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scan-s2 / szap-s2 and DiSEqC switching

scan-s2 / szap-s2 and DiSEqC switching

Postby nicks272 » Thu May 17, 2012 12:29 am

Hi,

I'm testing with scan-s2 and szap-s2 as described in the README_TBS6981, but I'm getting problems which I think are something to do with DiSEqC switching.

Firstly, it seems that the scan-s2 default output format (VDR) doesn't include the DiSEqC switch position (and szap-s2 has no option to specify switch position), so that subsequent attempts with szap-s2 always look on "sat 0" which fails with the other satellites. But if I add the "-o zap" option to the scan-s2 commands (and pass the shorter channel names to szap-s2), it looks on the correct switch position and I am able to get a lock from all four satellites.

However, the switching still seems to be intermittent... sometimes a zap will work and sometimes it won't. In particular switch positions 0 and 1 seem to get a lock every time, but switch positions 2 and 3 often fail. Sometimes I can get a lock when I CTRL-C and retry, sometimes I try a scan or I zap to another switch position first and then I can get a lock but not necessarily on the first attempt.

When the same cable is connected to an alternative set-top box (a Technomate TM-5000, I can't easily see the DiSEqC switch but I think it's a Technomate TM-4S) channels on all 4 satellites are received with no problems. For sure something isn't working between the TBS6981 and the DiSEqC switch but I don't know what.

I'd really appreciate some advice on diagnostics I can do to identify the problem and hopefully the solution.

Many thanks,

Nick
nicks272
 
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Re: scan-s2 / szap-s2 and DiSEqC switching

Postby SergioDanielG » Thu May 17, 2012 4:15 am

Hi nicks272.
When you scan channels with scan-s2 to use with szap-s2, need to use "-o zap" and "-s N" where N is port number from 0 to 3, or "-S N" where N is port number from 0 to 15, to indicate witch diseqc port use to scan.

To test szap-s2 make a file manually. Include one channel per satellite, something like this:
Code: Select All Code
Ch1:10123:H:0:1:2:0:0
Ch2:10234:V:1:3:4:0:0
Ch3:10345:H:2:5:6:0:0
Ch4:10456:V:3:7:7:0:0

but use real and knocked parameters and similar transponder, for example all DVB-S, FEC 3/4, QPSK. Then try tu zap including "-i" parameter to run interactive

szap-s2 -p -H -r -a 0 -c zapfile.conf -i
> Ch1

-a 0 or -a 1 for first or second tuner. Here wait to tune and in other terminal run "mplayer /dev/dvb/adapter0/frontend0". If it's all ok, pass to next channel.

> Ch2

and next
> Ch3
and next
> Ch4

Try this and say me if it work or no.

Best regards.
SergioDanielG
 
Posts: 356
Joined: Tue May 31, 2011 3:53 am
Location: Tostado (SF) Argentina

Re: scan-s2 / szap-s2 and DiSEqC switching

Postby nicks272 » Thu May 17, 2012 8:48 am

Thanks, I found channels on 3 satellites all DVB-S, FEC 5/6, QPSK and tried that:

Code: Select All Code
$ ./szap-s2 -p -H -r -a 0 -c ~/zapfile.conf -i
reading channels from file '/home/nick/zapfile.conf'
>>> TELE5
zapping to 1 'TELE5':
delivery DVB-S, modulation QPSK
sat 1, frequency 10796 MHz V, symbolrate 27500000, coderate auto, rolloff 0.35
vpid 0x00a4, apid 0x0060, sid 0x3d59
using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
status 1f | signal  74% | snr 100% | ber 0 | unc 0 | FE_HAS_LOCK

>>> Sky News Intl
zapping to 2 'Sky News Intl':
delivery DVB-S, modulation QPSK
sat 3, frequency 12603 MHz H, symbolrate 22000000, coderate auto, rolloff 0.35
vpid 0x050a, apid 0x08f2, sid 0x1c7a
openening pat demux failed: No such file or directory
status 1f | signal  49% | snr  93% | ber 0 | unc 0 | FE_HAS_LOCK

>>> Channel 5
zapping to 3 'Channel 5':
delivery DVB-S, modulation QPSK
sat 2, frequency 10964 MHz H, symbolrate 22000000, coderate auto, rolloff 0.35
vpid 0x092a, apid 0x092b, sid 0x1e15
openening pat demux failed: No such file or directory
status 1f | signal  74% | snr 100% | ber 0 | unc 0 | FE_HAS_LOCK


Sometimes it would fail to get a lock (with snr 0%) and I needed to re-enter the same channel (or try a different channel) before getting a lock.
The message "openening pat demux failed: No such file or directory" always appeared from the 2nd zap onwards, regardless which channel I chose for the 1st zap. Also I had to invoke
Code: Select All Code
mplayer /dev/dvb/adapter0/dvr0
to see the picture.
nicks272
 
Posts: 8
Joined: Tue May 15, 2012 11:47 pm

Re: scan-s2 / szap-s2 and DiSEqC switching

Postby SergioDanielG » Thu May 17, 2012 9:35 am

Well, all like ok, except this "openening pat demux failed: No such file or directory". Please, when you see this message, run inmediatelly "ls -l /dev/dvb/adapter0/" and "dmesg". Copy and post the output.

Other things: in same cases it's necesary add same parameters when you run szap-s2, fec, rolloff, coderate and as this are option to szap-s2, when you try tu tune other TP, szap-s2 can't do it.
And a question..
Do you want to use your card only to watch TV? If yes, maybe you must try VDR.

Best regards.
SergioDanielG
 
Posts: 356
Joined: Tue May 31, 2011 3:53 am
Location: Tostado (SF) Argentina

Re: scan-s2 / szap-s2 and DiSEqC switching

Postby nicks272 » Fri May 18, 2012 12:09 am

So here is just after the "openening pat demux failed" error:
Code: Select All Code
$ ls -l /dev/dvb/adapter0
total 0
crw-rw----+ 1 root video 212, 1 May 17 15:51 demux0
crw-rw----+ 1 root video 212, 2 May 17 15:51 dvr0
crw-rw----+ 1 root video 212, 0 May 17 15:51 frontend0
crw-rw----+ 1 root video 212, 3 May 17 15:51 net0

No messages added to dmesg when this happens, but here are the relevant parts during system startup:
Code: Select All Code
$ dmesg | grep -i -e "cx23885" -e "tbs"
[   11.775225] cx23885 driver version 0.0.3 loaded
[   11.775259] cx23885 0000:02:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
[   11.775659] CORE cx23885[0]: subsystem: 6981:8888, board: TurboSight TBS 6981 [card=33,autodetected]
[   12.501155] cx25840 2-0044: cx23885 A/V decoder found @ 0x88 (cx23885[0])
[   13.244897] cx25840 2-0044: loaded v4l-cx23885-avcore-01.fw firmware (16382 bytes)
[   13.252554] cx23885_dvb_register() allocating 1 frontend(s)
[   13.252558] cx23885[0]: cx23885 based dvb card
[   13.253883] TurboSight TBS 6981 Frontend 0 Attaching...
[   13.345252] DVB: registering new adapter (cx23885[0])
[   13.345256] DVB: registering adapter 0 frontend 0 (TurboSight TBS 6981 DVBS/S2 frontend)...
[   13.372891] TurboSight TBS698x Dual DVB-S2 card port0 MAC=00:22:ab:f0:4e:40
[   13.372893] cx23885_dvb_register() allocating 1 frontend(s)
[   13.372899] cx23885[0]: cx23885 based dvb card
[   13.372902] TurboSight TBS 6981 Frontend 1 Attaching...
[   13.456134] DVB: registering new adapter (cx23885[0])
[   13.456143] DVB: registering adapter 1 frontend 0 (TurboSight TBS 6981 DVBS/S2 frontend)...
[   13.483841] TurboSight TBS698x Dual DVB-S2 card port1 MAC=00:22:ab:f0:4e:41
[   13.483846] cx23885_dev_checkrevision() Hardware revision = 0xa5
[   13.483851] cx23885[0]/0: found at 0000:02:00.0, rev: 4, irq: 17, latency: 0, mmio: 0xfe800000
[   13.483858] cx23885 0000:02:00.0: setting latency timer to 64
[   13.508111] Registered IR keymap rc-tbs-nec
[   13.508293] input: cx23885 IR (TurboSight TBS 6981) as /devices/pci0000:00/0000:00:05.0/0000:02:00.0/rc/rc0/input10
[   13.511895] rc0: cx23885 IR (TurboSight TBS 6981) as /devices/pci0000:00/0000:00:05.0/0000:02:00.0/rc/rc0
[   13.511976] input: MCE IR Keyboard/Mouse (cx23885) as /devices/virtual/input/input11
[   13.512121] rc rc0: lirc_dev: driver ir-lirc-codec (cx23885) registered at minor = 0
[   37.322967] TurboSight TBS 6981 Frontend:
[   37.322969]  tbs6981fe - software version is 1.95.2.5
[   37.322971] TurboSight TBS 6981 Frontend:
[   37.322971]  tbs6981fe - Successfully Initialized

I follow with more info in my next post...
nicks272
 
Posts: 8
Joined: Tue May 15, 2012 11:47 pm

Re: scan-s2 / szap-s2 and DiSEqC switching

Postby nicks272 » Fri May 18, 2012 12:13 am

I also include the output of szap-s2 for 3 attempts where the 2nd attempt fails to get a lock:
Code: Select All Code
>>> Sky News Intl
zapping to 2 'Sky News Intl':
delivery DVB-S, modulation QPSK
sat 3, frequency 12603 MHz H, symbolrate 22000000, coderate auto, rolloff 0.35
vpid 0x050a, apid 0x08f2, sid 0x1c7a
openening pat demux failed: No such file or directory
status 1f | signal  49% | snr  94% | ber 0 | unc 0 | FE_HAS_LOCK

>>> Sky News Intl
zapping to 2 'Sky News Intl':
delivery DVB-S, modulation QPSK
sat 3, frequency 12603 MHz H, symbolrate 22000000, coderate auto, rolloff 0.35
vpid 0x050a, apid 0x08f2, sid 0x1c7a
openening pat demux failed: No such file or directory
status 00 | signal  74% | snr   0% | ber 0 | unc 0 |
status 03 | signal  74% | snr   0% | ber 0 | unc 0 |
status 01 | signal  74% | snr   0% | ber 0 | unc 0 |
status 01 | signal  74% | snr   0% | ber 0 | unc 0 |
status 01 | signal  74% | snr   0% | ber 0 | unc 0 |
status 03 | signal  74% | snr   0% | ber 0 | unc 0 |
status 01 | signal  74% | snr   0% | ber 0 | unc 0 |
status 01 | signal  74% | snr   0% | ber 0 | unc 0 |
status 03 | signal  74% | snr   0% | ber 0 | unc 0 |
status 01 | signal  74% | snr   0% | ber 0 | unc 0 |

>>> Sky News Intl
zapping to 2 'Sky News Intl':
delivery DVB-S, modulation QPSK
sat 3, frequency 12603 MHz H, symbolrate 22000000, coderate auto, rolloff 0.35
vpid 0x050a, apid 0x08f2, sid 0x1c7a
openening pat demux failed: No such file or directory
status 00 | signal  49% | snr  93% | ber 0 | unc 0 |
status 1f | signal  49% | snr  94% | ber 0 | unc 0 | FE_HAS_LOCK

I can also mention that I wondered if the TBS6981 card wasn't getting enough power from the PCIe slot to reliably send the commands to the DiSEqC switch, so I added the 6981's power adapter with a single molex connection, but this seemed not to make any difference at all.

Actually I'm setting up this machine as a MythTV backend, where I had limited success scanning (but it did pick up some channels) but it always fails to get a lock on any channels at DiSEqC switch positions 2 and 3 (Astra28.2°E & Astra19.2°E), but has no problems with positions 0 and 1 (Hellas39.0°E & Hotbird13.0°E). But for now I ignore MythTV and just try to verify with scan-s2 and szap-s2.
nicks272
 
Posts: 8
Joined: Tue May 15, 2012 11:47 pm

Re: scan-s2 / szap-s2 and DiSEqC switching

Postby nicks272 » Sat May 19, 2012 10:42 pm

Just an update... I tried switching the satellite cable to the card's other input and repeated the scan-s2 / szap-s2 tests with /dev/dvb/adapter1 (instead of /dev/dvb/adapter0 I used before) and the behaviour is the same - intermittent switching/locking.
I am not an expert, I can only guess that maybe the card/driver isn't sending the right commands to the switch (since the switch still works perfectly with the set-top box), either a hardware issue or just a configuration issue. Is it possible to see in a log somewhere what commands are being sent to the switch to verify they are correct?
Thanks.
nicks272
 
Posts: 8
Joined: Tue May 15, 2012 11:47 pm

Re: scan-s2 / szap-s2 and DiSEqC switching

Postby nicks272 » Mon May 28, 2012 7:38 pm

OK, so I gained access to the DiSEqC switch and swapped the cables on inputs 1 and 3. Getting a signal lock with szap-s2 remains ok on inputs 1 and 2 and remains intermittent on inputs 3 and 4. I can't find any technical information on the switch, but presumably it's doing the switching with 13V/18V and 0kHz/22kHz, and one of these (which distinguishes inputs 1+2 from inputs 3+4) is failing to reliably reach the switch from the card.

I have now connected all 3 molex power supply connectors to the card's power supply adapter with no change to the behaviour. I now think that the correct commands are being sent (otherwise it wouldn't manage to sometimes get a lock) but those commands are not being sent reliably. I estimate that the cable length from the switch to the card is 15m (is this considered a short or long distance?). If I can find a way to do a test from a closer distance I will do so and report the result.

It would seem that may this is a general issue with PC satellite tuner cards in general, unlike mains-powered set-top boxes that send stronger commands to the switch, is that correct? I still can't be confident that this behaviour should be expected with the setup I've described, or if it's because of an underlying hardware/configuration problem with the card. Some opinions of more experienced/knowledgeable people would be very helpful.

Hopefully this is useful information for anyone else struggling to get their setup working.
nicks272
 
Posts: 8
Joined: Tue May 15, 2012 11:47 pm

Re: scan-s2 / szap-s2 and DiSEqC switching

Postby steven » Thu Jun 07, 2012 9:47 am

Hi nicks272

Thank you very much for sharing your solution. :D

Kind Regards

steven
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Re: scan-s2 / szap-s2 and DiSEqC switching

Postby miyop » Tue Dec 18, 2012 5:44 pm

Can anyone tell me how to open this card with vlc? I installed the driver and vlc. But now I don't know how to open it. I'm not an experienced linux user.
miyop
 
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