DiseqC

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[PDF of DiseqC applications from EUTELSAT]

(http://www.eutelsat.com/satellites/pdf/Diseqc/associated%20docs/applic_info_turner-receiver.pdf)

Some critical points from the abow doc.

"Established" functions:

The 13/18 volt level has a reasonably well established function of controlling whether an LNB is to accept the Vertically or Horizontally polarised component of the signal. Therefore, the user/installer can be presented with a menu option "Polarisation: H / V", and if he wishes to add a new Programme he should be able to find the necessary information, together with the carrier frequency, in published data. It is to be hoped that a professional installer would not be too concerned whether the menu option is presented as "Polarisation: H / V" or "Voltage: 13 / 18", etc. The 22 kHz tone was originally intended to select between "Low Band" and "High Band" transmissions, i.e. the frequency of the local oscillator in the LNB. Thus the user-interface would be expected to control a functional option presented for example as "Band: Lo / Hi", which again could be presented in published data. However, the 22 kHz tone has been used for other purposes (particularly for operating a switch to select between signals from two satellites at different orbital positions), so users have been presented with a "transport" option selection such as "22 kHz: ON / OFF", rather than a "functional" option. The installation process has thus already become so inconsistent that it cannot be easily handled by reference to simple tables of transponder (Channel) information.

        "Voltage"          "13" / "18"
        "22 kHz tone"      "OFF" / "ON"
        "Tone Burst"       "A" / "B" (unmodulated / modulated)
        "Band" (Loc.Osc.)  "Low" / "High"

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SMATV

In the past, some SMATV systems have used the normal voltage and tone control signals for switching between inputs, even though these inputs may not have been directly related to the equivalent functions in an LNB.

DiSEqC also offers another set of commands which can be used for SMATV systems with up to 16 inputs. Since these commands, to the "Uncommitted" switches, are completely independent.

the difference between the Uncommitted and Committed commands is ’39h’ command byte in place of ’38h’,

There are three different types of command capable of controlling the individual "Committed" and "Uncommitted" Port-pins. These are the individual Port-bit ’set’ and ’clear’ commands (’20h’ to ’2Fh’), the Write Port- Group commands (’38h’ and ’39h’) and the "Analogue" Write-Port command (’48h’).

One-way DiSEqC operation is necessary if the slave accessories do not support reply-signalling, or if the master Tuner-Receiver/IRD is unable to detect the reply modulation.

I.E

"Standby Off" : E0 10 03 (No reply, address 10h, command 03h)

"Port Group data X" : E0 10 38 FX (As above, command 38h, data FX)

"SwitchNumber" "SwitchOption" "SatellitePosition" Polarisation Frequency "Port Group" 1 A A V Lo F0 2 A A V Hi F1 3 A A H Lo F2 4 A A H Hi F3 5 A B V Lo F4 6 A B V Hi F5 7 A B H Lo F6 8 A B H Hi F7 9 B A V Lo F8 10 B A V Hi F9 11 B A H Lo FA 12 B A H Hi FB 13 B B V Lo FC 14 B B V Hi FD 15 B B H Lo FE 16 B B H Hi FF

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DiSEqC functions:

"Polarisation" "Vertical" / "Horizontal" "Position" "1" / "2" / "3" / "4" "SMATV" "0" (off) / "1" / "2" / . . . . . . . / "16"