Editing Terminal adapter

A '''terminal adapter''' or '''TA''' is a device that connects a terminal device – a computer, a mobile communications device, or other – to a communications network.<ref name=":0">{{Cite web |last=Rouse |first=Margaret |date=September 28, 2011 |title=Terminal Adapter |url=https://www.techopedia.com/definition/3015/terminal-adapter-ta |access-date=October 22, 2024 |website=Techopedia}}</ref>

== ISDN ==
In [[ISDN]] terminology, the ''terminal adapter'' connects a ''terminal'' (computer) to the ISDN network. The TA therefore fulfills a similar function to the ones a [[modem]] has on the [[Plain old telephone service|POTS]] network, and is therefore sometimes called an '''ISDN modem'''.  The latter term, however, is partially misleading as there is no [[modulation]] or [[demodulation]] performed.

There are devices on the market that combine the functions of an ISDN TA with those of a classical modem (with an ISDN line interface).  These combined TA/modems permit connections from both ISDN and analog-line/modem counterparts.  In addition, a TA may contain an interface and [[codec]] for one or more analog telephone lines (aka ''a/b line''), allowing an existing POTS installation to be upgraded to ISDN without changing phones.<ref name=":0" />

Terminal adapters typically connect to a [[basic rate interface]] ([[S interface|S0]], sometimes also  [[U interface|U0]]).  On the ''terminal'' side, the most popular interfaces are [[RS-232]] serial and [[USB]]; others like V.35 or [[RS-449]] are only of historical interest.

Devices connecting ISDN to a network (e.g. [[Ethernet]]) commonly include [[router (computing)|routing]] functionality; while they technically include a TA function, they are referred to as (ISDN) [[router (computing)|router]]s.

==Mobile networks==
In [[mobile network]]s, the ''terminal adapter'' is used by the [[terminal equipment]] to access the [[mobile termination]], using AT commands (see [[Hayes command set]]).

In [[2G]] (such as [[GSM]] or [[CDMA]]), the terminal adapter is a theoretically optional while in [[3G]] (such as [[W-CDMA]]), the terminal adapter is mandatory and is part of the mobile termination.<ref name=":0" />

==Automation industry==
In the [[automation]] industry, a ''terminal adapter'' is a ''passive'' device that converts a connector like the [[8P8C]] (RJ-45) [[modular connector]] or [[DE-9 connector|9 pin D-Sub]] into a [[terminal block]] to facilitate wiring.  It is often used when [[daisy chain (electrical engineering)|daisy chain]] wiring is necessary on a multi-node serial communication network like [[RS-485]] or [[RS-422]].<ref name=":0" />

== References ==
<references />

==See also==
*[[Federal Standard 1037C]]

{{DEFAULTSORT:Terminal Adapter}}
[[Category:Integrated Services Digital Network]]