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Sensing power status of a Motorolla settop box?

bobbob Independent ProgrammerPosts: 296
Hi guys,

I have a sattelite settop box which is almost impossible to sense the power on and off status! It has a soft power switch on the front which actually only turns on the display and a/v output, the box is always powered on, i.e. consumes the same amount of current so that a PCS won't sense anything else but always power on. Second, if the box is turned "off" (with the power button on the front panel) the video out is not turned off completely, the screen is black but there is a video sync signal present, so that a VSS2 will always show that video is present and the unit is on!

I am not allowed to switch this box entirely on and off with a relay on the back because it needs very long to boot if completely turned off from the power cable. I also can't swap outthe box, as this is the only box available from a local digital cable provider.

Do you know of any other solutions to sense the power status of such a unit? I have heard in the past about LED sensors which you stick on the display and that they will sense when the display is on and output +12v, but can't find anywhere such a device.

I have also heard that a VSS2 can be used to detect audio. As at least the audio on this box is present only when the box is actually running, so I have connected a VSS2, but it's +12v output is not constantly on (LED is flashing from on to off depending on the audio stream).

The box also has USB and firewire connectors on the back. As these connectors provide power for attached devices (no devices would be attached there at any time) I could use an adapter cable and sense the power pins, but I am not sure if power is applied to those USB and firewire ports when the unit is "powered on" from the front panel's power switch or generally when the box is connected to mains with the power cable (as is the video out and power to the box itself).

Have you seen such devices and have you any other ideas to sense the status of this beast?

Thanks and greetings,
Bob.

Comments

  • DHawthorneDHawthorne Junior Member Posts: 4,584
    I've used LED sensors to good effect. You can get them at Smarthome.com. The one on this page: http://www.smarthome.com/SOLUTION47.HTML, number 8013 will connect directly to an AMX IO port if you chop the connector off; power it off the buss like you would a VSS2.
  • bobbob Independent Programmer Posts: 296
    Thanks Dave! I went to that page, but couldn't see a picture of the LED sensor. Do you know what size they are? Are they unobstrusive like an IR flasher?

    Thanks again,
    Bob.
  • DHawthorneDHawthorne Junior Member Posts: 4,584
    They are like an IR flasher with one of those shields to block the IR receptor from outside IR. THe shield on them is about a one-inch square adhesive patch. If you peal it off, you are left with an element exactly the same in size as the inside of a flasher. So they aren't terribly inobtrusive out-of-the-box, but you could easily stick one in the plastic shell from a flasher, or even glue it on directly with some silicone adhesive.
  • Marc ScheibeinMarc Scheibein Junior Member Posts: 669
    Does that settop box have a SCART connector?

    In VCRs and DVDs, on the Scart connector there is a pin which will be set to 12V when the unit is turned on (waked from standby), so a TV will switch to the AV input. I'm imaging that the settopbox will work the same.

    At the moment I just can't remember what pin that is...
  • bobbob Independent Programmer Posts: 296
    Does that settop box have a SCART connector?

    In VCRs and DVDs, on the Scart connector there is a pin which will be set to 12V when the unit is turned on (waked from standby), so a TV will switch to the AV input. I'm imaging that the settopbox will work the same.

    At the moment I just can't remember what pin that is...


    Yes, there is a SCART connector on the back! I know this command pin which if set active the TV switches from the built-in TV tuner to the external A/V input! And the box when connected to mains but powered off do not instruct the TV to switch to the A/V input, only if it is turned on from the front panel's power button.

    This together with the LED sensor are great ideas - thank you guys!!

    Greetings,
    Bob.
  • bobbob Independent Programmer Posts: 296
    bob wrote:
    Yes, there is a SCART connector on the back! I know this command pin which if set active the TV switches from the built-in TV tuner to the external A/V input! And the box when connected to mains but powered off do not instruct the TV to switch to the A/V input, only if it is turned on from the front panel's power button.

    This together with the LED sensor are great ideas - thank you guys!!

    Greetings,
    Bob.

    This is pin 8 on the SCART connector. According to the links below, the TV will switch to TVmode when this pin goes Low (0-2V) and to AVmode when it goes High (9.5-12V). So, the settop box must set this pin to high when it is turned on and to low when it is powered off (goes in standby).

    Here some pinout tables for the SCART connector:
    http://www.proav.de/index.html?http&&&www.proav.de/data/cables/scart-pinout.html
    http://utopia.knoware.nl/users/eprebel/SoundAndVision/Engineering/SCART.html

    Thanks again!

    Bob.
  • shr00m-dewshr00m-dew Junior Member Posts: 394
    Being it has a scart connecter, I doubt you are in the US.. But maybe just in case, on the Motorola boxes here the outlet in the back can be set to turn off/on with the box power button. Run a 12V wall-wart to a relay for contact closure.

    Kevin D.
  • bobbob Independent Programmer Posts: 296
    I've tried pin 8 and GND on the SCART connector and there is indeed a voltage out when the settop box is powered on (10.5vdc) and no voltage when it is powered off. The problem is that those 10.5vdc can not drive a contact relay which I am then connecting to an INPUT port of an AXC-INP8 card. I have also tried to connect the voltage out directly to the INPUT port and set the INP8 port to voltage input but again nothing happens!

    Can anyone think of what might be the cause? I am just wondering why this 10.5vdc out can't close a 12vdc relay (checked the relay with a power supply and it works fine)!

    Any ideas as to what I can do?

    Thanks,
    Bob.
  • flcusatflcusat Junior Member Posts: 309
    DHawthorne wrote: »
    I've used LED sensors to good effect. You can get them at Smarthome.com. The one on this page: http://www.smarthome.com/SOLUTION47.HTML, number 8013 will connect directly to an AMX IO port if you chop the connector off; power it off the buss like you would a VSS2.

    Dave, this is a very old thread, but do you remember if this sensor uses 12V or you had to drop the voltage down to 5 volts? I tested yesterday a couple of sensors from Elan but they need 5 volts to work.
  • DHawthorneDHawthorne Junior Member Posts: 4,584
    flcusat wrote: »
    Dave, this is a very old thread, but do you remember if this sensor uses 12V or you had to drop the voltage down to 5 volts? I tested yesterday a couple of sensors from Elan but they need 5 volts to work.

    I've since switched to the Niles LS-1, which requires you put a 12V relay on the output, then use the dry contacts to trigger your IO port. The caveat is that you must use a relay that has a diode across the coil, or the inductive field caused by the relay opening will backfeed and put the LS-1 into a feedback loop (constantly chattering on and off). As I recall, however, the device from Smarthome could be connected directly to the NetLinx ... it has three wires: power, ground and trigger. Hook the power leads to the 12V and ground pins, and the trigger directly to the IO port.
  • jjamesjjames AMX Sustaining Engineer Posts: 2,901
    Just thought I'd add to this. Here's the piece we use; I'm not sure exactly how it's hooked up, but it works like a charm!

    http://www.elkproducts.com/products/elk-912.htm
  • Spire_JeffSpire_Jeff Formerly Caffeinated Programmer Posts: 1,917
    flcusat wrote: »
    I tested yesterday a couple of sensors from Elan but they need 5 volts to work.

    Elan has a piece called the SIM2 that works well with their sensors. One SIM2 will support 2 separate contact closure outputs and each output can be a single sensor or a logical combination of 2 sensors (AND/OR). We use them often because they work and they are professional looking. I could probably make a sensor with relays and what not using Radio Shack parts, but in the long run, this saves me time and it looks good.

    It also allows me to easily use LED, Audio, or Video sensing by just using the correct sensor. I can even use one output on the SIM2 with an LED sensor, and the other output can be the logical AND of an Audio sensor and a Video sensor. (I don't need to burn up 2 inputs on the AMX to verify Audio and Video).

    Just my 2 cents :)

    Jeff
  • CT-DallasCT-Dallas Junior Member Posts: 157
    Does your motorolla box have a switched outlet on the back? I recently plugged a universal power supply into the back of that and dropped the output voltage to 12v or so. I then ran that to an I/O on the master. The outlet is a great indicator of the STB power state - and we have not had a problem with it for over 6 months now.

    I pick the plugs up at walmart for roughly $10 in the electronics dept.
  • jjamesjjames AMX Sustaining Engineer Posts: 2,901
    CT-Dallas wrote: »
    Does your motorolla box have a switched outlet on the back? I recently plugged a universal power supply into the back of that and dropped the output voltage to 12v or so. I then ran that to an I/O on the master. The outlet is a great indicator of the STB power state - and we have not had a problem with it for over 6 months now.

    I pick the plugs up at walmart for roughly $10 in the electronics dept.

    Exactly what we do with the Elks. Just gotta be sure to change the settings of the STB; by default ours come "always on".

    The Motorolas and S.A. boxes that we've dealt with all have this "feature."
  • flcusatflcusat Junior Member Posts: 309
    CT-Dallas wrote: »
    Does your motorolla box have a switched outlet on the back? I recently plugged a universal power supply into the back of that and dropped the output voltage to 12v or so. I then ran that to an I/O on the master.


    Doesn't the voltage at the I/O ports need to be dropped to around 5 Volts?
  • TworhythmsTworhythms Junior Member Posts: 51
    I use a 6 Vdc transformer with a relay wired to the IO port. I don't like sending power to the NI unless absolutely necessary. I let the NI detect the closed state of the relay and haven't had any issues for years doing it this way :)
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