Force Connect Mode

The voice/fax switching module may be "force connected" to a remote channel, by setting up a AutoRingDown/Hoot-and-Holler connection. Refer to Hoot and Holler Application and Auto Ringdown (Analog Only) for information on configuring this type of connection.

When the voice/fax switching module is permanently connected (force connected) to a remote channel, and the remote channel goes off-hook, the FAX port will be selected first. If the fax machine does not answer after 3 rings (no CNG tone received), the FXS port will then be selected.

In the "force connect" mode shown in the figure below the local voice/fax channel is permanently connected to a remote voice/fax channel served by another FAX interface module. Incoming calls are monitored by the voice/fax module for the presence of CNG (calling tone of a fax machine). If CNG is not detected, the call is directed to the FXS port. If CNG is detected, the call is switched to the FAX port and the FAX port is disconnected from the PSTN port.

Note: Since in the "force connect" mode the fax interface module relies on CNG for call resolution, the calling fax machine must be capable of transmitting CNG. To do that, press the START button immediately after dialing the number. Also, on some fax machines CNG is an option; be sure that this option is enabled and that paper is in the tray. Any fax machine which does NOT generate the CNG tone will be directed to the voice port. There is no provision for transferring a call from the voice port to the FAX port. Solution: initiate a return call from the fax machine on the FAX port to the fax machine that originated the message.

To initiate a telephone call to the remote end, the local user lifts the receiver off-hook. Voice connection will be established when the remote user answers the call.

To initiate a fax transmission to the remote end, the local user places the fax machine off-hook, and waits for the dial tone from the PSTN. Upon receipt of a dial tone the user dials an asterisk (*), switching the FAX port from the PSTN port to the voice/fax channel and ringing the remote fax machine. Fax transmission may start when the remote fax machine answers. If the remote port is connected to a PBX, the user can dial an asterisk (*), press the PAUSE switch (or wait for the dial tone), dial the PBX extension number, then press the START button to send the fax message.

In the "force connect" application example shown in the figure below the remote end is served by an E&M interface module connected to a PBX. It is the PBX that channels the call to the proper destination.

Note: If the E&M interface module is not properly connected to the PBX, you will hear "dead air" over the handset instead of a fast busy or other call request denial indication.