Switching Mode

When in the switching mode, incoming calls from the network are directed to the appropriate port, FXS or FAX, by extension number. In the example in the following figure, dialing extension 1235 from the remote end would direct the call to the FAX port. The FAX port, if idle, would be switched from the PSTN port to the voice/fax channel, and fax calls from the PSTN would be busied out.

Dialing extension 1234 from the remote end directs the call to the FXS port, causing the telephone to ring. The connection is completed when the user takes the telephone off-hook.

A busy signal is returned to the remote Passport 4430/50/55 unit caller if,

• the voice/fax channel is currently connected to the other of the two extensions. For example, if extension 1234 is currently using the voice/fax channel that it shares with extension 1235, then dialing 1235 from another Integration unit extension would result in a busy signal.
• the FAX port is the called extension, and the FAX port is currently receiving/transmitting fax messages on the PSTN.

To make an outgoing telephone call in the switched mode, the user at extension 1234 takes the telephone set off-hook, waits for a dial tone from the voice/fax module, then dials the desired extension number.

To send a fax message over the network,

1. The user places the fax machine at extension 1235 off-hook, waits for a dial tone from the PSTN, then dials a star (*).
2. If the voice/fax channel is not busy with voice traffic, a dial tone is received from the voice/fax module.
3. Next, the user dials the desired Passport 4430/50/55 unit extension number, waits for the acknowledge signal, then presses the START button to transmit the fax message.

Alternatively, if the fax machine is equipped with the PAUSE feature, the user at extension 1235 dials a star (*), presses the PAUSE switch, and dials the Passport 4430/50/55 unit extension number, and then presses the START button.

Note: The FAX port depends on the PSTN for initial dial tone. Therefore, the PSTN modular jack, or pins 1 and 2 of the terminal block, must be connected to a telephone switching port (Central Office line or PBX single-line station) for the FAX port to operate.