DM500HD do not comply with diseqc spec

    Hello!



    I among many others have discovered the poor funcionality with DM500HD and Diseqc equipment. Some have switches and rotors that work, others don't. This is caused by bad timings and/or burst amplitude within the 22kHz signal from the STB.



    I have 2 questions:



    1. Are DMM aware of these problems and maybe working on a fix/solution?


    2. In earlier images (drivers) you could alter the burst voltage with "echo n > /proc/stb/frontend/0/tone_amplitude". This trick does not longer work since the parameter tone_amplitude no longer exist. Are there a "new" way to do the same thing?



    Best Regards,


    M

    Hello M


    I think I have similar issues with my new DM 500 HD - see my post : DM500HD and Diseqc 1.2


    My Metronics steerable dish worked fine with my DM 7000, but is very erratic with the DM 500 HD.


    The DM 500 HD works fine with a single satellites, and seems OK when I use the a subset of the 3 with default service lists (28.2E, 19.2E, 13.0E). But when I try to re-scan one of these, or add another (typically 5.0W), it seems to loose position, so that subsequent moves can point the dish anywhere. I cannot even make the positioner setup goto /store page work reliably.


    Can you point em to any threads which might a clue as to how to improve this.


    Thanks


    John

    John Robinson, York, England.

    Hello John.


    Yes your problems is probably related to the same "bug". I hope someone who have more knowledge than me on enigma2 can help me (us) out on this (question 2 above) for some testing with the burst amplitude.


    I really hope that someone at DMM reads this also and at least investigate it further. It's a pity that such a great box have this flaw... I hope they really are aware of this "bug".




    If i can get me some extra time somewhere (have wife-material and kid and to much to do...) I will hook up a scope to analyze it more exactly, but I don't know when that will be. Maybe we have some answers here before that.




    However I can tell you that I have a lot of sat equipment (receivers incl several E1 boxes, diseqc switches, LNB:s etc.). This (DM500HD) is the first stb that cannot operate ANY of the switches correctly. I have tried all possible configs with switches/LNB:s with the same bad result. It is not a bad individual unit either, several different DM500HD units shows the same...


    When Googling about this it seems that this is a relatively common problem also on DM800 and DM7025 so my best guess is that this is a common Enigma2 problem and therefore a software/driver bug. Some people also claims that their boxes have started working after tuner replacement, and maybe they have, but I see it like this: If some voltage or timings are "on the edge" of the correct value (set somewhere in the software), a new tuner with a capacitor value sligthly diffrent can make a BIG difference and indeed cause the switches to work again.




    For you John I don't have any suggestions (for now at least) but hopefully some DMM related guy (or other) reads this and gives us advice.


    If I get any bright ideas or help elsewhere I will come back here and post it.




    Please DMM, help us :smiling_face:




    Best Regards,


    M

    Nice to hear that you have got your system working. However, we have different issues so the questions above remains. I hope someone can help us (other) in the right direction.


    /M

    will this help if you are still having problems
    i have never use the usuals settings long/lat
    for diseqc motors having always used the 36v motor
    and now receivers dont have this feature i have a v-box
    try this for the motor set up on usuals
    menu.setup.ok service search>ok tuner configuration>ok
    choose tuner>ok then on the reception settings panel
    set the configuration mode to simple
    next line down> mode set to possitioner
    then enter your long/lat settings
    now the motor setting is set for usuals
    then exit and go to manual scan >ok
    on the service scan set type of scan for multisat
    then enable the sats you wish to scan from the list
    and after this click>ok and the scan of sats and chns will start
    as i said i alway start from my west satellite and scan west to east

    Just to clarify: the problem is not how to configure and setup a motor, the problem is a bug in software, or maybe, a design flaw in the hardware. How to setup switches or motors is not what I am asking here, I know how to do that.


    What I do mean is that it is a fault (software or hardware) that causes diseqc switches (and motors) to function poorly or not at all and it is that I (and others) hope to get some help with to solve. Most of us users do not have motors but need working diseqc for the swithes. I don't think it is a good solving to the problem to search and buy just a particular brand and a particular type of switch just to, maybe, get it to work. If it says diseqc compliant it should be diseqc compliant... and it's not for the moment!


    I will analyze the 22kHz signal timings and voltages more closely in the near future, but I have very little spare time so I don't know when that will be.


    In the meantime I would be really glad if some DMM representative would say what they think about this.


    The DM500HD is a wonderful receiver, but it is a shame that it (for the moment at least) have this design flaw or software bug...

    OK, for those of you that are interested in this problem (DMM apperantly is not) I have some new info.
    This evening I have made some measurements of the voltages and signals from the stb and compared it to my older enigma1 stb:s (e.g. DM600PVR) and some stb:s of other brands. The DM500HD (and probably other e2:s also) does NOT deliver the correct signals/voltages to operate diseqc correctly. There are several errors appearing on the signal which feeds the switches (and other stuff like motors), some bursts that shouldn't be there and some strange diseqc messages that are very questionable...
    However, the main problem why the switches doesn't work is because the voltage drop that shall occur just before (typical 15 ms) the diseqc message DO NOT OCCUR at all. Enigma1 stb:s do switch OK and so do my other tested non-linux stb:s. They all have the correct voltage-drop-gap.
    To verify my findings I made a simple test: It seems that the DM500HD keeps sending the diseqc message as long as it doesn't have tuner lock, and it won't get tuner lock due to the faulty signalling to the switch. Now, while it keeps sending the messages, I just pull out the coax from the stb and put it back again... Voila! The switch switches like a charm. And so do all the other 4 switches I have bought in my desperation.


    Now, I do not know where the fault is, software or hardware, but I do know that the DM500HD is not compliant with diseqc specification and that MANY people have struggled to get the box to work as expected.


    White papers for Diseqc are readable at Eutelsat site.


    I just want to let you know about this. I haven't heard a word from any DMM rep yet other than the ticket was closed in a hurry, no words.


    Regards,
    M

    Well I did mean voltage-drop, but now after some thinking I would like to take that back... as you said it doesn't make sense or is required. However, my simulated "voltage-drop" causes the switches to switch... But due to the design of a switch a "diseqc-reset" can be done in several ways including a rapid voltage-drop and it is probably thats what happens. In that case there is another possibility, namely that the normal diseqc-reset command is not transmitted correctly from the stb.


    I will go on with my analyze of the signals, but it would be really helpful if someone else also would particpate in this (and most of all DMM themselves) because the signalling is NOT correct. As I see it it is the only thing that is bad with this, in all other ways, great receiver. All, and especially DMM, should be interested in fixing this.


    I would like to mention another strange thing I saw when looking at the scope: when turning OFF all diseqc commands (toneburst, committed, uncommitted all off) there was, as expected, no commands at all leaving the receiver. But when turning toneburst ONLY on, the stb sends toneburst (12ms) as expected but ALSO full diseqc (40ms) commands, which shouldn't be there...


    It is more than welcome if someone would like to help me find out what is wrong.


    The fact remains, older Enigma1 machines operates diseqc perfect. Enigma2 (at least DM500HD) does not.

    yes, i can confirm - E2 dreamboxes friendship with different diseq switches is something ....
    and different models have different simpthoms and solutions


    sometime helps:
    change tone amplitude;
    set repeat of diseq commands;
    increase voltage;
    send some fake committed comad before send your uncommitted comand;
    add parameter `config.Nims.0.diseqc13V=true` into /etc/enigma2/settings, but with that parameter last year 8k-s cant get signal at all;


    sometime nothing(had to change LNBs and switch):
    http://www.dream-multimedia-tv…age=Thread&threadID=13599


    p.s.
    also dmm tuner drivers are buggy, on 8k-s you can set any parameter in Inversion and get a signal

    For the past years (can't remember how many!) I have run a venerable DM7000 with Enigma 1 and a HiSat HH100 positioner. Over Christmas the DM7000 died.


    I now have a DM500HD which works fine with a static dish, but seems completely unable to drive the positioner. I have tried the various suggestions made in this and other threads with no success: no movement of the positioner at all.


    I'm wondering if anyone else has had this experience? I'm uncertain at the moment whether the Dreambox is broken or whether this behaviour is just a symptom of the DiSeq incompatability issues noted by others.


    Any views or advice much appreciated.

    Last November I upgraded my DM7000-S to a DM500HD. The picture quality is excellent.


    But I had a problem with setting up and maintaining satellite positions with Diseqc 1.2 (not USALS) steerable dish. This had been working for years with the DM7000-S.


    After software upgrades and a replacement tuner had failed to improve the situation, I decided to follow up a suggestion (this thread) that the Diseqc commands on this newer Dreambox (and maybe other Enigma2 boxes) were not correctly formatted.


    I borrowed a 'scope from work, and found I could tap of the co-ax inner into a passive circuit which which keeps the 22Khz tone and also rectifies it to show the pulse widths. I planned to detect and decode the protocol from the bit level upwards.


    I fed the signals into a PC audio input box (Behringer UFO202), and cranked up Audacity to sample stereo at 100Khz. Then I could see, and record, the 22Khz signals, and the variable width pulses.


    With this logging in place, I started to set up and the satellite positions, and exercise the dish movements. I would be able to go back over the recording immediately before an error, and check the command formats.


    And I kept adding satellites, moving the dish - and it never went wrong. I have had this setup in place for 10 days now, with twice daily recordings from each of 5 satellites between 5.0W and 28.2E, and it has not put a foot wrong.


    So, as far I am concerned, the problem is fixed. If I had not spent enough time on this already, I would experiment to find out what is the minimum circuit I need to keep the system running, but I am just pleased to have it going.


    So if anyone encounters similar issues, just try loading the signal a bit - probably a 100nF capacitor and 1.2K resistor would have done the trick.


    If anyone wants, I can post the full circuit and some logged data.


    Best wishes


    John

    John Robinson, York, England.

    HI guys,


    I'm a new user of a DM500 HD, and like most of you I'm facing an issue with the DiseqC. Doesn anyone find out the real problem? Is there any fix or setting or also a new device to make the DiseqC working well (I'm not using a motor, but 3 LNBs).


    Your help is appreciated.


    best regards
    Filipe