issue: September 2003 APPLIANCE Magazine Electronic Controls and Embedded Systems A Smart Strategy	Share  Printable format  Email this Article  Search
by Lisa Bonnema, Managing Editor Smart appliance technology isn't anything new. At this point, many manufacturers have either released individual Internet appliances (i.e., Electrolux's Screenfridge) or a small line of communicating appliances (i.e., Salton Inc.'s White Westinghouse line).

However, most appliance OEMs have had a hard time committing to a specific networking technology, and very few have chosen to incorporate this advanced technology into the majority of a product line, fearing the average consumer isn't ready for it yet.

Even so, in a lofty effort to finally get this technology into the mass market, Samsung Electronics Company Ltd. has taken the next step. In June, the Korean manufacturer signed a Strategic Alliance Agreement under which Samsung will adopt Echelon Corporation's PL 3120 and PL 3150 Power Line Smart Transceivers and the LonWorks platform in its Home VITA home products line, which includes everything from refrigerators and microwaves to air-conditioners and televisions.

The new PL 3120 and PL 3150 Power Line Smart Transceivers from Echelon are based on the LonWorks platform, an ANSI standard for connecting everyday devices such as major appliances, thermostats, air-conditioners, and lighting systems to each other and to the Internet.

Michael Tennefoss, vice president of Product Marketing and Customer Services at Echelon (Sunnyvale, CA, U.S.), says this is a breakthrough announcement. "Echelon has been working with appliance OEMs for many years. Some have kept their projects in stealth mode, and some earlier adopters, like Merloni, have released systems," he says. "What is unique about Samsung is the scope of the project, both in terms of the number products and the number of different applications. The HomeVITA concept includes entertainment, data, appliances, and home control devices, and there is simply nothing else like it in terms of its scope."

Andrew Chon, Samsung Electronics' executive vice president and Digital Solution Center manager agrees: "When people look back at 2003, they will see it as the pivotal year for the home networking market and the relationshipÆ’between Samsung and Echelon as the catalyst that moved the market into mainstream, high-volume adoption."

Echelon's relationship with Samsung started more than 2 years ago, when Samsung decided to test its networked appliance concept.

"Before Samsung entered into this strategic alliance, they completed extensive tests and fielded many systems to ensure that the concept worked both in concept and in real homes," Mr. Tennefoss explains. "Samsung is a very fast-moving company once when they have made a decision to move forward, but they're very conservative with regard to their up-front engineering assessments. In my experience, Samsung only ships products that have been rigorously and thoroughly tested."

Part of the testing process included what Samsung refers to as its Tower 1 and Tower 2 projects, which involved incorporating its Home VITA line with Echelon networking technology into some apartment buildings in Seoul.

After extensive testing, Samsung found that the key to igniting the home networking market is to make the networks completely invisible and totally reliable„a challenge it believes Echelon's power line technology can meet.

"Our years of experience with Echelon's power line technology has proved to us that rock-solid, plug-and-play networks of appliances, air-conditioners, consumer electronics, and home control devices are not only cost-effective to build, but simple for consumers to install," says Mr. Chon.

Power Line Performance

One of most innovative aspects of the partnership is the use of Echelon Corporation's PL 3120 and PL 3150 Power Line Smart Transceivers, which were released in February of this year.

Originally, Samsung was using Echelon's PL22 power line system combined with a neuron chip. Together, these two components provided functionality that is now available on the power line smart transceiver.

"The power line smart transceiver is the result of a cost reduction effort in which those two components were merged together into a common integrated circuit. It was quite an engineering task to combine such complex elements into one low-cost integrated part," Mr. Tennefoss explains.

As with all LonWorks devices, the new transceivers are designed with three Echelon-developed microprocessors, a crucial aspect to the technology's reliability, Mr. Tennefoss says. "A standard microprocessor contains a single processor. If that microprocessor is used for a control application, then it has to simultaneously run applications, monitor sensors and control actuators, and manage incoming and outgoing network messages. A standard microprocessor is not optimized for such an application and as a result, delays or causes errors when inputs, outputs, and messages need to be handled simultaneously," Mr. Tennefoss says.

"When we designed LonWorks technology, the design target was to support simultaneous processing of application programs, sensor inputs, actuator outputs, and network messages," he adds.

For example, in smaller applications like a light switch or a carbon monoxide detector, one of the smart transceiver's microprocessors would run the application that's monitoring and processing the product I/Os, and the other two would manage the network communications. However, in more complex applications such as a dishwasher or washing machine that already comprise multiple microprocessors, Mr. Tennefoss says the manufacturer will often take a different approach. "Network communications will still be managed by two of the smart transceiver's microprocessors, but the third processor will use our ShortStack software to interface with the machine's existing microprocessors. ShortStack allows a product manufacturer to use all of its existing, proven software applications and processor architecture, and converts the smart transceiver into a communication 'front end' for the machine," he explains.

One of the keys to reliable power line signaling, notes Mr. Tennefoss, is the use of digital signal processing. "We use very sophisticated algorithms within the transceiver to overcome typical impediments to power line signaling," he notes. "These impediments, such as electrical noise, tend to be huge relative to the power line communication signal. Think of the power line signal as being a boat, and noise as being an iceberg„both in terms of its relative size and as a hazard to navigation. Digital signal processing provides the navigation information that we use to successfully sail the boat through the iceberg field without any errors."

The power line transceiver also uses error correction to deal with malformed packets or messages that have been affected along the way.

Another feature is dual-channel signaling, which means the transceiver can transmit at two different frequencies to overcome power line impediments. "The smart transceiver transmits first on the primary channel, using the highest possible speed signaling and good error correction. If the packet cannot get through the first time, we transmit on the back-up, or secondary, channel, at slightly lower speed but with extremely robust error correction. Dual-channel signaling allows the signal to be reliably received and results in extremely robust performance in the face of severe noise sources," Mr. Tennefoss says.

The two frequencies also reportedly allow an appliance maker to design a communication board or communication system that can be sold in any country their products are sold. "Our power line products have been designed, tested, and certified for use in applications worldwide," says Mr. Tennefoss. "The same product that sold into the U.S. can comply with the very stringent European signaling standards, as well as the very stringent, but different, Japanese signaling standards."

Another critical component is a high-performance amplifier. "The impedance of the power mains, especially with high-current appliances, can vary widely," notes Mr. Tennefoss. "When motors turn on or off or heavy currents are drawn, the impedance of the power mains can drop to almost a dead short from a signaling perspective. To overcome this, we have designed a special amplifier that's capable of delivering a high current signal over a very wide impedance range."

More for Less

The most difficult task in designing the smart transceivers, according to Mr. Tennefoss, was offering a more sophisticated technology at a lower price point and in a smaller package. "The power line smart transceiver is designed with 0.18-micron line width, which is approaching state of the art in terms of standard manufacturing processes incorporating non-volatile memory. We worked together with our manufacturing source, STMicroelectronics, to fit our sophisticated power line modem, three microprocessors, flash memory, RAM, and ROM into an extremely small silicon die size."

The end result is a fully loaded transceiver that is about the size of an eraser head on a standard yellow pencil. In addition to the microprocessors, modem, and memory, the small package also includes the amplifier, although it requires two external power transistor drivers.

And while Mr. Tennefoss recognizes that cost is a very important consideration for appliance makers, he notes that reliability and consumer acceptance should be an OEM's main focus. "Appliance makers cannot afford high warranty costs since they already operate on thin margins. Rolling a service truck to investigate a communication problem would greatly diminish a manufacturer's profits and must be avoided. That's why it's of paramount importance that any connected appliance have robust, dependable signaling performance of the level offered by our smart transceiver," he says.

"Adding intelligence to an appliance also adds cost, and a manufacturer will only add cost when there is a compelling, competitive advantage to do so," Mr. Tennefoss continues. "Over the past couple of years, Samsung has been investigating how to best achieve such competitive positioning, and what benefits will accrue to the consumer. The result in the Home VITA product concept."