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Samsung PPM42M5H - Ignores ON command

bmitchellbmitchell Junior MemberPosts: 41
Has anyone else had to control a Samsung PPM42M5H unit?

I am finding that it ignores the RS232 ON command and that the ON command needs to be sent several times.

Once it is on, the source selection and power OFF work perfectly.

It is only the power on.

I have tried the chard command at various delays, but it does not seem to make a difference.


  • DHawthorneDHawthorne Old Timer Posts: 4,584
    I don't have any experience with the Samsungs, but other makes (in particular, the Sharp LCDs) kill the RS-232 port when the power is off. The Sharps at least let you override this byt turning off the power savings feature; it's something you might want to look into. If that fails ... well, it's inelegant, but you could stick an emitter on it just for the power on command, and use the RS-232 for the rest and for feedback. I did that once with a Sharp until before someone discovered the power savings thing and posted it here.
  • Thomas HayesThomas Hayes Junior Member Posts: 1,164
    Hi Brian
    I had a problem like this with the NEC GT-5000, turns out I had to set the unit to a stand-by mode rather than ON/Off. Took awhile to figure it out because sometimes if I burst the "ON" command it would work.
  • bmitchellbmitchell Junior Member Posts: 41
    I was thinking along the lines of the Sharp power save mode, but cannot find anything related to this concerning the Samsung. It does seem like it is "sleeping" though.

    Hey Thomas, the only command I can find for this unit is power (there is no standby etc).

    I have controlled Samsung plasmas in the past, but this is the first one I have come across where the baud rate is 9600 instead of 19200.

    The last Samsung I controlled was the PPM50H3 and it has the same protocol except the baud rate is 19200. It worked okay.

    Of course to add fun to this, I am doing the work remotely.
  • FrankieFrankie Junior Member Posts: 71
    I have had a couple of Sharp projector do that to me. Turned out to be something wrong with the projector. We sent the unit in for repair and they replaced the rs-232 part of the projector. Just FYI
  • Joe HebertJoe Hebert Junior Member Posts: 2,159
    Similar with Fujitsu

    Can?t comment on Samsung but I had a similar experience with a Fujitsu that has a protocol in the format of:

    Me --> Hello
    Fuj --> OK
    Me --> Do this
    Fuj --> OK
    Me --> Goodbye

    When the Fujitsu was powered off it didn?t always respond with an OK after a Hello was issued. The routine had to ask Hello several times (in x second intervals) before it eventually got back an OK and then once the OK came it could issue the Do this. After the unit was powered on it always responded to a Hello the first time. Also in between the time of Hello and Goodbye, the front panel and IR is disabled.
  • Thomas HayesThomas Hayes Junior Member Posts: 1,164
    Hi Brian
    The NEC wasn't a command per say but was in the projectors OSD menu setup. After I changed it the units worked ever since.
  • bmitchellbmitchell Junior Member Posts: 41
    Hey Thomas,

    Not being on site, I can not say 100% if there is anything in the setup menus of the plasma.

    But knowing the person ( I have a lot of confidence in them) on site and they said they went through the menus and did not see anything, I have to believe that there is no setting that can be changed.


  • Thomas HayesThomas Hayes Junior Member Posts: 1,164
    Worth a shot. Once you figure it out can you post it?

    P.S. Sorry I spelled your name wrong. Bryan :o
  • pdabrowskipdabrowski Aussie Guy Posts: 184
    Hi Brian
    I had a problem like this with the NEC GT-5000, turns out I had to set the unit to a stand-by mode rather than ON/Off. Took awhile to figure it out because sometims if I burst the "ON" coomand it would work.
    Thanks for that tip Thomas - I tore my hair out trying to get a NEc projector working properly and resorted to re-cabling for RS232.
  • Thomas HayesThomas Hayes Junior Member Posts: 1,164
    Hi Bryan,(corrected spelling :) )
    Did you get the problem resolved? I was thinking about it and wondered if the unit gave RS-232 feedback when it was on, a status command or something. If so, then run an IR cable to the unit and just pulse the power on command via IR and all the other commands via the RS-232. Not fancy but a work around till you figure out the issue.
  • bmitchellbmitchell Junior Member Posts: 41
    I have a trouble ticket opened with Samsung. If/when I get an answer, I will update the forum.

    Also, I talked to another programmer and he was using PPM50M5H and the plasmas are doing the same thing, he also had to send the on command 6~8 times for it to work.
  • toddttoddt Junior Member Posts: 28
    I had this same problem with the Panasonic 3chip DLP projectors. The problem would only happen after they had been turned off for awhile. If you shut them off and a few mins later, they worked fine. If they would sit over night, they would not come on. I ended up sending the on commmand 3 times with waits between the sends. I guess they go to sleep and are like my wife, hard to wake up after sleeping all night. :)
  • bmitchellbmitchell Junior Member Posts: 41
    Ended up talking with Samsung (great tech support response!).

    Basically, the unit goes into a power save mode and when it first receives info on the RS232 port, the unit wakes up. However, the process of "waking up" can take several seconds.

    To resolve this (according to Samsung), you can poll the status of the unit on a regular basis and it should work by preventing the "sleep mode".

    Of course, we were not polling the unit, because it was on the 1 way RS232
    IR port (during testing , it was moved to a real RS232 port to see if that made any difference).
  • JohnMichnrJohnMichnr Junior Member Posts: 279
    Had the same problem with teh newer samsungs. Noticed that is was only when the samsung was left on PC1 (the input that turns off automatically.) Ended up sending the on command every 2 seconds until I received the power on responce.

    The older Samsungs never used to do that.

    I guess it's a feature...

    I've got a new project coming up with Samsungs - I'll try the polling stuff and see if it is any better.
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