TV,DVD feedback

etrujillo

Anyone know how can I obtain feedback at least I need if they are on or off
They havent got RS232.

DHawthorne

etrujillo wrote:

Anyone know how can I obtain feedback at least I need if they are on or off
They havent got RS232.

You could try a power current sensor (AMX part PCS) , but I wouldn't expect it to be sensitive enough for the DVD; it would probably be fine for the TV. The only alternative is something to stick on the power LED to detect that it's lit, which won't work if it's just a dual-color LED. You can find those at www.smarthome.com . If the TV has a video output, you can use a sync sensor (AMX VSS2), and if the DVD doesn't output when it's off (some do the blue screen thing), you can use it on that too.

Here's the real question: do you need feedback to determine whether someone manually turned the devices on or off, or is this strictly for control purposes? If it's to detect manual operations, the above are pretty much your only options. If you need this strictly for control, however, you have a few more choices.

The first is to get discrete power commands; they are available for about 90% of the stuff out there. If you know you sent a power on, you can just set the feedback to on. As long as the equipment didn't simply fail, it will be right. If there are no explicit discrete commands, you can sometimes find a workaround. For example, I have yet to see a DVD player that didn't power on when you hit the play button. So you know play will turn it on, and when you want to turn it off, you hit play, wait 5 seconds, then hit the power toggle. Similarly, many TV's will turn on with a channel command, and if you send a 0, since that is always an invalid channel, it will turn it on, but won't actually change the channel (some cable and sat boxes work the same way). It all depends on the specific equipment.

etrujillo

TV, DVD feedback

My problem is when someone turns on TV manually

thank?s

vining

Nles makes the LS-1 light sensor which works good for the power leds for cable boxes and the like and if your not using the toslink jack on devices that is supposed to work although I'v never tried. The PCS or PCS2 works well and on most devices it can be adjusted to tell the difference between OFF, ON, Play or Pause. Actually Play, Fast forward and Rewind draw similar current on DVD and CD's players that I use. So if set properly you can tell if it ON and if ON whether it's in Stop or Pause or Play, FF or Rewind.

VLCNCRZR

Amx Tvs

If your TV is a CRT type display, you can use the AMX TVS
in conjunction with any IO port on an AXCESS or NetLinx
controller.

This device actually sense the electromagnetic fields when
a monitor or TV is operating.

Darkside

We *always* take devices like DVDs and VCRs and send them straight to the workshop. Here the techs insert an IR diode and a tellback relay.

The IR diode inside the box ensures it doesn't get knocked off.

More importantly the tellback relay (FELV coil) is connected to one of the devices control lines that goes hi or low depending on the power state. Protection diodes for back emf are always fitted to the coil.

The relay then simply fires dry contacts that are connected to the IO port of the processor.

With respect to TVs, the power can easily be tracked with the PCS or the above method, however, with some models we have had to track the status of the SOURCE as well. The kids in the tech dept apply the same principle as above and drag out lines that go hi and lo depending on the source that is selected. This is great for TVs that have a 'cyclic' source selection (not discrete selection) as the io port can then let the system know the story.