), it will send only one EOL.
1. Phase C data must conform to T.4 specifications.
2. The DTE need not include a final RTC, since the DCE will append an RTC in response to an FET= command.
3. Some facsimile machines may treat two EOLs as an RTC.
5.3.3.6 <CAN> - Escape from Transmission
The DCE may request the DTE to halt Phase C transmission, by sending a cancel <CAN> character (024) to the DTE. In this
case, the DTE should terminate Phase C transmission, issue <CAN>, and wait for the OK response code from the DCE.