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DiSEqC on Slave Tuners for Unicable setups

PostPosted: Wed Nov 02, 2022 9:23 pm
by LSD
Hi

Basically it makes perfect sense in a legacy LNB environment to allow only the master tuner to send DiSEqC message, but this is not the case for Unicable setups, where the slave tuner must be able to send DiSEqC messages over the same cable. Could the driver be enhanced so that it uses the master tuner to send DiSEqC messages for the slave tuner aswell?

BR
LSD

Re: DiSEqC on Slave Tuners for Unicable setups

PostPosted: Thu Nov 03, 2022 3:21 am
by crazycat
both tuners can send diseqc cmd

Re: DiSEqC on Slave Tuners for Unicable setups

PostPosted: Thu Nov 03, 2022 4:05 pm
by LSD
Hi crazycat

It's hard to argue with the developer :-), I was just refering to the manual for the 6508 where it says that it is only possible to send diseqc messages on the master tuner. So I did some testing in tvheadend and basically the driver accepts the diseqc message but it seems to never arrive at the lnb. What I did was the following:
Enable only tuner #0 and make sure everything is working as expected.
Disable tuner #0 and enable #1, now I can tune normally on the last transponder that was used with tuner #0 but everything else won't lock. I can also add a transponder with the same basic settings (SR/FEC,System...) and a completely different frequency and it will still scan the same transponder which was last used on tuner #0.

I also enabled debug/traces in tvh and made sure it does send the correct messages to the device (at least from tvheadends point of view). So although it seems everything is perfectly right, nothing seems to arrive at the output. I don't know how much you are involved in the firmware developement, but it might be discarded just there.

Re: DiSEqC on Slave Tuners for Unicable setups

PostPosted: Sat Nov 05, 2022 3:33 am
by crazycat
Ok, look like this hw limitation - 22khz wired only from first demod from each si21832 dual demod chip.
si2183 frontend driver set 22khz tone and send diseqc cmd for each demod instance

Re: DiSEqC on Slave Tuners for Unicable setups

PostPosted: Sat Nov 05, 2022 5:05 pm
by LSD
The big question now is if we need to fix this for every dvb software which is out there or if the driver can be modified to use the first demod even if it was intended for the second one?

Re: DiSEqC on Slave Tuners for Unicable setups

PostPosted: Mon Nov 07, 2022 11:08 am
by smile
Hi sir
the 6508 can not send the diseqc CMD from the slave-demod. Because it 's diseqc pin has not connect to external devices.

Best Regards

Re: DiSEqC on Slave Tuners for Unicable setups

PostPosted: Mon Nov 07, 2022 3:11 pm
by LSD
smile Wrote:Hi sir
the 6508 can not send the diseqc CMD from the slave-demod. Because it 's diseqc pin has not connect to external devices.

Best Regards


yes, crazycat made this already clear, but there should be no blocking reason (we just have to make sure two diseqc messages aren't sent at the same time) for the slave to use the master to send the diseqc command.