DiSEqC
Digital Satellite Equipment Control DiSEqC short [ daɪsɛk ] refers to a digital control signal technology used in building wiring of satellite reception systems ( satellite block distribution or unicable technology). DiSEqC control signals allow over the 14/18-Volt- and 22 kHz control signals used when satellite reception extended functionality.
History
With the introduction of the Astra satellite system at the beginning of 1990, a need for easy to install satellite systems emerged. At this time, mechanical or magnetic Polarizer were common in satellite reception. This required separately for coaxial cable routed control cables; There was also coaxial leading control lines in the shield. To select the desired polarization accurate fine tuning was ( the so-called skew ) is required at the receiver for each satellite program. Alternatively, it was also common (ie two separate ) to move each satellite block - level has own coaxial cable.
- Marconi LNB: In English improvement stores then appeared satellite systems on the Do it yourself fitment to receive the English Astra programs. This realized the polarization switching by simply changing the LNB supply voltage; separate control lines accounted for, the installation of the receiving equipment was therefore easy.
- Marconi LNB 22 kHz control: Switchable By superimposing the LNB supply voltage with a 22 - kHz signal has four switching states at the LNB could be realized. This was enough to switch to Astra - receiving equipment to those two newly added digital satellite block -level ( high- level).
- Eutelsat and the DiSEqC standard: After the introduction of the high frequencies no other, second satellite could be received by a single receiver more. However, since Eutelsat German households would be directly supplied with satellite signals, additional switching options for controlling several satellite dish had to be implemented in new receiver. For Eutelsat developed in collaboration with Philips in the early 1990s the DiSEqC standard.
Using DiSEqC can be transmitted even complex control commands from the receiver to the LNB; so DiSEqC is the basis for the satellite block distribution alternative SAT - IF distribution ( unicable ). Satellite systems in a consistent DiSEqC technology will be able to do without changing a LNB supply voltage.
In October 2011, the Federal Court dismissed the appeal of the company SuperSat against the deletion of claims on the DiSEqC proceedings before the Federal Patent Court back ( AktZ.: X ZR 94/ 09).
Technology
DiSEqC is a for each open, royalty-free industry standard. The DiSEqC switch commands are transmitted serially as digitally coded data words. The DiSEqC data word consists of a start character, an address byte and a command byte, which still may be followed by additional data byte. The transmission of words is done by switching on and off ( modulating ) the existing 22 kHz switching signal. The integrity of data transmission is ensured by a parity bit after each byte received. DiSEqC is in version 1.x unidirectional ( commands only from the receiver to the functional part ) in version 2.x bidirectional. The version number indicates the extent of its functions:
- V1.0: switching operations for four satellite positions ( PosAOptA, PosAOptB, PosBOptA, PosBOptB ), two bands (low, high ) and two polarizations (horizontal, vertical), a total of 16 switching states
- V1.1: four additional options (hence 64 possible satellite positions and a total of 256 switching states, which rarely available receiver with v1.1 support, however, usually only 16 satellite positions, for a total of 64 switching states ) (to be backward compatible with v1.0 )
- V1.2: additional option for rotor control ( not backward compatible with v1.0 and v1.1, but support almost all receivers with v1.2 in practice v1.0 )
- V2.0: bi-directional communication with the switching states of the v1.0 ( does not contain as widely believed automatically v1.1 and v1.2 )
- V2.1: control of the receiver via the receiver cable possible; 4 other switch addresses
- V3.0: additional programming options ( not yet widespread, with this standard, however, can easily implement individual unicable single-cable to combine with one another as without new and expensive headends numerous IF signals)