For Specialists: Digital Single-Cable Systems According To En 50494; How It Works; Control Signals - TechniSat TechniRouter series Montageanleitung

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For Specialists: Digital Single-cable Systems according to EN 50494

7.1 How It Works

A problem in traditional satellite TV distribution systems is that they have to refer back to a star
EN
distribution in order to provide each receiver with signals from all SAT IF banks. Therefore, a
coaxial cable must be installed from each receiver to the LNB or multi-switch, with TWIN
receivers even two. This makes it very costly to upgrade existing cable structures to satellite TV, if
not impossible. With a new method standardized according to DIN EN 50494 it is now also
possible to provide existing cable systems with satellite signals, without limitation to the number of
channels. In this case, each connected receiver is assigned a fixed user band.
Besides selecting the desired SAT IF bank, the LNB, or multi-switch, now also has the task of
converting the desired TV signal to the user band frequency.
Thus the name satellite channel router (SCR).

7.2 Control Signals

For controlling the router, special DiSEqC-related SCR commands are used. However, in contrast
to DiSEqC, the voltage is permanently 13V and is only raised to 18V during the actual command.
18V
13V
In coordination with the receiver's diode-separated connection, this ensures that the receiver
sending the command has exclusive access to the common cable. As introduced with DiSEqC, a
22kHz tone is modulated to transmit commands as digital data.
Each command contains the user band number as a kind of sender ID for the sending receiver.
HLo
2 3
VLo
HHi
4
VHi
1 2
Userband
6 5
7
1
3 4 5 6 7
42
8
8
Frequenz
Zeit