Editing Crossbar switch (section)

== Applications ==
Crossbar switches are commonly used in information processing applications such as [[telephony]] and [[circuit switching]], but they are also used in applications such as mechanical [[Sorter (disambiguation)|sorting machines]].

The matrix layout of a crossbar switch is also used in some [[semiconductor memory]] devices which enables the data transmission. Here the bars are extremely thin metal wires, and the switches are [[fusible link]]s. The fuses are blown or opened using high voltage and read using low voltage. Such devices are called [[programmable read-only memory]].<ref>{{cite journal |first1=Yong |last1=Chen |first2=Gun-Young |last2=Jung |first3=Douglas A. A. |last3=Ohlberg |first4=Xuema |last4=Li |first5=Duncan R. |last5=Stewart |first6=Jan O. |last6=Jeppesen |first7=Kent A. |last7=Nielsen |first8=J. Fraser |last8=Stoddart |title=Nanoscale molecular-switch crossbar circuits |year=2003 |journal=Nanotechnology |volume=14 |issue=4 |pages=462–8 |doi=10.1088/0957-4484/14/4/311 |bibcode=2003Nanot..14..462C |s2cid=250853934 }}</ref> At the 2008 NSTI Nanotechnology Conference a paper was presented that discussed a nanoscale crossbar implementation of an adding circuit used as an alternative to logic gates for computation.<ref>
{{Cite web
|url=http://www.nsti.org/Nanotech2008/showabstract.html?absno=119
|title=Logicless Computational Architectures with Nanoscale Crossbar Arrays
|last=Mouttet
|first=B.
|publisher=NSTI Nanotech 2008 Conference
|date=2008-06-02
|archive-url=https://web.archive.org/web/20160304092748/http://www.nsti.org/Nanotech2008/showabstract.html?absno=119
|access-date=2008-06-02|archive-date=2016-03-04
}}
</ref>

Matrix arrays are fundamental to modern flat-panel displays. Thin-film-transistor LCDs have a transistor at each crosspoint, so they could be considered to include a crossbar switch as part of their structure.

For video switching in home and professional theater applications, a crossbar switch (or a matrix switch, as it is more commonly called in this application) is used to distribute the output of multiple video appliances simultaneously to every monitor or every room throughout a building. In a typical installation, all the video sources are located on an equipment rack, and are connected as inputs to the matrix switch.

Where central control of the matrix is practical, a typical rack-mount matrix switch offers front-panel buttons to allow manual connection of inputs to outputs. An example of such a usage might be a [[sports bar]], where numerous programs are displayed simultaneously. Ordinarily, a sports bar would install a separate desk top box for each display for which independent control is desired. The matrix switch enables the operator to route signals at will, so that only enough set top boxes are needed to cover the total number of unique programs to be viewed, while making it easier to control sound from any program in the overall sound system.

Such switches are used in high-end home theater applications. Video sources typically shared include set-top receivers or DVD changers; the same concept applies to audio. The outputs are wired to televisions in individual rooms. The matrix switch is controlled via an [[Ethernet]] or [[RS-232]] connection by a whole-house automation controller, such as those made by [[AMX LLC|AMX]], [[Crestron]], or [[Control4]], which provides the user interface that enables the user in each room to select which appliance to watch. The actual user interface varies by system brand, and might include a combination of on-screen menus, touch-screens, and handheld remote controls. The system is necessary to enable the user to select the program they wish to watch from the same room they will watch it from, otherwise it would be necessary for them to walk to the equipment rack.

The special crossbar switches used in distributing satellite TV signals are called [[multiswitch]]es.