DiCSeq peculiarity with Linkbox and ASC1

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Active SatelliteGuys Member
Original poster
Sep 20, 2017
Got a Linkbox 9000i Local tied to an ASC1. Works great up to satellite position 13. On Sat 14, ASC recalls position fine, but changing channel or selecting the sat from the LB channel menu fails. Says, "moving dish", ASC wakes up display, but doesn't change position.

But under the Sat Install menu item, I can select the sat in pos 14, and ASC takes me there.

Thinking is the Linkbox who had the issue. Recommendations on what to poke at next?
Is it just 14? What about 15? Could be a bug in the LB software, where that memory position interacts a weird way. Not heard of it before though.
Is it just 14? What about 15?

Yeah, tried different memory spots to no avail. Number of other things, too, like completely deleting the sat from the list and starting from scratch. Same result.

I confirmed my other EX box has no trouble with sat mems above 13. So will wipe the LB and start again.

Film at 11.
Update: LinkBox 9000i Local got a factory reset. I deleted all the sats in the factory list and started clean. Then, I manually entered into the 9000i the sat names, positions, and memory number as it is stored in the ASC1. I set the 9000 to do a multi-sat blind scan, also known as the 3-hour-tour of the visible geo arc. This gave me time to finally "start" trenching my cables going out to the antenna (keyword: start. hihi!).

The scan worked fine.

The original issue is present, but changed. It has nothing to do with DiCSeq memory 14.

On a hard reboot, if one steps through channels, one at a time, DOWN the list in All Satellites, the DiCSeq command to the ASC1 seems to work. This suggests at least the first channel listed for a satellite X sends DiCSeq position information correctly -- at least after a reboot. Doing so UP the list doesn't send position command.

Picking random channels in the All Sateliites list sometimes works, sometimes doesn't. Channels at the bottom of the list never work. Sometimes, channels as far down as 5 in the list work, some don't. I've not had a channel below 5 deep in the list work. Favorites lists are problematic in this respect.

Walking "sideways" in the channel list between C-band birds on the 9000i, the channel it wants to select seem to stick in terms of position in the list -- that is to say, start on bird X, ch 10 of 20 ... move side arrow key to bird Y, the channel selected is proportionally deep in that bird's list (if bird Y has only 4 channels, it sticks on ch 2). But if one stays on ch1, a sideways walk works (for a while).

And yet... on some channels, it doesn't seem to send a position change command at all (ASC1's display never lights up).

Doing enough random channel selections precludes the downward walk/sideways ch1 walk from working, until one reboots the 9000i.

Next troubleshooting steps:

- Delete all channels to 5 deep (or fewer), walk around.
- Try using the factory preset bird definitions with manually added DiCSeq memories.
- Upgrade the fw (I'm running one version behind latest).

It's an interesting problem.

I have a junky "V7" box I bought before I knew "what it was", it works wonderfully with the ASC1.

I need to look at the DiCSeq protocol some more, and see if there's a way I can sniff the commands riding the coax, comparing the two RXs.
You can see them on a DSO. Be interesting to see the difference in the same command between receivers.
Use this thread and see the schematic I came up with. You only need part of it of course and an O-Scope.
Arduino DiSEqC Decoder
And yet... on some channels, it doesn't seem to send a position change command at all (ASC1's display never lights up).

Is it not sent, or is it not received? Hard to say.

I would have some questions, here.
What cabling is there between receiver and ASC1 and LNB?
Does your box have diseqc repeat-options?
Is there different firmware for your box, that you could try?
Has it once functioned properly, or is this a new setup?

Thanks all ...

Titanium - Thanks for the offer in the string reader. I'll let you know if it looks like that box will answer some burning questions. And, the ASC1 is a stellar box!

@EST - awesome Arduino project! That one is on my build list now. Will certainly inspect with a DSO just to get a sense of what terms/commands might be different leaving the STBs.

a33, new setup, RX/TX question is the right thing to ask here. Cable stack is as follows:

STB -> DiCSEq switch, Pansat 4 port -> ASC1 on port 2 -> Norsat 3220 LNB.

Switch is configed in the 9000 as DiCSEq 1.0.

When STB is the junky V7, this scheme works. The LinkBox 9000 coughs.

Port 1,2,3, or 4 on the switch, same result.

New info:. Latest 9000 fw made no difference. I did try eliminating the DiCSEq switch, and confirmed the ASC1 is happy with the LB9000. I then tried re-installing the switch, configuring as a DiCSEq 1.1, with Cascade. That yielded no different result.

Will try to get the scope out and sniff the strings this weekend.
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So if I understand right:
With one box it works flawlessly.
With the other box it doesn't work. But if you leave the 4/1 switch out, it works again.

So the diseqc 1.2 signal from the 'other' box doesn't reach the ASC1, when the switch is inbetween.
I don't have the equipment that you have, but I would try the following:
Can you set diseqc repeat in the 'other' box? Or can you set order of diseqc commands (first 1.0; then 1.2)? Does it work then?

Or, as a hardware setup solution: Does it work in this cable-stack order: Receiver -> ASC1 -> diseqc switch ->LNBs?

That is what I would try. No garanties, of course...

Try putting the ASC1 before the DISEqC switch, not after it. Thats how I have mine setup, receiver, ASC1, 8 port DISEqC switch, 7 dishes. Mine works great this way.
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This sounds like a STB or distribution issue. When checking for control signal strings, verify if the problem is associated with the polarity voltage. Does it work properly changing to a horizontal channel/transponder? Does it work properly changing to a vertical channel/transponder?

Test open and under load at both the STB LNB port and also at the end of the coax jumper.

Test the 22KHz/DiSEqC amplitude on a Horizontal and a Vertical transponder. The level is spec'd 650 mV (±250 mV). Also test the LNB polarity voltage to be 13/18Vdc (+/-10%).
I missed the distribution flow and comments by a33 and .Raine , which were made the same time I was posting earlier today.

The DiSEqC switch should be installed after the ASC1 when the STB is issuing a single DiSEqC string call-out. The ASC1 loop-out passes all control commands (22KHz/DiSEqC) without needing the DiSEqC repeat option. This is typical for DiSEqC motors and controllers.

As a33 pointed out, with the switch inline before the controller, the 2nd DiSEqC string command will not pass through to a cascaded device unless the STB is in the DiSEqC repeat mode. If the STB supports DiSEqC repeat mode, the switch port will be opened for command pass-through to a cascaded device. Maybe the other STB sends DiSEqC repeat mode by default?
I initially have a lot of issues with my linkbox 9000I local and the pansat 4 port DISEqC switches. I got a different brand and it works fine. Had the issue on both my c-band with ASC-1 (in all configurations) and my 4 ku dish array at the house which is where the 9000I local lives. Ironically the Linkbox will not operate my generic KU motor I got from sadoun either with any version of firmware. However I did test it with a stab motor and it works fine. I have been told the linkbox is kinda picky with DISEqC.
Right now, ASC1 is first in the line from STB and all is well. I started recording some 22kHz commands from the 9000, but haven't done the same with the "other" box for comparison. Will post results of that when I have them.

Yes appears 9000 is "picky" with DiSEqC.
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