What is DiSEqC? (Description)

What is DiSEqC?

DiSEqC (Digital Satellite Equipment Control) - a special communication protocol for exchanging data between a satellite receiver and other devices - such as switches, polarizers, positioners, etc. To signal a coaxial cable. Communication mode via cable - single or double, to supply power. The standard provides compatibility with traditional dual voltage 13/18 V and 22 kHz tone.



DiSEqC protocol is used to control various peripherals in the reception of satellite TV systems. This positioners, switches, and even converters (LNB), who did not become popular (we are talking about managed protocol converters 1.0). DiSEqC commands transmitted over the DC voltage by 12-20 tone chip 22 kHz (± 20%) and a nominal amplitude of 650 mV (± 250 mV) when the supply voltage 13/18 V. Given cable loss and permissible error DiSEqC-detector device must be capable of operation at lower amplitude to 300mV. Maximum recommended range is 1V. In order that the detector does not react to the noise, it does not have to respond to the tone sending amplitude of less than 100mV.

        DiSEqC uses to transmit a pulse width manipulation, in which the width of the envelope of the pulse depends on the transmitted bits. Time per bit is 1.5 ms, and is conventionally divided into 3 equal pieces of 500 ms (± 100 ms). Bit 0 for the width of the envelope is 1.0ms, corresponding to 22 pulses, and for bit 1, the width of the envelope is 0.5 ms, and is 11 pulses.

       The standard defines several levels at which the device can operate DiSEqC. Each level requires a set of generated / executed commands and features. The idea is that the levels are compatible "down", that is, a receiver with a higher level of support required to work with the peripheral lower level. In fact, this rule does not always happen. For example, almost all modern digital receiver supports DiSEqC 1.2 (work with positioner) and does not support DiSEqC 1.1 (work with an expanded set of switches). Another exception to the rule: any receiver that supports DiSEqC 1.0, the switch must support and Tone Burst - in fact, a good half of receivers can not work with this switch.

There are several options for DiSEqC: The lowest level - mini-DiSEqC or Tone Burst. It does not have a "digital" signs and, in fact, is not part of the technology DiSEqC, but Tone Burst device can operate in the same system with the "real" devices DiSEqC. Therefore, the standard defines this level as «DiSEqC-compatible» - compatible with DiSEqC.
DiSEqC 1.0 - allows you to switch between the four satellites;
DiSEqC 1.1 - allows you to switch between the 16 satellites;
DiSEqC 1.2 - allows you to control the positioner;
DiSEqC 2.0 - added two-way communication mode to DiSEqC 1.0.

The four variations of the standard have been standardized in February 1998, before the widespread use of digital satellite TV.

          Levels DiSEqC 1.X suggest a one-way communication - just send commands from the receiver peripherals. Levels DiSEqC 2.x provide for the transfer, as teams from the receiver peripherals and responses of these devices receiver. In addition, depending on the set of generated / execution units, and, consequently, the set of supported devices, these levels are divided into three sub-layers: DiSEqC H.0, DiSEqC DiSEqC X.1 and X.2. Here there is often confusion. For example, it can be assumed that the level above the DiSEqC 2.0 DiSEqC 1.1, and a receiver that supports DiSEqC 2.0, should work, for example, the switch DiSEqC 1.1. In fact, DiSEqC 2.0 - is a "bi-directional version of the" level of DiSEqC 1.0, and includes only the instruction set level of 1.0.

          Level DiSEqC 3.0 standard in documents only mentioned but not described. The system not only DiSEqC 3.0 peripheral devices to be controlled from the receiver, but they themselves receivers can be programmed and adjusted signals DiSEqC, coming from a single control center. This technology is relevant for collective systems with multiple receivers. Actual devices that support DiSEqC 3.0, there was no market. In other words, the level of today is not implemented, and treat it early.

DiSEqC ™ - trademark of «Eutelsat».

          Some variations of DiSEqC is often used by manufacturers and stores to refer to other protocols (1.3, usually receivers «USALS»), but these species are not authorized «Eutelsat».