Sharp UX-600M operation manual How fax transmissions are detected

Chapter 7 Answering Machine Hookup

How fax transmissions are detected:

Your fax detects fax transmissions in two ways when an answering machine is connected, depending on whether the document is being sent automatically or manually:

Automatic dialing: If the document is sent using a form of automatic dialing, such as Rapid Key or Speed Dialing, the transmitting fax machine will send a "calling tone" at 3-second intervals for a period of about 30 to 40 seconds after dialing. When your fax detects this tone, it will disconnect the answering ma- chine, send a "reception tone" in response, and begin receiving the transmission.

If the transmitting fax does not receive a reception tone from your fax within 30 to 40 seconds after dialing, it will usually hang up and automatically redial sev- eral minutes later.

Since your fax may not be able to detect the transmitting fax’s calling tone until after the outgoing message ends, it is important that the answering machine an- swers the call within two rings and the outgoing message is less than 10 sec- onds. Otherwise, your fax may not be able to establish communication with the transmitting fax before the latter hangs up.

Manual dialing: If the document is being sent by normal (manual) dialing, the transmitting fax machine does not send a calling tone. Instead, the person faxing normally waits until they hear a reception tone and then presses their Start key. In the case of an answering machine hook-up, they will hear your outgoing mes- sage instead of a reception tone, and then press their Start key.

However, this does not signal a fax transmission to your fax. Instead, your fax must use a function called "Quiet Detect Time" to detect the transmission. This function causes your fax to disconnect the answering machine and begin recep- tion if it detects a certain duration of silence.

Your fax is set to automatically begin fax reception if it detects a duration of si- lence of four seconds. When the person faxing presses their Start key, the line will go quiet, and the transmitting fax machine will wait for a reception tone from your fax. Your fax will disconnect the answering machine four seconds af- ter the key is pressed, and send a reception tone to tell the other fax machine to begin transmission.

If your answering machine has a fast disconnect time and disconnects the line before four seconds elapses, fax reception will not be possible. In this case, you must shorten the Quiet Detect Time setting as described on the following page. On the other hand, if the Quiet Detect Time setting is too short, your fax may in- terrupt voice callers if they pause during their message or if there is a period of silence in your outgoing message.

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