IR distribution help needed -- isolating two remote receivers - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 14 Old 11-20-2012, 11:58 AM - Thread Starter
Senior Member
 
cowger's Avatar
 
Join Date: Jul 2007
Location: Northern California
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 43
Hi,

I've been struggling with a problem and I'm hoping that people smarter than me can help me figure out a solution.

Here is a picture of a coax-based IR distribution network I have running in my house. I have all my DVRs centralized in one place and use an HDMI switch to send content out to various rooms. Each room with a monitor has an IR receiver which injects the IR onto coax (which has been abandoned for video distribution now; its only use is to distribute IR).

IRdistribution.jpg

All but one aspect of this (see below) works well; the DirecTV DVRs are all set up to only pay attention to their specific remote; a universal remote in each room can control the HDMI switch remotely and then assume the personality of the appropriate remote.

I have two Onkyo receivers; one upstairs in the TV room and one near the HT to serve that room, housed in the same rack as the DVRs and HDMI switch. Each component in the rack gets a copy of whatever is inserted onto the IR distribution network.

The problem is this: When I send commands to the receiver in the TV room (Onkyo Rcvr #1), the other receiver is getting a copy of that signal and responds as well. Thus, controlling the receiver in the TV room messes up the viewing in the HT.

Any ideas for this? I suppose a brute force way would be to set up a completely separate IR network for each, but I'm hoping for a more elegant solution...

Help Mr. Wizard! smile.gif
Bryan
cowger is offline  
Sponsored Links
Advertisement
 
post #2 of 14 Old 11-20-2012, 12:55 PM
Member
 
Vyrolan's Avatar
 
Join Date: May 2012
Location: Chicago, IL
Posts: 87
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Well...firing from the hip here, but you could have your distribution system not send commands to the Onkyo in the rack. That would prevent it from being controlled in the TV Room. Then setup a separate IR extender from the HT to the rack to allow it to be controlled. You'd have two IR receiver eyes in your HT...one for controlling everything in the rack except the Onkyo, one for just the Onkyo. If your HDMI extender feeding the HT display has IR capabilities (or you change to one that does), you could just use that.

Beyond that, I'm not sure what else you could do...I'm assuming your IR equipment doesn't have any kind of routing built-in or you would just be using that.

I guess you could add a little IR routing piece between the distribution and the Onkyo in the rack. It would default to off so that TV Room doesn't control it, and the remote for the HT would have to be programmed to "enable, send command, disable" for everything. You'd run the risk of someone in the other room sending a command at the same time, and it'd be pain to get it working well for push and hold stuff like Volume control.
Vyrolan is offline  
post #3 of 14 Old 11-20-2012, 05:46 PM - Thread Starter
Senior Member
 
cowger's Avatar
 
Join Date: Jul 2007
Location: Northern California
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 43
Thanks, Vyrolan, for the thoughtful suggestions! I agree that adding a 2nd, completely independent IR network, with a 2nd receiver eye in the HT, is a workable solution.

However, your post got me thinking, and I'm wondering if I could use a diode here to help me... Below is a new diagram with 3 new components in red:

IRdistribution2.jpg

My thinking is this: Split the signal coming from the HT IR receiver, send one side directly to the HT-dedicated components (namely Rcvr #2 and the BR player), and send the other side on to the normal IR network. (BTW, I already tried this w/o the diode, not realizing that the signals from the TV room would crawl right back up the coax network, through the splitter, and over to Rcvr #2.) However, if I could add a diode in that second line, it would prevent signals coming from the TV room receiver from getting to Rcvr #2, yet both sources still make it to all DVRs and the HDMI switch.

The question is whether an inline diode would work and you can block a signal like this or not. Has anyone ever looked at the IR signal after it's injected onto coax? What kind of voltage do they run peak-to-peak? Enough to overcome the 0.7V diode forward drop?

I'll grab a diode tomorrow, solder it (and a ground) between a couple coax connectors, and see what happens...

Bryan
cowger is offline  
post #4 of 14 Old 11-20-2012, 07:48 PM
AVS Special Member
 
jautor's Avatar
 
Join Date: Jun 2001
Location: Houston, TX
Posts: 8,032
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 228 Post(s)
Liked: 365
IR over coax is either 5V or 12V signalling depending on the system. Is this one of the Xantech or ChannelPlus systems? If it's a Xantech XtraLink with the IR receivers powered at the zone end, adding a splitter and another CPL18 for the theater side would get you there (no need for the diode)... If it's a ChannelPlus 5V setup powering the IR receivers at the coax panel, I don't think your diode trick is going to work...

Rock Creek Theater -- CIH, Panamorph, Martin Logan, SVS PB2000, Carada Masquerade, Grafik Eye, Bar table, Green Glue, JVC RS50 
Theater build photos: http://photobucket.com/autor-ht
jautor is online now  
post #5 of 14 Old 11-21-2012, 06:11 AM
 
SAM64's Avatar
 
Join Date: Apr 2011
Posts: 1,592
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked: 74
I don't see how the baseband data from a receiver can drive an IR LED directly, without the required modulation.
SAM64 is offline  
post #6 of 14 Old 11-21-2012, 08:23 AM - Thread Starter
Senior Member
 
cowger's Avatar
 
Join Date: Jul 2007
Location: Northern California
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 43
Quote:
Originally Posted by jautor View Post

IR over coax is either 5V or 12V signalling depending on the system. Is this one of the Xantech or ChannelPlus systems? If it's a Xantech XtraLink with the IR receivers powered at the zone end, adding a splitter and another CPL18 for the theater side would get you there (no need for the diode)... If it's a ChannelPlus 5V setup powering the IR receivers at the coax panel, I don't think your diode trick is going to work...

It's all Xantech stuff: INJ94 injectors at each zone and CPL94Bs at the rack (equipment) end. I couldn't find what a CPL18 is...

I think you're suggesting that if I rig up the configuration show directly above but without the diode, it should work. If so, I tried that, but Rcvr #2 still gets the Onkyo signals from the TV room, since the coax network acts just like a DC distribution and everything flows everywhere.

Bryan
cowger is offline  
post #7 of 14 Old 11-21-2012, 08:24 AM - Thread Starter
Senior Member
 
cowger's Avatar
 
Join Date: Jul 2007
Location: Northern California
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 43
Quote:
Originally Posted by SAM64 View Post

I don't see how the baseband data from a receiver can drive an IR LED directly, without the required modulation.

Sorry, my diagram is very simplified. There are INJ94 injectors in each of the zones, which are powered by 12VDC supplies and this generates enough power to drive all the emitter LEDs. Hope this answers your question...

Bryan
cowger is offline  
post #8 of 14 Old 11-21-2012, 08:28 AM
 
SAM64's Avatar
 
Join Date: Apr 2011
Posts: 1,592
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked: 74
Quote:
Hope this answers your question...

it doesn't...those injectors don't modulate the signal at all.
SAM64 is offline  
post #9 of 14 Old 11-21-2012, 08:38 AM - Thread Starter
Senior Member
 
cowger's Avatar
 
Join Date: Jul 2007
Location: Northern California
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 43
Quote:
Originally Posted by SAM64 View Post

it doesn't...those injectors don't modulate the signal at all.

Okay, sorry, then I don't understand the question. "Modulation" to me means bringing the low-frequency IR signal up to TV channel frequencies. My understanding of this IR distribution is that it all runs on baseband and there's no reason to modulate, but I'm clearly missing something...
cowger is offline  
post #10 of 14 Old 11-21-2012, 09:36 AM
 
SAM64's Avatar
 
Join Date: Apr 2011
Posts: 1,592
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked: 74
The signal applied to the IR LEDs is modulated, usually around 38KHz.
The signal from the receiver is baseband...the modulation is removed by the receiver/demodulator.
SAM64 is offline  
post #11 of 14 Old 11-21-2012, 09:51 AM - Thread Starter
Senior Member
 
cowger's Avatar
 
Join Date: Jul 2007
Location: Northern California
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 43
Quote:
Originally Posted by SAM64 View Post

The signal applied to the IR LEDs is modulated, usually around 38KHz.
The signal from the receiver is baseband...the modulation is removed by the receiver/demodulator.

Okay, got it, that's great to know.

So the problem is that I've mis-labeled things in the diagram above. Where I say "IR splitter" it should read "demodulator". And the receivers in the zones should have a "modulator" box shown (which they do have).
cowger is offline  
post #12 of 14 Old 11-21-2012, 11:55 AM
AVS Special Member
 
jautor's Avatar
 
Join Date: Jun 2001
Location: Houston, TX
Posts: 8,032
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 228 Post(s)
Liked: 365
Quote:
Originally Posted by cowger View Post

It's all Xantech stuff: INJ94 injectors at each zone and CPL94Bs at the rack (equipment) end. I couldn't find what a CPL18 is...

Ack, I think I grabbed the wrong part #... Ok, with the XtraLink2 setup, you can just buy one more CPL94. Where you have the "DC passing splitter", you split, and place the new CPL94 on a leg to plug your theater-dedicated emitters. I think that will work...

Jeff

Rock Creek Theater -- CIH, Panamorph, Martin Logan, SVS PB2000, Carada Masquerade, Grafik Eye, Bar table, Green Glue, JVC RS50 
Theater build photos: http://photobucket.com/autor-ht
jautor is online now  
post #13 of 14 Old 11-21-2012, 01:12 PM - Thread Starter
Senior Member
 
cowger's Avatar
 
Join Date: Jul 2007
Location: Northern California
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 43
Quote:
Originally Posted by jautor View Post

Ack, I think I grabbed the wrong part #... Ok, with the XtraLink2 setup, you can just buy one more CPL94. Where you have the "DC passing splitter", you split, and place the new CPL94 on a leg to plug your theater-dedicated emitters. I think that will work...
Jeff

Ah, I see what you're saying. I'll give this a shot and let you know!

Bryan
cowger is offline  
post #14 of 14 Old 11-22-2012, 10:42 AM - Thread Starter
Senior Member
 
cowger's Avatar
 
Join Date: Jul 2007
Location: Northern California
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 43
Well, believe it or not (and I'm still somewhat shocked myself), my hokey-pokey diode trick works! I implemented as shown below and got all the functionality I was looking for.

finalconfig.jpg
Now IR commands from the TV Room don't make it to Rcvr #2 (and the BR player), but commands from either zone make it to the DVRs, etc. biggrin.gif


Here's how I put a diode inline with a short piece of coax:

pic_a.jpg

pic_b.jpg


jautor, I did try out what I think you were suggesting, but unfortunately that didn't work. Here's what I did; the red arrows represent my idea of how TV Room commands were still making it to Rcvr #2:

nowork.jpg

Perhaps I didn't implement things the way you were thinking, but in any case, it's a happy ending for <$4 of parts from Radio Shack.

Thanks to all who helped me get through this!
Bryan
cowger is offline  
Reply Home A/V Distribution

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off