TechniSat TechniRouter 5/1x8 K - Handbuch (Seite 43)

43
EN
SCR commands can be divided into the following groups:
Channel Change
With this command, the router will be told which SAT IF bank should
be switched to and which channel is to be converted to the user band
frequency.
PowerOff This command prompts the router to switch off the affected user
band.
Installation
There are a number of commands meant to simplify installation of an
SCR system. Thus a receiver can query what kind of router, LNB or
multi-switch, it is connected to, and which LO frequencies are used.
The router answers with an RF signal tone within the affected user
band. In addition, the signal tones for all participants can be activated
simultaneously. This allows receivers to search for the user bands
automatically.
Because there is no bus access control in this system, there can be collisions between
commands sent by more than one receiver at the same time. This problem is solved by the
receivers recognizing the collision and repeating their commands after an ideally random delay.
7.3 PIN Protection
In distribution systems that have the cable connected to more than one dwelling (Multiple
Dwelling Units, MDU), the SCR commands can optionally be provided with a PIN code. The
command is only accepted if the PIN code matches the one stored in the router. This should
prevent, for example, a misconfiguration from having more than one receiver use the same user
band.
PIN protection can only be used if the installed router supports it. Receivers without PIN support
are usable though. However, commands with PIN codes always have priority.
TechniRouter 5/1x8 and 5/2x4 don’t have the PIN code feature.
7.4 Assembly Instruction
As far as the cabling is concerned, besides the series structure, in which all antenna outlet
sockets are on a single coaxial cable harness, tree structures, star structures and combinations
of all three are possible. The important thing is that every single receiver feeds its control
commands via a separation diode into cable sections of the SCR bus shared with other receivers.
This, in combination with the bus voltage being raised to 18V during SCR commands, is the only
way to ensure that these arrive at the router and are detected within.
Generally, antenna outlet sockets with integrated separation diodes have to be installed.
If one connects multiple receivers to a shared antenna outlet socket, distribution elements with
diode-separated DC paths must be provided.
In contrast to omitted separation diodes, multiple cascaded diodes don't generally impair the
system's functionality. However, in router installations not utilizing an external power supply
attention has to be paid to the resulting lower bus voltage due to voltage drops at the diodes,
whether it is still sufficient for stable operation of router and LNB.