If one were to browse the Usenets at any one time, one would notice a proliferation of arguments about X10 versus CEBus home automation products. With so much bantering back and forth, one could walk away even more confused, still wondering which technology is really better? I know I became more confused.  Many people have strong arguments either way and are quick to discredit opposing but well researched points of views. But very few have ever had the privilege to "test drive", or better yet, to live with both. I decided to try out both systems, side by side.  I have had the "dual experience" and I would like to share my experiences with you about these two power line carrier solutions.

Before I get into a more thorough discussion of my experiences with the two technologies, I feel it is appropriate to offer a little background about my company. HomeTek, Inc. is a relatively new automation and energy management company that deals primarily in the residential market with an emphasis on installing systems for those with physical disabilities or impairments.  My business partner and I are both degreed electrical and software engineers with over 40 years of combined experience in the design and manufacture of electronics. We are not electricians but we do have one on staff to ensure we install our products per the electrical codes. We are electronic designers who pride ourselves in offering our customers creative and custom solutions for all automation needs. There is literally no product for which we cannot design and build the interface or the software. This is our passion. This is our value.

We install X10 based products, GE SMART (CEBus), and a "hard-wired" low voltage solution from a local company. We have only recently become a dealer for GE SMART (in the last year) because we felt it necessary to add another product line to our offerings that can be used in the retrofit market. We needed a product line that offered a higher level of security, repeatability, and elegance. GE SMART's CEBus system seemed to offer all that and more. Though we have been working through some isses with our GE SMART products, we are not disappointed with the product.

I actually have both systems installed in my personal residence of 3,200 s.f. Here are my candid observations of the two systems.

X10:

X10 is a great product with a great price, especially if your home was not pre-wired for automation. Though the technology is somewhat dated, it is proven and works extremely well so long as you know how to effectively "tune" the system and do not hang to many "offending", signal reducing, or noisy appliances on the system.

X10 is supported by many companies and has many excellent controllers available. Getting X10 product is easy because everyone sells it. Sometimes you have to be careful not go to cheap as you may be buying discontinued product that had known problems.

X10 in my home consists of 14 light switches (mostly dimmer), some appliances modules, one Hawkeye motion detector, a CM11A, a Transceiver, and an out-of-production Honeywell Home Control security system. The Honeywell Home Control system pretty much runs the house as I have found it to be a very reliable security system as well as an effective automation controller. The best part about the system is that the remote controls are coded only for my controller, making the X10 system more secure versus the commonly available universal remotes (which also have marginal range).

My system controls the majority of my lights and it does it reasonably well. The CM11A controls the motion sequence for the one Hawkeye too. It works well enough but it can get confused infrequently as signals get lost or propagate incorrectly. This causes inconsistencies in my pathway lighting. It is not a major problem, just a weakness inherent to X10 and its slow speed of execution.

The X10 controlled lights also flash when the alarm system trips. This feature is easily achieved with the Honeywell Controller (now ITI).  This is a very nice feature for helping emergency vehicles in finding the home.

CEBus:

CEBus is pricier than X10's low priced modules and switches but when you compare it to higher end Leviton or SwitchLinc, it become very comparable. Most people don't know this and automatically assume that since it is a new technology it must be more expensive. Let me go on the record to say that it is, in fact, comparable as a complete system.  However, at the present time, it is more difficult to purchase CEBus products as they are only available through (in the case of GE SMART) a hand selected dealer network.

CEBus benefits from a faster communications protocol, error correction, digital spread spectrum, and best of all, real two-way communication. The system is inherently more immune to noise generated from many appliances, especially fluorescent lights which can reek havoc on X10 installations. However, it shares the same "signal degradation" problem with X10. In other words, some appliances can attenuate the signal and these devices must be filtered or tuned with the system (filter modules) to regain effective system performance.

I have only two CEBus switches currently installed in my home but I also have a pretty elaborate demonstration box full of GE SMART products plugged into the house as well. So basically I have about 8 GE SMART modules in my home in various locations.

The first thing you immediately notice about the GE SMART switches is that they are extremely high quality, both inside and out. The have an upscale look and excellent, tactile feel.  The relay module, which can switch a 15A load, is quieter than any similar product I have used.  There are no awful "cluck" noises when activated, just a subtle click.  People who know nothing about home automation see these switches and are immediately impressed and quickly understand how to use these devices. My experience in high volume electronics manufacturing also supports my observations regarding the inherent quality of these switches. The solder joint quality, those connections that hold the individual electronic components to the circuit board, is superior to that of most X10 based modules I have disassembled. In fact, GE SMART is so proud to show off their printed circuit board that the entire assembly is boldly encased in clear plastic. If you know what you are looking for, you can inspect the quality yourself.

To reiterate, the GE SMART switches have very good tactile feel and impress me more than high end X10 based switches.  The GE SMART switches look very upscale and coordinate well next to you existing Decora switches. They also come in a wide variety of designer colors.  They look right at home in a $500,000 home!

GE SMART switches can be utilized peer to peer. In other words, they can be programmed to communicate to one another, without the need for an external controller. This does not allow timed events or motion sense, but it does allow one to create some basic level of home control such as ALL Lights ON or OFF (from scene buttons), and very simply I might add. Creating 3, 4, 5, way switches where none existed before is a snap.  I find that most installations rarely need or desire more functionality that this.

GE SMART's system gets more complex when you start to program it. At the present time, this is best left for the dealer/installer as the software that loads the controller is not as intuitive as many X10 software packages I have used. I think some of the offerings that control X10 still have GE SMART beat in this category. Though I have seen GE SMART's new PC Based application and I believe they will soon establish a new standard for the most effective user interface.

Where GE SMART really shines is with their interface control called the SMARTONE 8-4-8 Bridge. The Bridge is your CEBus interface to all products not created by GE SMART (and a few that are sold be GE SMART). It is similar to other X10 based, relay I//O control boards but it simply operates faster and more reliably.  It also offers more I/O in my experience.  What I really like about this device is that it can run independent of the controller as the control software can be downloaded directly into it. You can connect high quality motion detectors, alarm contacts, thermal and photo sensor, inductive sensors, etc. with ease. I have found pathway lighting with GE Smart to be 100% repeatable! Try running 4 motion detectors simultaneously on an X10 based system. What a mess that would be. The Bridge has plenty of horsepower to perform many tasks.

Also, GE SMART's switches are serialized and can access 1 of several thousand house codes. This means no more removing switch plates to set a limited number of unit or house codes as in X10. Re-programming on the fly is a breeze. Because there are literally thousands of house codes and each switch is uniquely serialized, two CEBus homes can live very peacefully side-by-side. There will be no cross talk between the homes. Try that with an X10 based system across two homes sharing the same transformer. 

Drawbacks to Both?

Yes.  As with any technical product, there are drawbacks to both systems and that is why HomeTek, Inc. will continue to offer both solutions to its customers. First and foremost, the two systems DO NOT live well together and according to GE SMART, they should not be used together. I have read many Usenet discussion where the authors have stated that both technologies can exist together, in the same home.  I doubt these authors ever tried them together.  If you want reliable operation, do not use both systems in the same home.  When the CEBus system is active, I frequently get all of my X10 modules to turn on. It is like someone hit an ALL LIGHTS ON command. X10 is very flaky when CEBus is on-line and becomes extremely unresponsive.  Why does this occur?  I believe, though I have not technically evaluated this yet, this occurs because CEBus (with its spread spectrum signal) can send a signal that sometimes resembles an X10 command.  That overlap can exist.

The CEBus system, on the other hand, is attenuated by the X10 system and products, especially by the CM11A and Powerflash modules. Unplug those items and disconnect the switch loads from the X10 system dimmers and the CEbus system becomes rock solid and 100% signal transmission is regained. Both systems can be disrupted via line attenuation. In other words, if you plug some appliances into your electrical system in your home, the filtering electronics on the power supplies of these products causes signal loss. This signal loss means that some parts of the house will not communicate effectively or will do so intermittently. Both systems require tuning. CEBus gets the edge because its spread spectrum signal seems to be extremely immune to electrical noise.

My Opinion:

As an installer of automation systems, keeping call-backs to a minimum is a critical part of my business, especially as my client base grows.  As a user of automation products in my own home, I personally desire a robust system. 

In my opinion, X10 is well suited for smaller residential application of say 3,500 s.f. or less where the customer is not 100% concerned about having the most reliable system. We recently installed an X10 based system in a 2,400 s.f. home of a man afflicted with MS. It was a perfect application of X10 based products.  He loves the system!  He uses it every day for controlling his lights and some appliances.  He has total remote control right from his wheel chair. X10 serves its purpose very well for these non-critical applications. However, he recently requested a system controlled lock on his front door.

Would I use X10 for controlling his door locks? Absolutely not. The security is not there and the reliability is not high enough. He cannot afford to have the door unlock due to a false signal nor can he be locked out of his house due to an X10 signal propagation problem. This door lock is a better application for CEBus or another system.

CEBus is clearly well suited for larger homes. In fact, we are designing a CEBus system for use in a home that is 22,000 s.f. in size. Since this home has banks of fluorescent lights in the basement, I would not even think of installing an X10 based system. There would be too much line noise.  Additionally, an X10 system would have required multiple amp/repeaters that can sometimes cause collisions amongst themselves.  The CEBus system will require the use of couplers in each breaker panel.

This large home also has more than 100 switches on the system with multiple motion sensors and automated dimming. Using an X10 system for such a complex job, with so many things occurring at once, would simply overburden the slow communications protocol of X10 and the associated controllers. Signals would collide and become lost as two or more motion detectors trip at the same time. This would be unacceptable and the reliability problem would be obvious to the customer.

So, in conclusion, my business will continue to install both X10 and CEBus products. X10 will continue to be a viable solution where cost is an issue. It will also be used where 100% reliability is not mandatory nor is two-way status really needed. It is still the value leader though I believe it could slowly lose this attribute to products like GE SMART as their volumes increase.

GE SMART's CEBus, on the other hand, will find its way into larger homes and possibly even light commercial buildings. Its two way status is necessary in larger complexes where the user requires the knowledge that a set of lights or appliances actually turned off when commanded to do so. It will also continue to be used in applications where many fluorescent and other noisy light sources are used. Basically, CEBus will be installed when I need to approach hardwired system reliability and performance and am limited by my ability to run low voltage wires, etc.

So what is the answer to the million dollar question…is CEBus better than X10? In a word, no. However, I have learned that it is not a question of which technology is really "better". It is more a question of which one is more appropriate for a specific application. To reiterate one last time, X10 is best suited where economy is necessary, reliability is not mandatory, and electrical noise is minimized and stable. X10 should be used where non-critical control is needed.

Use CEBus where two-way status is required, security applications are involved, reliability is more crucial, and electrical noise is more prevalent. For example, in a three story house with many lights in the basement, one would prefer a CEBus system to be able to verify that 10,000 watts of lights actually turned off and stayed off when commanded to do so.

I hope my experiences helped to shed some light on CEBus, as compared to the current standard, X10. Please feel free to visit HomeTek, Inc. at www.hometekinc.com for more details on CEBus products. Remember, we also install X10.  I welcome any relevant questions or experiences regarding these technologies as well.