View source for DiSEqC

{{Short description|Communication protocol for satellite receivers}}
{{Infobox protocol
| name        = DiSEqC
| image       = DiSEqC 2.0 logo.svg
| caption     = DiSEqC logo, indicating DiSEqC 2.0 compliance
| standard    = <!--international standard such as IEEE-->
| developer   = [[Eutelsat]]
| introdate   = {{Start date|1977}}
| industry    = <!--industries used (such as PC/Chemical/Multimedia)-->
| connector   = <!--connector(s) usable with protocol-->
| hardware    = <!--examples of compatible hardware-->
| range       = <!--{{convert|X|mi|abbr=on}}-->
| newer       = <!--superseded by which protocol-->
| website     = <!--URL to specs; OD wrap in template -->
}}
[[File:Diseqc-switch.jpg|thumb|2-way DiSEqC switch]]
[[File:Commutateur-diseqc4x1-switch.jpg|thumb|4-way DiSEqC switch with attached coaxial cables.]]

'''Digital Satellite Equipment Control''' ('''DiSEqC''') ({{IPAc-en|ˈ|d|aɪ|s|ɛ|k|,_|d|aɪ|ˈ|s|ɛ|k|s|i}}{{citation needed|date=August 2012}}) is a [[communication protocol]] between a [[satellite]] [[receiver (radio)|receiver]] and a device such as a multi-dish [[switch]] or a small<ref>The maximum dish size that can generally be used with a DiSEqC motor is 1.2m; however, using a V-box as in interface, DiSEqC 1.2 can be used for very large dishes using 36V motors.</ref> dish [[Rotor (antenna)|antenna rotor]]. DiSEqC was developed by European satellite provider [[Eutelsat]], which now acts as the standards agency for the protocol.

==History==
Eutelsat apparently developed the system to allow satellite users in [[Continental Europe]] to switch between the more popular [[SES (company)|SES]] [[Astra (satellites)|Astra]] satellites at [[Astra 19.2°E|19.2° east]] and Eutelsat's own [[Hot Bird]] system at 13° east. As a result, the vast majority of European satellite receivers support DiSEqC 1.0 or higher, with the exception of all set top boxes manufactured under the Sky [[Digibox (Sky Digital)|Digibox]] name. All supporting receivers have received certification to carry a logo specifying which variation of DiSEqC they support.

==Protocol==
DiSEqC relies only upon a [[coaxial]] cable to transmit both [[Duplex (telecommunications)|bidirectional]] [[data]]/[[signal]]s and [[electrical energy|power]]. DiSEqC is commonly used to control switches and motors, and is more flexible than 13/18&nbsp;Volt and 22&nbsp;kHz tone or ToneBurst/MiniDiSEqC techniques. DiSEqC is also compatible with the actuators used to rotate large [[ Television receive-only |C band]] dishes if used with a DiSEqC positioner. DiSEqC uses a pulsed (tone-burst) 22&nbsp;kHz sine-wave at 0.65&nbsp;V (± 0.25&nbsp;V)<ref>{{cite web|url=http://www.eutelsat.com/files/live/sites/eutelsatv2/files/contributed/satellites/pdf/Diseqc/Reference%20docs/bus_spec.pdf|title=Digital Satellite Equipment Control (DiSEqC) Bus Functional Specification (Version 4.2)|work=Eutelsat|date=1998-02-25|accessdate=2012-04-18}}</ref> peak to peak.

The "Di" (digital) part of the name refers to the digital nature of the signals used by the protocol and does not imply anything about the transmission that the dish is used to receive; DiSEqC may be used with both digital and analogue satellite systems.

==Versions and compatibility==
A number of versions of DiSEqC exist:
* DiSEqC 1.0, which allows switching between up to 4 satellite sources
* DiSEqC 1.1, which allows switching between up to 16 sources
* DiSEqC 1.2, which allows switching between up to 16 sources, and control of a single axis satellite motor
* DiSEqC 2.0, which adds bi-directional communications to DiSEqC 1.0
* DiSEqC 2.1, which adds bi-directional communications to DiSEqC 1.1
* DiSEqC 2.2, which adds bi-directional communications to DiSEqC 1.2
* DiSEqC 3.0, which adds remote management of receivers to DiSEqC 2.2 to enable broadcast house uses 

First four variations were standardized by February 1998, prior to general use of digital [[satellite television]]. The later versions are backwards compatible with the lower revisions, but the lower revisions are, as might be expected, not forwards compatible with the higher revision numbers. 1.x and 2.x versions are both backwards and forwards compatible.

The terms DiSEqC 1.3 and 2.3 are also often used by manufacturers and retailers to refer to the use of DiSEqC with other protocols. For example, 1.3 usually refers to a receiver which uses [[Universal Satellites Automatic Location System|USALS]] in conjunction with the DiSEqC 1.2 protocol. Such terminology has not been authorised by [[Eutelsat]].

The following table shows compatibility between the various DiSEqC versions:

{|  class="wikitable"
|-
!
! 1.0 switch
! 1.1 switch
! 1.2 motor
! 2.0 switch
! 2.1 switch
! 2.2 motor
! 3.0 receiver
! 3.0 antenna-side
|-
|1.0 receiver||{{yes}}||{{no}}||{{no}}||{{yes}}||{{no}}||{{no}}||{{yes}}||{{no}}
|-
|1.1 receiver||{{yes}}||{{yes}}||{{no}}||{{yes}}||{{yes}}||{{no}}||{{yes}}||{{no}}
|-
|1.2 receiver||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{no}}
|-
|2.0 receiver||{{yes}}||{{no}}||{{no}}||{{yes}}||{{no}}||{{no}}||{{yes}}||{{no}}
|-
|2.1 receiver||{{yes}}||{{yes}}||{{no}}||{{yes}}||{{yes}}||{{no}}||{{yes}}||{{no}}
|-
|2.2 receiver||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{no}}
|-
|3.0 broadcast house||{{no}}||{{no}}||{{no}}||{{no}}||{{no}}||{{no}}||{{yes}}||{{yes}}
|-
|3.0 antenna-side||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}||{{yes}}
|-
|}

NOTE: a 1.x receiver will not be able to receive communication from a switch or motor. Usually this is not important, as the switch or motor can be controlled by the receiver without problems.

==See also==
* [[Universal Satellites Automatic Location System|USALS = Universal Satellites Automatic Location System]]
* [[Monoblock LNB]] - [[Low-noise block downconverter|LNB]] with builtin DiSEqC switch, used for multiple streams on a single dish
* [[Sat-IP|SAT&gt;IP]] - A modern alternative to DiSEqC which uses an IP-based network to deliver multiple DVB streams
*[[SES (company)|SES]]
*[[Astra (satellites)|Astra]] 
*[[Eutelsat]]
*[[Astra 19.2°E]]
* [[Automatic Tracking Satellite Dish]]
* [[Starlink#User terminals|Starlink Dish]]

==Notes==
<references />

==External links==
* [https://www.eutelsat.com/en/support/technical-support-teleports-resources-tools.html?#resources DiSEqC specifications]
*[https://blog.solidsignal.com/wp-content/uploads/2019/04/bus_spec.pdf DiSEqC specs (retrieved from Internet Archive)]
*DiSEqC Bus Functional Specification Version 4.2 ([https://www.eutelsat.com/files/PDF/DiSEqC-documentation.zip bus_spec.pdf contained in DiSEqC-documentation.zip])
{{DEFAULTSORT:Diseqc}}

{{Satcomm|state=uncollapsed}}
{{Telecommunications}}

[[Category:Television technology]]
[[Category:Satellite television]]