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Toshiba 20vl66 LCD IR control

DarksideDarkside Posts: 345
in AMX General Discussion
Hi all,

Hoping someone may have played around with this 20" lcd screen...

The hand control only has a toggle control for power, and it appears that no other button will turn it on (sometimes a channel button might bring a device on).

We have a sys with a shipload of these screens in it and sometimes the screen does not turn on - either because it missed it, or the data got bumped into on the way etc. It is random across the 40 screens and random as to when it might do it.

I wondered if anyone would know if any other Tosh device will operate this screen, and if so, does that remote have discrete on off. (Wondering if say a tosh cube remote might fire the lcd)

It's a long shot, but with the wealth of knowledge and help here, I hope I might find a solution!

Any help gratefully received

Comments

  • NMarkRobertsNMarkRoberts Posts: 455
    Stephen Bolton wrote:
    Hi all,We have a sys with a shipload of these screens in it and sometimes the screen does not turn on - either because it missed it, or the data got bumped into on the way etc. It is random across the 40 screens and random as to when it might do it.

    I suggest that you should doubt that the behaviour is random, and go find what factor makes a difference. In my (humble) experience the most likely reason for random behaviour of an IR controlled device is that the pulse length is too short - or possibly too long.

    I am also puzzled about "the data got bumped into on the way" and would appreciate some details on that.
  • toddttoddt Posts: 28
    If you can't find a discreat power on/off ir channel, you most likely will have to use a power current sensor. Which with 40 displays will be a costly addition.
  • DHawthorneDHawthorne Posts: 4,584
    I'm finding more and more frequently that power current sensors are not viable solutions. The power draw between "standby" and "on" is so minute that any kind of current fluctuation (even caused by the device itself when it is powering up) will cause a false reading, and painstaking adjustments might work one day and not the next. I understand this is not a very helpful post - more of a warning only to use a current sensor as a last recourse and to make double sure it can make a solid determination of the power state if you do. I spent hours fighting with one on a Dell monitor (never my choice, but the customer already owned it), until I finally dug up some discretes for it.
  • DarksideDarkside Posts: 345
    NMarkRoberts wrote:
    I suggest that you should doubt that the behaviour is random, and go find what factor makes a difference. In my (humble) experience the most likely reason for random behaviour of an IR controlled device is that the pulse length is too short - or possibly too long.

    I strongly suspect the run lengths are an issue here - not the code - and that it may well be a sagging power supply issue coupled with, perhaps, some deforming of the burst shapes over these distances. This is why I would like to get a discrete ON so that the cmd can be issued again as a safety. I have already tested for min pulse time and it appears to not like a pulse time of 3 very much (over these distances), so have left it at 5. I haven't considered that 5 is too short.

    The handler for the screens is very tightly controlled and what cmd any screen gets and when it gets it is extremely strict. There have been reports of totally random screens simply not doing as they are told. Sometimes it is days before it occurs. At this early stage it would appear that we haven't even had the same ones misbehaving twice.
    NMarkRoberts wrote:
    I am also puzzled about "the data got bumped into on the way" and would appreciate some details on that.

    Spikes, large RF emissions from plant rooms etc. Kitchen devices kicking in etc can all 'bump into transmissions' causing corruption of serial/ir data if large enough. Perhaps I should have just said splatter the data!

    Cables shouldn't be close to these sorts of animals in a perfect world - of course - but, .....were not in a perfect world!

    The cable type used for the ir tx will allow us to implement the screen to help reduce this risk. We'll probably do this as a matter of course in this case.

    As for the current sensors, yes it would be a huge cost, and, IMHO they are not well suited to this type of device.

    Thanks for the input!
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