A fax switch, also as fax switch or fax SWITCH designation, is one either passive or active mechanism at similar telephone connections. The fax switch differentiates fax transmissions with arriving calls at the beginning of the connection between telephone calls and and and leads it on the correct final mechanism. A fax switch is used, if several terminals, as telephone, telefax device and answering sets at a connection are operated or in a mechanism are integrated. Fax switches evaluate the Calling clay/tone (CNG) of 1100 cycles per second during the first seconds of the discussion, which a send-ready fax feeds.

Inband signaling

This kind of the information transfer is called Inband signaling and has in this application the disadvantage that the recognition can be accomplished only during the existing telephone connection. For distinction the lining up call must be thus first received, with which starting from this time for the caller connecting fees result.

Types of fax switches

active switch

One "active fax switch "receives the lining up telephone call first quietly, thus without a telephone would ring. Into the line pseudo ring baking clay/tone or an announcement ("please to wait") will transfer alternatively. By the caller within the next seconds if regular CNG tones are recognized, then the discussion is further-placed to the receipt against the fax equipment. If no CNG tones are recognized, the discussion is handed over to the telephone, which begins to then ring.

passive switch

One "passive fax switch "waits with a lining up telephone call for the fact that the discussion is received by another equipment (telephone, answering set). Only if this began the discussion, the switch supervises the connection, whether in the first seconds of the discussion CNG tones are to be heard, in order in this case the discussion from the Telefon/AB to to separate and to the fax equipment to the receipt hand over.

Pro and cons

While the active fax switch makes the "quiet fax receipt possible", it causes additional costs for each caller, since it has to along-pay the "test time". In particular if no answering set is attached, the caller pays only for "bells". The active switch is therefore for connections suitably, with which a great many faxes deal, however hardly telephone calls accumulates.

The passive switch causes that with each call - telephone call such as fax the telephone rings. If it concerns a discussion, no impairment occurs by this fax switch. With an arriving fax the calling (or the answering sets) hears first the CNG tones of the calling fax equipment. It must wait for these. After approximately five to 10 seconds the switch switches, only then may the telephone receiver be presented. The passive switch is suitable therefore for connections on those more telephone calls arrives than faxes.

additional extensions

Different extensions of the fax switches are marked by the manufacturers by the attribute "intelligently". Among them fall for example "automatic change-over between active and passive switch, dependent on the call receipt behavior of the user" (Siemens Telfax), "passive fax switch, which catch in principle the discussion with arriving discussions of less than 10 seconds and a fax receipt attempt accomplish", "day/night change-over between more active and passive switch", "passive switch up to bell signals x-ten and then active switch" and arbitrary combinations of it.

see also: Fax

Related links

• Connect practice telephone & fax
• www.fax-anleitung.de exemplary Konfigurationstipps to equipment

Articles in category "Fax switch"

We found here 6 articles.

Related Websites

We found here 4 related websites.

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• Telephone/Fax switch - Fax Director II - Fax LineShare
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