issues with dvb-s(2) and diseq switches

Raymond Paulsen

I have issue with my tvheadend install, after upgrading my dell poweredge 2650 with 3 hauppage dvb-s2 cards to debian 7 with latest build i have seen weird behavior from the diseq, it seems that tvheadend has problems to controll them..

I use a t90 with 8 quad lnbs to 3-8x1 diseqs and then from each diseg to each dvb-s2 card.

The signal is great on all lnbs.

What i see is if i dont sett diseq repeat >1 (higer then or 1 ) and try to use the diseq tvheadend mixes muxes from the different diseq inputs. This means tvheadnd is not signaling a port switch change on the diseq properly. If i sett repeat to 1 or higer the first port in the diseq works fine, but iam not able to get signal on port2-8. I have tryed adding muxes manualy if the default list is outdated with no results.

To mee it seems that the new changes in that was done to the framework has broken the diseq stuff..

Its very rare someone is using a larger diseq then 3x1. When you use more then 3 inputs on the diseq you are forced to use diseq 2.0 2.1 sgnaling, and that is what i think is broke in tvheadend

If i revert tvheadend back to a very old release before the main update the diseq works perfect again

I hope anyone can help me with this issues

Regards
Raymond
Norway

Akos Sz

Hi,

I have similar observation on my system. (10/1 switch, 7 inputs, TBS-6922 board).

I found that setting diseqc repeats to
0 - Unreliable switching, the switch won't select the appropriate LNB input after channel switching
1 - Works fine, however I can see strange entries in the service list. Providers and services appears on different satellites at same frequency. This is definitely due to scanning or LNB switching fault.
2 - The scan happens on the right satellite but on wrong frequency. See my question here: https://tvheadend.org/d/1400-tuning-problem-wrong-transponder-is-received

Raymond Paulsen

Ok then its not my setup that is cousin this, i have tyed with different diseqs, tuner cards, server, operating systems build versions, everything i can think of, and the conclusion is the same, there is some funky stuff going on with diseg 2.0 2.1 protocol and switches larger then 3x1

if i switch to old framework problem is gone.

i hope its possible for the devs to have a look at this problem.

Raymond Paulsen

Darn,, its a configuration fault.

after studing how diseg 1.1 works and testing in tvheadend this is how it shuld be done with version 1.1/2.1

in the specs MAX 64 inputs can be used, uncommitted, committed setup. this is what cousing it

if only a single 8x1 lnb is directly attached diseg version 1.1 is used.

Use numbers 0-3 for LNBs behind first input on the uncommitted switch, then 4-7 and so on to support up to 64 ports using DiSEqC 1.1/2.1

so in tvheadend config for sattelit config you have to set it up like this

Diseq input port: port 0 ->> (0-3) Tvheadend config port = 0
Diseq input port: port 1 ->> (4-7) Tvheadend config port = 4

Diseq input port: port 2 ->> (8-11) Tvheadend config port = 8

This works like a sharm and keep diesg repeat to 1 in version 1.1 mode

Akos Sz

Hi, That is a really useful info. I did not know that port allocation.

7 months ago I posted a question regarding diseqc port mapping. See: https://tvheadend.org/d/990-weird-diseqc-switch-input-mapping I have not got any answer yet.

My diseq setup is still very odd, and even your input does not explain it.

I am using 7 inputs. According to your rule I would need to use the following TVH ports respectively.

2, 4, 5, 6, 7, 8, 9  My LNB inputs
8,16,20,24,28,32,36  proposed TVH port

Currently my working allocation is:

2, 4, 5, 6, 7, 8, 9 My LNB inputs
4,12, 1, 5, 9,13, 2  actual TVH port

My experience totally confutes your proposal. I do not understand how it is working. I could not find any rule between the LNB inputs and the TVH ports.
I made a quick test with this TVH settings but it does not work at all.

(I used my setup with a standard sat receiver before. The LNB config is correct.)

Raymond Paulsen

Here its ilustrated, its not my best drawing but i hope you understand the prinsiple

Akos Sz

Your explanation is crystal clear for me. Thanks.

I know what I did wrong yesterday. I started the LNB input numbering from 1 instead of 0. Hence they were shifted. I will try your recommendation once more today.

I still do not understand what is the difference among TVH ports 0,1,2,3. They should select the same input on the uncommitted switch if there is no committed switch on that port. In my case TVH port 1 selects LNB input 4 and TVH port 2 selects LNB input 8. Is it expected?

Raymond Paulsen

yes it starts on 0, :)

In theory you can select port 0,1,2,3 and it all should end up on port 0 on the 8x1 uncommited switch. if switches with feedback is used this can cause a problem, sins the card then wait for a aknowledge from the switch that it has changed to the actual port, if this acknowledge is not recived. it will RESEND DISEG REPEAT until it get this. if port 1,2,3 is selected i think its up to the commited switch to give this acknowledge but on 0 its the uncommited switch giving this acknowledge.

so just to keep clear of this problem select the FIRST port in the 4x1 sequence.. (0-3) = 0 | (4-7) = 4

Just to have it said there is different types of 8x1 10x1 switches, some are uncommitted types and some are committed, some have multiple internal diseq

4x1----|----2x1----|----INPUT---!

4x1----|

This will be the normal port list in tvheadend for a uncommited 8x1 switch

Diseq port 1.1/2.1 TVH config port
------------------------------------
Port0 = (0-3) = 0
Port1 = (4-7) = 4
Port2 = (8-11) = 8
Port3 = (12-15) = 12
Port4 = (16-19) = 16
Port5 = (20-23) = 20
Port6 = (24-27) = 24

Port7 = (28-31) = 28

Akos Sz

Hi,

I have tested and it works fine. Even with setting diseqc repeats to 0. Many thanks again!

I could not resist to decode my previous setup. I concluded that each sub port of every 4x1 sequence shifts the selected input by 4 until it reach the last input.

TVH port -> Diseqc input
0 > 0
1 > 4
2 > 8

3 > 8

4 > 1
5 > 5
6 > 9

7 > 9

8 > 2
9 > 6
10 > 6

11 > 6

12 > 3
13 > 7
14 > 7

15 > 7

So, I discovered this unknown behavior of my switch when tested which LNB appears at which TVH port settings.

Now the configuration looks much better.

Raymond Paulsen

yes this unknown behavior is because of this acknowledge from the switch.

Raymond Paulsen

Solved