> 2.13.2 | Sending Fax

> This section comprises the subsections Description, Used AT Commands, Flow Chart, Hints and Example. To move to these subsections please use the Navigation Frame or the appropriate buttons on the toolbar.

> 2.13.2.1 | Description

> This chapter describes the steps required to send a fax document. To send a fax with a module a fax application is needed (e.g. WinFax Pro).

> 2.13.2.2 | Used AT commands

> Class 1 and 2:

> Command | Explanation
> ATD | Mobile originated call to dial a number
> ATH | Disconnect existing connection

> Only class 1:

> Command | Explanation
> AT+FRH | Receive Data Using HDLC Framing
> AT+FTM | Transmit Data
> AT+FTH | Transmit Data Using HDLC Framing

> Only class 2:

> Command | Explanation
> AT+FET | End a page or document

> For further details about the commands see [2].

> 2.13.2.3 | Flow chart

> Figure 102: Sending Fax Class1- part1
> Figure 103: Sending Fax Class1- part2
> Figure 104: Sending Fax Class2

> 2.13.2.4 | Hints

> Not applicable.

> 2.13.2.5 | Example

> Example 1:
> After the connection has established, the so called Training Check Frame (TCF) phase starts. The TCF phase is the phase of a fax call when the sending fax transmits a sequence of zeros to the receiving fax machine at the highest common data rate negotiated during prior phases. This check determines whether the line quality is adequate to pass information at the desired rate. If the line quality is good, the receiving fax machine will receive this sequence of zeros without error. If the line quality is not good, bit errors will occur during the reception, and not all zeros will be received. In this case the negotiation will be restarted with the next lower data rate.
> Figure 105: Phase B: Parameter negotiation (Class1)
> Figure 106: Phase B+C: Start sending fax (Class 1)
> The called party has hung up, a „NO CARRIER“ is issued (see Figure 108)
> Figure 107: Phase C: End fax transmission (Class 1)
> Example 2:
> The response „CONNECT“ shows a successful fax call setup. Afterwards the result code „+FCON“, indicates that the performance test before Phase C has been passed successfully.
> In order to distinguish between fax- and data connections, „+FDIS: ...“ (DIS) is issued by the module, as soon as the fax ID of the remote fax partner has been identified. This information is processed by the software of the called modem. The own capabilities are compared to the ones transmitted by the remote partner and the biggest common parameter set is chosen for the connection.
> Figure 108: Phase B+C: Start sending fax (Class 2)
> Figure 109: Phase C: End fax transmission (Class 2)
> In Phase C the result code „+FET“ indicates the page status. The module is informed, whether another page is to be sent.
> The result code „+FPTS“ indicates the status of the received pages. „+FHNG“ shows the end of the fax connection.
> Figure 110: Phase C-E: End sending fax (Class 2)