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Infrared Distribution Tutorial


by Jeff Fisher

This is a brief introduction to products that transport infrared device control signals.

IR Distribution via 3-4 Dedicated Conductors

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There are three main parts to a hardwired infrared distribution system:

  • Infrared Receiver (Pickup) This device picks up the infrared signal from your remote control just like a TV or VCR. It encodes the infrared signal into a signal suitable for transmission. Receivers must be located in the room you wish to use the remote control. The wire from the receiver to the connecting block needs at least three available conductors and can be several hundred feet long. Both quad wire and category 5e wire work fine.
  • Connecting Block This is simply a place for all the parts to plug in or connect to. Connecting blocks are usually classified based on the number of outputs (how many IR emitters can connect to the block) Amplified connecting blocks can generally support more outputs. All connecting blocks can support many IR receivers wired in parallel. Connecting blocks are usually located near the equipment that is to be controlled, along with the power supply and emitters.
  • Infrared Emitters IR Emitters generally "stick" onto the front of the device you want to control. Therefore you need one emitter for each device. "Dual" emitters have two emitters and one plug, so they only take up one jack of the connecting block. "Blink" emitters blink visibly as well as infrared, so they are easier to troubleshoot. All emitters come with long cords and extra double-stick tape. "Blast" style emitters, where one emitter blinks into several devices, are usually less reliable but can be used when the environment is tightly controlled and IRPRISMs are used on the receiving devices to improve reception.
  • Power Supply A single power supply will power most IR distribution systems. A small 12VDC 300mA supply is all that is needed in most cases. In larger systems, use a 12VDC 1500mA power supply. For maximum reliability, always use a regulated power supply.

IR Distribution via Coaxial Cable

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We recommend not using the IR over coax method if there is any way to get dedicated wiring between your locations. IR over coax does work, and is rock-solid reliable...if your installation is either simple or you really know what you're doing. See below for information on the pitfalls of IR over coax.

The Parts

There are five main parts to a coax-based infrared distribution system:

  • Infrared Receiver (Pickup) This device picks up the infrared signal from your remote control just like a TV or VCR. It encodes the infrared signal into a signal suitable for injection. Receivers must be located in the room you wish to use the remote control. The receiver plugs into the coupler. Any receiver can be used, but the 17294 kit comes with a 29110 style receiver.
  • Injector The injector does three things:
  1. It passes the TV signal from input to output.
  2. It injects the signal from the infrared receiver to the side of the injector that goes "upstream" to the coupler.
  3. It connects power from the power supply to the infrared receiver.

The17294 kit includes an INJ94 injector. They are also available separately here.

  • Power Supply A small 12VDC 300mA power supply is required at the sending end. For maximum reliability, always use a regulated power supply. The 17294 kit comes with a power supply.
  • Coupler The coupler does two things:
  1. It passes the TV signal from input to output.
  2. It extracts the infrared signal from the downstream injector to drive one or more infrared emitters.

The 17294 kit includes a CPL94B coupler. They are also available separately.

  • Infrared Emitters IR Emitters generally "stick" onto the front of the device you want to control. Therefore you need one emitter for each device. "Dual" emitters have two emitters and one plug, so they only take up one jack of the connecting block. "Blink" emitters blink visibly as well as infrared, so they are easier to troubleshoot. All emitters come with long cords and extra double-stick tape. "Blast" style emitters, where one emitter blinks into several devices, are usually less reliable but can be used when the environment is tightly controlled and IRPRISMs are used on the receiving devices to improve reception. The 17294 kit includes two emitters. They are also available separately here.

The Pitfalls

IR over coax puts a DC signal on the coax. There are three pitfalls you must be aware of when using IR over coax:</p>
  • It will not work on a cable carrying satellite TV signals (which also puts DC on the coax.)
  • You can't have any non-dc passing splitters between the injector(s) and the coupler. These will block the infrared signal. Note that splitters are often in hard-to-reach locations or even buried in walls. All the splitters we sell are DC passing. Many cheap splitters are not.
  • Anything connected to the video distribution system between the injector(s) and the coupler must either have an injector or a DC block installed. A TV or a VCR connected directly to the coaxial cable containing the IR signal will "short out" the signal. (The injector has a built-in DC block.)

Multiple Receivers

Finally, as implied above, you can have more than one IR receiver. Use the 17294X expansion kit for each additional receiver if you wish, but take careful note of the pitfalls above.

IR Distribution Through a Structured Wiring Cabinet

If you have a structured wiring cabinet and you only have one or two phone lines, you can easily distribute IR through your home!

In this scheme, you'll be using pairs 3 and 4 in the cat5 cable that you use for your phone line(s). Since the telephone line hub in your cabinet buses all phone lines to all locations, these wires are already bussed throughout your home! We can put the infrared signals on those lines anywhere with an IR pickup, and extract them from anywhere with a connecting block and emitters. We can even power everything from the cabinet!

Here's the pin-out we'll be using:

DescriptionRJ45 PinCat5 Wire Color29110 Wire Color
+12VDC1White/GreenRed
Ground2GreenBlack
Signal7White/BrownWhite
Unused8BrownN/C


Here's how to set it up: You'll need a modular plug crimper to put modular plugs on the IR pickup.

  • Use a 12VDC regulated power supply to put power on the green pair. If you have a DC power buss, such as the Leviton DC Power Module, in your cabinet, simply connect a pair of wires from that to the green pair input punch-down of your telephone module. Otherwise you can cut the connector off of the end of a power supply and punch those wires onto the green pair input. Alternatively, you can power everything from the connecting block.
  • Replace the 1/8" stereo plug on each IR receiver with a modular plug. Use the pin-out above. (Red to pin 1, black to pin 2, and white to pin 7.) Plug the IR receivers in where you want them. If there is already a phone plugged into the jack, use an 8 position "Y".
  • Install a modular plug on one end of a length of cat5 cable. Attach the other end to the terminals of your connecting block. (White/Green to +12, green to ground, white/brown to signal.)


The orientation of the modular plug is as follows:

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IR Distribution via RF

Over the years many products have come out that send infrared signals via radio frequency (RF.)

  • Some original equipment remote controls and equipment have had built-in RF transmitters, such as Sony's older satellite receivers and remotes. The manufacturers seem to have moved away from this approach in recent times. The problem with this approach (other than the general RF problems noted below) is that the remote cannot control any other pieces of equipment back at the "headend."
  • The popular X-10 "Powermid" product (and RCA, Recoton, and Terk knockoffs) has two stationary pieces; the IR receiver/RF transmitter, and the RF receiver/IR transmitter. You point your remote at the first part, it transmits RF to the other part, which "blasts" the IR to the component you want to control.
  • Lastly, there is the style of remote control extender that attaches in some manner to your existing remote. A second unit blasts the IR into the devices you wish to control. Terk's Leapfrog Remote Control Extender operates in this manner.


The advantages of the latter two styles of infrared distribution are that they are inexpensive and easy to install. The disadvantages are numerous.

  • Although it works fine in many circumstances, RF transmission is subject to interference. Depending on your RF environment, these devices may or may not work for you. Note that reducing the distance between the transmitter and receiver does not necessarily help with interference problems: The interference continues to bleed through during the infrared code transmission, reducing the target device's ability to decode commands. We stopped selling the X-10 Powermid due to the number of buyers that experienced interference problems.
  • Range can be an issue as well. Some systems simply don't have the range necessary to make it from one end of a ranch home to the other.
  • Lastly, as with all RF devices, the orientation and placement of devices can be somewhat "fussy." The perfect spot for you may be the absolute worst spot for RF transmission or reception, while the best spot for transmission and reception may be hovering in midair only one foot to the left. This problem can be even more frustrating when the transmitter is attached to the remote control. You may find that the arm of your favorite TV chair is a "dead spot."


All that having been said, if the RF system works for you, it is the simplest and least expensive approach.

Manufacturers

We carry infrared distribution equipment from several manufacturers, including Channel Vision, Audioplex Technology, Xantech, and Buffalo Electronics. Xantech has the most complete line and has been around the longest. Audioplex is often the most expensive but has unique products of unparalleled quality. Channel Vision produces good quality equipment at reasonable prices. And Buffalo produces the least expensive components.

We do recommend sticking to one vendor's equipment as much as possible. While we don't know of any incompatibilities between different vendor's products, we do seem to get more tech calls about problems when there is a mix of products in use. This is especially true of receivers and connecting blocks.

Jeff

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