[mythtv-users] How to limit 2xDVB-S (+DiSEqC) to 1 LNB at a time?

David Lister foceni at gmail.com
Fri Apr 24 22:08:24 UTC 2009


Hello, please HELP! :)

I guess this is quite a common setup, but I couldn't find anything
relevant in the docs nor on the mailing list. I have 2x TeVii S640
DVB-S2 cards (C1, C2). C1 input = cable, C2 input = C1 loop-out.
Cable connects to one port of a DiSEqC multiswitch (2 LNB's).

C1 -+-----[switch]----+- LNB1 (19.2E)
C2 -+                 +- LNB2 (23.5E)

MythTV DiSEqC config works, I have all channels, LNB switching rock
solid. If I had just one card (or two cards in two switch ports),
the configuration would be finished. Thing is, I need to tell MythTV
that there is ONE DiSEqC switch port shared among BOTH cards, i.e.
MythTV can access only one LNB (aka "Video Source"?) at a time.

Capture cards:
  [DVB : 0]
    DiSEqC: switch, 2 ports -> (LNB, LNB)
  [DVB : 1]
    DiSEqC: switch, 2 ports -> (LNB, LNB)
Video sources:
  S19 [EIT]
  S23 [EIT]
Input connections:
  [DVB : 0] -> Port 1 (LNB) -> S19
  [DVB : 0] -> Port 2 (LNB) -> S23
  [DVB : 1] -> Port 1 (LNB) -> S19
  [DVB : 1] -> Port 2 (LNB) -> S23

I thought having just 2 video sources should take care of my
setup, because with two independent cables I would probably
have 4, one for each accessible LNB. But it doesn't seem to work
this way. Unfortunately, I can't manage this exclusion manually;
I use custom rules searching all over the table and I'd have to
screen every recording for "undetectable" LNB conflicts...

1) How to make sure MythTV is using only one LNB on both cards
   at a time?

Second question is about input groups. With HVR-500 everything
worked out of the box, but I'm having difficulties with DVB-S.
Each card -> source connection has "Input Group 1" and "Input
Group 2" properties.

2) Could this be used for my shared DiSEqC switch port problem?
3) How to set both input groups for 2 tuners (per 4 multirec)?
4) Anybody has links with good info on input groups (apart from
   the documentation)?


Thank you in advance!!

-- 
David Lister


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