Back to basics: How does x10 work?

Hello all,

Here is an x10 Introduction, a comprehensive description on how x10 works and some common questions I hear all the time. I decided to post a quick presentation to help everyone understand the basics of x10.


Introduction

Let's start with a basic introduction to the X10 protocol. This KnowledgeBase will not go into the technical details about how X10 signals are transmitted onto the house wiring and the timing sequence involved when transmitting information. If you are interested in more details about the protocol, please go to the following web page:

http://www.x10.com/support/technology1.htm X10 Powerline

Communication In A Nutshell

In the past, if you wanted to be able to control certain lights and appliances from one location, you would have to run hundreds of feet of wire to route the power switches of each device to one location. Using X10 modules, you don't have to do this, since the X10 House/Unit codes and commands are transmitted over your existing house wiring.

House And Unit Codes

In order to control specific devices, all modules are assigned an address, which consists of a House and Unit code. There are 16 House codes (A through P) and 16 Unit codes (1 through 16).

Each House code has 16 Unit codes. This means there are 256 possible addresses. House/Unit codes are referred to in the following manner: A5, C7, M13, P4, etc. When you wish to turn on an X10-controlled lamp, you have to tell the Lamp Module controlling that lamp to turn on. The Lamp Module is monitoring the powerline for a command specifically addressed to it. In other words, any command sent must be preceded by an address matching the Lamp Module's address.

Let's say the Lamp Module's address is set to A5. The Lamp Module will not respond until it "sees" the A5 ON command on the powerline. Note: There are exceptions to this rule. Most modules will respond to special commands that are addressed to a large group of modules.

One example is the All Lights On command. Any lamp modules set to a specific House code (i.e. House code "A") will turn on when this command is transmitted. Confused?We understand that everyone has a different way of learning, so these concepts may be difficult for some people to understand. If so, let's try looking at this a different way.

Imagine you have a room that contains groups of people. In fact, there are 16 groups of people. In each group, there are 16 people. You are at the front of the room and your job is to issue instructions to these people. Some of the instructions you are going to issue are for specific people and others are for entire groups of people. To prevent miscommunication, every group has been assigned a letter (A through P), and each person has been assigned a number (1 through 16). Each person wears a sign around their neck that has the letter and number they have been assigned. Your first instruction is for a man you had spoken with earlier that day. His sign reads "A7".

To ensure that he is the only one to respond to your instruction, you say, "A7 take one step forward." The man wearing the A7 sign obeys your instruction. No one else in the room follows this instruction. This example parallels commanding a specific X10-controlled lamp or appliance module (set to A7) in your home to turn on or off.

Your second instruction is a little different. It involves having all the women in the "J" group sit. To cause this to happen you say, "All women in the 'J' group sit down." Every woman in the "J" group sits on the floor. This example is comparable to the All Lights On. Lamp Modules assigned to a certain house code (in this case J) would respond. Lamp Modules assigned to a different house code would not respond. Appliance Modules do not respond because they are a different type of module.

X10 HOME AUTOMATION INSTALLATION

To best demonstrate the X10 communication system, we will explain one of the simplest X10 configurations. It consists of a remote, a Transceiver, and a Lamp Module. For our example we will use the following products:

• Palm Pad Remote (HR12A) • Transceiver (TM751) • Lamp Module (LM465)

Component Background- Let's take a moment to go over the basic descriptions and functions of the components we will be using in our example. Palm PadThe Palm Pad Remote is a battery-operated, radio frequency (RF) transmitter. It is used for turning devices on and off, and it can send dim or brighten commands to Lamp Modules and Wall Switch Modules. The Palm Pad can control all House/Unit codes (256 possible codes); however, its House code dial can only be set to one House code at a time.

Transceiver-The Transceiver, which is short for transmitter/receiver, is an AC-powered device with an antenna connected to its side. The Transceiver has three functions: 1. Receive X10 RF commands. 2. Transmit X10 powerline commands. 3. Function as an Appliance Module. The Transceiver receives the RF command signals sent from the Palm Pad. It decodes the signal and then transmits the command signals on the house wiring in the proper format to reach an X10 module, such as a Lamp Module. The Transceiver acts as a kind of "middle-man" between the PalmPad and the Lamp Module.

Lamp Module-The Lamp Module is a receiver. It cannot transmit. Instead of using the physical switch on a lamp, the Lamp Module acts as the switch and also adds the capability of dimming and brightening the light. The Lamp Module can only be used to control incandescent lamps. It cannot control inductive loads, such as fluorescent lights, low-voltage lights, or fans. For those types of items an Appliance Module should be used.

Confusing Terminology- Transmitter and Transceiver Receiver Setup Setup of our example is quick and easy. Configuring The Palm Pad 1. Insert four AAA batteries into the Palm Pad's battery compartment. 2. Set the House code dial on the Palm Pad to "A". The dial is located in the bottom left corner of the remote. 3. Set the Unit Selection Switch to "1-8". The switch is located in the bottom right corner of the remote. 4. Press one of the ON or OFF buttons. You should see the LED at the top of the remote blink. This confirms the Palm Pad is operating.

Configuring The Transceiver -1. Set the House dial on the face of the unit to "A". 2. Temporarily plug an incandescent lamp into the outlet on the bottom of the TM751 (first make sure the lamp's power switch is ON). 3. Plug the Transceiver into an AC outlet. 4. Press the ON/OFF button on the face of the unit. You should hear the relay inside click, and the lamp will turn on or off. This verifies that the Transceiver is connected to power and is ready to send and receive commands. 5. Press the ON/OFF button again until the relay (and the lamp) is off. 6. Extend the Transceiver's antenna. Note: The TM751 Transceiver does not have a Unit dial. It is preset to Unit code 1.

Configuring The Lamp Module-

1. Set the House dial to "A".

2. Set the Unit dial to "2".

3. Locate the lamp you wish to control. The Lamp Module is specifically designed to control lamps using incandescent bulbs. If you wish to control a fluorescent or low-voltage lamp, an Appliance Module must be used. Note: Don't forget, the Transceiver functions as an Appliance Module.

4. Plug your lamp into an AC outlet.

5. Turn the lamp on. Note: The lamp must have a regular ON/OFF switch. Do not use the Lamp Module for lamps that already have a dimmer on them.

6. Leave the lamp's switch in the ON position. Unplug the lamp.

7. Plug the lamp into the Lamp Module. The Lamp Module will now function as the switch for the lamp.

8. Plug the Lamp Module into an AC outlet.

Establishing Basic X10 Communication- We are now ready to test the system. You will notice from the previous procedures that all equipment has been set to the same House code. If the devices were not set to the same House code, this example would fail to work. We will now confirm that the Transceiver will respond to commands sent by the Palm Pad Remote. Confirming RF Communication 1. Since the default Unit code for the Transceiver is 1, we will send the ON command for Unit 1. Press the ON button in the top row of the Palm Pad (row 1 controls Unit 1, row 2 controls Unit 2, etc.).

If the Unit Selection Switch is set to "9-16", the top row is unit 9, the second is 10, and so on. 2. You should hear the relay inside the Transceiver click on. The click confirms that the Palm Pad is transmitting properly and the Transceiver is receiving and responding to commands.

If you do not hear the click, press the OFF button on the remote instead. The Transceiver's relay may already be in the ON position. If you still have a lamp plugged into the Transceiver, it should turn on or off as you send the commands. Testing The Lamp Module 1. Press the ON button on the Palm Pad for Unit 2 (second row). 2. A moment later the light should turn on. 3. Press the OFF button for Unit 2. 4. A moment later the light should turn off. Note: Allow at least one to two seconds between each command you send. There will be a slight response delay depending on various conditions in your home, such as the physical length of the powerline wire between the Transceiver and the Addressable Power Supply.

Well, there you have it, some of the basics covered. All other X10 products are usually variations of this basic setup.

Behind The Scenes

So the example worked, but what does it all mean? How does it all work? When a button on the Palm Pad is pressed, it transmits an RF signal (at 310MHz, if you were wondering). The Transceiver detects the RF signal and extracts the information (the House/Unit code and command).

Next, the Transceiver encodes the House/Unit code and command into the proper X10 powerline carrier format and transmits it on your house wiring. If the House/Unit code matches the Transceiver's House/Unit code, it will respond to the command (ON/OFF only). The powerline command travels along your house wiring.

The Lamp Module is monitoring the powerline for X10 commands. When it detects an X10 command, it checks to see if the House/Unit code matches its House/Unit code. If it matches, it follows the command given, provided it is a command that the Lamp Module can accept. Confused?Let's think of the three devices (Palm Pad, Transceiver, and Lamp Module) as people.

The Palm Pad is a person who speaks French. The Lamp Module is person who speaks English. The Transceiver is a person who speaks French and English. The French person wants to tell the English person to turn on the light switch. Since they speak different languages, the English person will not understand any instructions to turn on the light. This is where the French-English speaker comes in to translate. This is the essence of the X10 addressable module system.

Caveats- For general use, you should not plug any X10 modules (Lamp Modules, Appliance Modules, ActiveHome Interfaces, Addressable Power Supplies, etc.) into surge protectors, power strips, plug splitters, or extension cords because these devices can filter or significantly attenuate (reduce) X10 powerline commands. This could result in intermittent communication.

Questions and answers:

Since there are 256 possible addresses, am I limited to 256 controlled devices?

No. There are 256 addresses to allow you to control a large number of devices individually. In most homes, there are a number of lights that are always turned on around the same time of day. With X10 modules, each light could be assigned an individual address, but turning on a number of lights individually would take some time. Instead, all of the lights could be set to the same address. Now only a single command is sent to turn on the group of lights.


Q:Do modules of the same House code have to be located in the same area of my home?

A:No. You can have modules set to different house codes located anywhere you choose.

Q:Do you sell video senders and cameras that can transmit more than 100 feet?

A:No, the Federal Communications Commission (FCC) sets the 100-foot limitation.

Q:Is an addressable power supply available for the Video Receiver?

A:At this time, no.

Q:Can more than one receiver be used to receive the same signal for output to additional TVs or VCRs?

Yes. An unlimited number of receivers may be used.

Q:Can more than one video transmitter be used?

A:There are four transmission channels available; therefore, up to four transmitters can be operating at the same time, as long as they are not located too close to each other.

Q:I own other 2.4GHz equipment (i.e. cordless phone, wireless LAN) and it interferes with the video signal. What can I do to fix this?
A:You might want to check the other device's manual for the frequencies of each channel that it uses.

Our video equipment uses the following frequencies:
Channel A: 2.411 GHzChannel B: 2.434 GHzChannel C: 2.453 GHzChannel D: 2.473 GHz

We recommend using the frequency on the other device that is farthest from channel A or D, depending on which side of the band the other device is transmitting. Other than that, your remaining option is to discontinue use of the device while using our video equipment.

Q:When using your Video Sender, I receive an unacceptable picture on my TV. The picture dims/brightens, tears (part of the picture moves to the left while another part goes to the right), displays noise, etc. Why is this happening?

A:The problem may be due to Macrovision (AKA copy protection). Try playing a recording of a show taped from your TV. If the playback is fine, chances are you were watching a purchased movie (either VHS or DVD) that uses copy protection.

The Macrovision web site states that some or all of the following characteristics will appear: dim and/or noisy pictures, loss of color, intermittent or permanent loss of video, and picture tearing. If you would like more information about Macrovision, the address is www.macrovision.com.

Q:I thought the cameras were supposed to be wireless. My XCam2 has a power cord coming out of it. Why?

A: Please see the Confusing Terminology section for "Wireless."
What picture format do the cameras output (JPEG, bitmap, etc.)?

Q: Our cameras are CMOS, not digital. They output an NTSC composite video signal (310 TV lines, 30 frames per second).
Are your cameras waterproof?

A:They are weather resistant if the clear plastic lens cap is fitted. Rain is acceptable, but submersion in water is not.

Q: My camera's image is blurry. How do I adjust the focus?

A: XCams are shipped preset to be in focus for normal use, but if you want to change the focus you can remove the clear plastic cover and rotate the inner portion of the lens. It might be a bit tight. Try turning it counterclockwise first. If you turn it clockwise do not force or over tighten it. Replace the clear plastic cover if you are using the camera outdoors.

Come visit http://www.x10captain.com/ for the latest products and information. As a consultant, I can provide you with help and send you in the right direction for all of your home automation ideas and needs. Contact me at benstern@x10captain.com