[mythtv] Current SVN DVB-S zapping problems (diseqc?)
Yeasah Pell
yeasah at schwide.com
Mon Aug 28 20:48:37 UTC 2006
Lukas Kasprowicz wrote:
> Am Montag, 28. August 2006 21:15 schrieb Yeasah Pell:
>
>>> [card1]------|---------------|
>>> [card2]------| 8 ports in |
>>> --| 2 ports out |----(port 1)------- [universal LNB]
>>> --| switch |----(port 2)-------[empty]
>>> --|---------------|
>>> cards are connected to ports where i am _not_ able to switch if it has to
>>> use 22kHz for switching low/high. These are only diseqc ports.
>>>
>> I see. How does this switch decide which input to route to which output
>> at any given time? (Forgive me for the basic questions, I'm not familiar
>> with big multi-switches like this) I don't see how it can work if both
>> cards get connected to the same LNB, since the cards will both want to
>> supply a specific voltage, as well as a specific tone presence (to
>> control polarization and band) -- and they'll conflict if they are
>> connected to the same device (unless the switch disambiguates it somehow)
>>
>
> I do not know what it is doing, too but i think it operates similar to a
> network switch (maybe). Follow the link and you get the manual of the switch
> i am using. Hope it answers all your questions ;)
>
> It is the Gigaswitch 11/8 i am using.
>
> http://www.technisat.com/download/en/man/247.pdf
>
>
> Lukas
>
Wow, that's quite a switch! From the manual, the most clear designation
on how it functions is on the very first page, which is a picture of the
top panel of the switch. It's designed to work by connecting a quad LNB
to four outputs of fixed voltage and tone (generated by the switch
itself), and as such you will of course need to have four pieces of coax
running from the "sat-position A" group of switch ports (i.e. 18V low,
13V low, 18V high, 13V high) to the 4 connections on the quad LNB.
That's what you have, right? The diagram you drew made me think you only
had one piece of coax running to the LNB, but it makes sense once you
see the switch itself.
The switch then routes the receivers to the correct fixed-setup LNB
output based on the voltage/tone/diseqc observed on that input, but
doesn't pass the tone or voltage through to the LNB of course. Pretty
slick. Looks like it even mixes in terrestrial antenna signals to boot.
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