DiSEqC

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DiSEqC (Digital Satellite Equipment Control) pronounced "Die-Sec" is a special communication protocol for use between a satellite receiver and a device such as a multi-dish switch or a small dish antenna rotor. It is compatible with the actuators used to rotate large C band dishes if used with a DiSEqC positioner. It relies only on the coaxial cable to transmit both bidirectional data/signals and power.

DiSEqC is commonly used to control multiswitches and claims to be more flexible than 13/18 volt and 22 kHz tone or ToneBurst/MiniDiSEqC techniques. Despite its name, it has been used on fully analogue or only partially digital-capable (Astra Digital Radio) satellite receivers [1].

A number of variations 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 simple horizontal-panning satellite motor

DiSEqC 2.0, which adds bi-directional communications to DiSEqC 1.2

All four variations were standardised by February 1998, prior to general use of digital satellite television. They are all back compatible - a DiSEqC 2.0 receiver can control a 1.0 switch; but a 1.0 receiver cannot control motorised features. The terms DiSEqC 1.3 and 2.3 are often used by manufacturers and retailers to refer to other protocols (1.3 usually refers to USALS receivers), but these uses are not authorised by Eutelsat, the developers of the system, who now act as the protocol standards agency. Eutelsat apparently developed the system to allow satellite users in Continental Europe to switch between the more popular SES Astra 1 block of satellites and Eutelsat's own Hotbird system. As a result, the vast majority of European satellite receivers support at least DiSEqC 1.2, with the notable exception of all set top boxes manufactured under the Sky Digibox name. All supporting receivers have received certification to carry a logo specifying which variation of DiSEqC they support.