[vdr] Re: Some questions about plugin-features of vdr-developer...

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

Christian Schuld wrote:
> 
> Hi,
> 
> On Tuesday 03 September 2002 09:13, you wrote:
> > Reiner Rosin wrote:
> [..]
> > I don't think that DiSEqC is something that should be handled by a plugin.
> > My plans are to replace the 'diseqc' parameter in the channels.conf file
> > with a more general 'source' parameter. In case of a satellite channel,
> > this would be the satellite position. Then a yet to be written function
> > cDvbDevice::SetDiSEqC() shall take the satellite position, frequency and
> > polarization and generate the necessary DiSEqC commands to set the
> > equipment to receive this channel. In doing so, it shall read a yet to be
> > specified file 'diseqc.conf', which maps the satellite position, frequency
> > and polarization to the installation specific DiSEqC setup.
> >
> > Of course this needs to go into the core cDvbDevice implementation.
> > If you can come up with a useful implementation of a
> > cDvbDevice::SetDiSEqC(), please let me know.
> 
> Please keep in mind that you can have DiSEqC setups with e.g. cascading
> switches or rotors etc, which have to be considered when designing
> cDvbDevice::SetDiSEqc().
> 
> Lets take my setup as an example. I have a "Stab" sat rotor on position 2 of a
> DiSEqC 4/1 switch and a second dish pointing to Astra on switch position 1.
> So if I want to move the rotor, I have to send a diseqc-cmd to the switch (to
> select pos.2) first and then send the appropriate diseqc-cmd to the rotor.
> 
> A problem with rotors generally is, that they need quite a few seconds to
> reach a new position. My rotor moves at a speed of 1,8°/s, so it takes f.e.
> about 43 seconds to move from 42°W to 36°E. cDvbDevice::SetDiSEqc() have to
> be able to retune the channel, because on the move the frontend might lock to
> a wrong satellite or loose the frequency because of the zigzag- scan.
> 
> Another problem with my rotor is, that it only moves when tuned to horizontal
> channels, so when it gets 18V. But I don't know if this is a limitation of
> the DVBs or my special setup.
> 
> The EPG handling needs to be adjusted, too, when using multiple satellites,
> because then you don't have unique ServiceId any more.

Yes, I'm aware of that. This will be taken into account when the DiSEqC (or rather
"source" handling) mechanisms will be rewritten.

As for the rotor handling: I guess we could have some notation that let's you
specify a string like the good old AT modem codes, where you can specify any
sequence of voltage, tone, DiSEqC commands, timeouts etc. However, I'm not sure
how the cDvbDevice could "know" when the rotor has reached its target position.
Is there some feedback for this?

Klaus
-- 
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Klaus Schmidinger                       Phone: +49-8635-6989-10
CadSoft Computer GmbH                   Fax:   +49-8635-6989-40
Hofmark 2                               Email:   kls@cadsoft.de
D-84568 Pleiskirchen, Germany           URL:     www.cadsoft.de
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