Renesas Electronics

EDGE

The PLC (Power Line Communication) standard is set to enter widespread use. The standard can be used to construct a network using existing power cabling and can control equipment within the home via power sockets. Thanks to a partnership formed with ITRAN Corporation, Renesas already integrates PLC functions into the microcomputers in our H8S and M16C families. The special-purpose M16C/6S microcomputer, which has a built-in high-reliability PLC circuit, is one of our solutions that will help make PLC home networks a widespread reality.

Making home life more comfortable and safe, while saving energy

A home network makes possible the networked control of appliances, HVAC equipment, security systems, and other devices. The network can be accessed via the Internet to turn on air conditioning and start heating a bath, or to turn off lights and check the door and window locks. Such functions make life more comfortable and safe. Other automatic control functions that use various sensors are expected to generate considerable energy savings, too.

Controlling home appliances and similar equipment only requires a very small bandwidth. The volume of data consists mainly of on/off information, unlike the large volumes of data used in entertainment systems. On the other hand, control application implementations must be highly reliable to ensure accurate, dependable control.

At Renesas, we define "in-home narrowband networks" as networks with a bandwidth of 5Mbps or less. Within that category, we define "in-home control networks" as those that operate with speeds of up to 100kbps and are commonly used in control applications (figure 1).

Two main technologies appear to be most promising for implementing in-home control networks. Wireless technology such as ZigBee is one potential infrastructure. Most attention, though, is centered on PLC (Power Line Communication), the technology that is the closest to practical applications.

PLC is a power-line network that uses the 100V ac power cables in a house as its communication medium. It works by injecting a signal onto the electrical wiring that extends throughout a home. Existing power sockets and cabling can be used, so PLC represents a genuine "no new wire" solution.

Renesas got involved with PLC from an early stage and we have accumulated extensive experience with the technology. For example, an automatic metering system now installed in Italy consists of more than 26 million PLC devices based on H8S microcomputers. Nevertheless, the market for using PLC in the home has yet to take off. Obstacles to market acceptance and growth include the difficulty of ensuring reliability; concerns about the use of power cables, with their high levels of electrical noise, as a communication medium; and the fact that no de facto PLC standard has yet emerged.

Device Development for Control Solutions
To spur the growth of control applications for home networks, Renesas supports the technologies that deliver reliable performance and are closest to being practical.

IT800 technology from ITRAN eliminates concerns about connection reliability

A goal of ITRAN Corporation (ITRAN) is to eliminate those obstacles. This Israeli company’s IT800 technology for PLC modems opens up new possibilities for applying PLC in the home because it delivers a higher level of reliability than previously achieved.

To improve control-network reliability, IT800 technology combines a number of measures. It uses DCSK (Differential Code Shift Keying), which is an extended form of spread-spectrum communications, and CRC16-based error correction. Also, it can switch between three speeds (7.5, 5.0, and 1.25kbps) to optimize communications for the existing line conditions. The result is a high level of tolerance for impediments such as signal attenuation, noise, and phase and frequency distortion.

The communication scheme ITRAN uses is permitted under the current radio law and recognized by bodies such as ARIB (Association of Radio Industries and Businesses) in Japan, the FCC in the USA, and CENELEC in the EU. This makes it a viable solution for global markets.

Recognizing the value of this technology, Renesas was quick to begin investigating how to incorporate it into our microcomputers. One development is the "UltraPLC" PLC module (developed by Hitachi ULSI Systems), which is based on IT800 technology and a series of proprietary protocols. We use this module in an H8S device and in the M16C/6S, a special-purpose, single-chip PLC solution in the M16C family.

The M16C/6S microcomputer combines the M16C/62P CPU core with ITRAN Corporation's latest IT800 PLC modem and an analog I/O front end. The device supports the SCP (Simple Control Protocol) communication technique proposed by Microsoft for use in home networks and has a high level of compatibility with the emerging UPnP standard. In the future, we expect that the device will support the ECHONET standard now being formulated in Japan.

To help customers design systems based on the M16C/6S device, we have developed products that combine to provide a fully featured development environment for it (figure 2). Those Renesas products include the EVB4 dedicated PLC module evaluation board, an application board, and an adapter board for software development.

To highlight the capabilities of PLC and SCP technologies, we have successfully demonstrated that home appliances in an overseas showroom can be controlled via the Internet. Photograph 1 shows the screen of an Internet-linked mobile phone in Japan that was used to operate equipment in an SCP-PLC showroom provided in the USA by RAMP Corporation.

Controlling the Intensity of Light Bulbs
The photograph on the right shows a demonstration version of a PLC module for light fixtures that is based on the M16C/6S microcomputer, which incorporates ITRAN Corporation's IT800 technology. The diagram shows a set of two units. The intensity of two lights can be adjusted together simply by plugging them into the ac power. Both the switch and lighting control functions are implemented on a single PLC unit using the SCP property router function.

This screen on a mobile phone in Japan was used to control home appliances in an SCP-PLC showroom in the U.S.

Needed: services that assist users by operating PLC applications remotely via the Internet

The success of PLC as a driver of the home network market depends on more than the development of various PLC-based applications. A social infrastructure must be established for the ongoing use of the technology. The advantage of requiring no new wire in a home will be diminished if each household has to implement and operate these applications on their own. For this reason, not only is Renesas enabling customers to develop products with PLC functions, we also plan to establish partnerships with service providers so that backup will be available for operating the applications from outside the home via the Internet.

Growth in PLC systems today is inhibited by initial setup costs. However, we expect that growth will be greatly accelerated if service providers can offer key management, fault diagnosis, maintenance, etc. via centers that operate 24 hours a day. As such services grow, it is highly likely that self-diagnostic functions will be added. In turn, this will allow manufacturers of PLC-enabled devices to monitor the status of their devices via the network when a fault occurs or when periodic maintenance is due. Another possibility is the establishment of business models based on linking equipment usage to billing systems.

Having implemented the IT800 technology at a practical level in our semiconductors, Renesas now aims to establish the M16C/6S microcomputer as the de facto standard for PLC solutions in home control systems. This device will encourage the early development of PLC equipment by customers and increase the spread of the PLC technology and applications.

Growing range of control solutions

Renesas offers solutions for home network systems that use other communication protocols besides PLC. For example, we can combine the middleware associated with ECHONET and Bluetooth with our Tiny series of microcomputers (figure 3). Other control solutions in our extensive range include the H8/38004 microcomputer with ZigBee capability and temperature sensors that use the H8/38086 device.

We see a very bright future for home network applications. Powered by Renesas solutions, they will far extend beyond the entertainment, communication, and control categories and will prove useful in many other ways. For instance, society would benefit from the appearance of health management services that poll measurement devices such as blood sugar meters in patients’ homes, collect medical data remotely, then send it to labs or medical centers for analysis and diagnosis. Also, home owners would benefit if security services could monitor intrusion sensors on keys, windows and doors, then send an alert via a mobile phone when problems occur while the owners are away from the residence.

One key factor that will determine the viability of these and other applications will be the availability of encryption algorithms and other techniques that prevent critical information from being misappropriated or falsified. Renesas encourages and supports the development of the necessary security safeguards.

Home Network System Using “Tiny” Series Microcomputers
The elements of this home system built with Renesas microcomputers use PLC and other network technologies to control appliances.

Offering technology for networking equipment in buildings and homes that enables control via the Internet

Matsushita Electric Works


	Masaichi Fukunaga General Manager Building Systems Development Center Matsushita Electric Works,Ltd.
	Yoshiyuki Komoda General Manager Systems Technology Research Laboratory Matsushita Electric Works,Ltd.

Matsushita Electric Works manufactures equipment for buildings and homes and is a top supplier of network solutions for those markets. To help realize a society of ubiquitous networks, the company promotes a multi-platform, multi-vendor, and multi-protocol philosophy. The core technologies required to achieve this are the EMIT (Embedded Micro Internetworking Technology) MICRO HOMEPAGE technology it has developed independently, as well as IPv6 and sensor networking technology.

Mr. Fukunaga, who manages building systems development, explains that "by applying EMIT in BAS (building automation system) applications, various equipment in a building such as air conditioning, lighting, power, and sensors can connect to the Internet to allow real-time monitoring, despite their different protocols." The company already operates a prototype of its "EMIT Total Building System" in its own building. The system, which uses EMIT as the core technology for its network, is still at the experimental stage, yet it has achieved annual energy savings of a startling 29.4 percent.

EMIT is applicable not only in commercial buildings, but also in homes and apartments. As Mr. Komoda, who is responsible for home networking, explains, "We can control the status of electrical equipment such as TV door-phones, electrical locks, lighting, and air conditioning from a PC or mobile phone via the Internet." To meet the needs of home owners, Matsushita Electric Works now offers the "EMIT Home System" and "EMIT Mansion System."

This distribution box for the EMIT Home System incorporates an SH-3 based home gateway that exchanges data with a center server via the Internet (home LAN unit, Naplinet system support).

The Naplinet system interface unit (left) controls equipment in the home via power-line communications, while the Naplinet system switch (with internal relay) controls the lighting. Both devices use H8 family microcomputers.

Equipment, particularly lighting, is connected in an open network by this compact gateway, which uses an SH-3 series 32-bit microprocessor.

An H8 series microcomputer is used in this induction lamp that has an EMIT communication function and a self-test function for the lamp and battery, etc.

Compact code can run on 8-bit microprocessors

An EMIT system is typically made up of various devices that support communications, a gateway (including types that incorporate control functions), and general-purpose network devices such as PCs or mobile phones. The software running on the devices is sufficiently compact (2 to 3KBytes) to run successfully on 8-bit microprocessors. However, the software on the gateway requires multi-protocol functions and support for security.

Matsushita Electric Works has been using Renesas microprocessors for more than 20 years, and we were involved with the development of EMIT from the design stage. "Renesas engineers were very helpful, says Mr. Komoda. "For example, they added the functions we required to their microprocessors."

In commercial applications, the gateways for the equipment in buildings require a high level of processing performance, including network support and a web server. Therefore, they are based on SuperH RISC devices. In contrast, the processing requirements needed in the equipment being controlled are much lower, so economical H8 microcomputers are used, which helps keep the total system cost low.

In home system applications, an SH-3 series processor is used in the gateway, which also acts as the IP terminal. Other parts of the system are based on various microcomputers from the M16C family, H8 family, and H8/Tiny series, whichever device best suits the task being performed.

Generally, equipment used in homes and buildings has a lengthy warranty period, much longer than office equipment, for instance. Equipment is only replaced gradually and is expected to remain in operation for many years with periodic inspection and maintenance. This issue was addressed by the engineers at Matsushita Electric Works. As Mr. Fukunaga explains, "Once a microprocessor has been selected, it remains in use for a long time, so we are concerned that the microprocessor series might be discontinued. This does not happen in the case of Renesas microprocessors. The fact that Renesas continues to keep the same architectures in their product range is very reassuring."

Looking forward, Renesas will continue to provide solutions that deliver a high level of added value and confidence for customers that produce networking applications for controlling building and home equipment.

Providing early support for communication protocols by building on technical strengths gained in commercial applications

Daikin Industries


	Takashige Kai President Daikin Systems & Solutions Laboratory,Ltd.
	Tadashi Sakaguchi Senior Engineer Air Conditioning Manufacturing Division Product Development Group Daikin Industries,Ltd.

Daikin Industries Ltd. is the leading air-conditioning manufacturer in Japan. It supplies more than 40 percent of the commercial air conditioners sold in the domestic market and offers innovative high-performance home room air conditioners based on strong proprietary technology. The latter include the products in "The Ururu Humidifier " range, which can dehumidify without cooling or humidify without a water supply, and those in its Inverter C series, which, at only 15cm, are the thinnest such products on the market.

Daikin uses Renesas microprocessors in its commercial and home products. Devices in the M16C family and the SH-2 family implement inverter control in the outdoor units, while H8/Tiny series chips control of the indoor air conditioners.

Daikin was an early adopter of networking for the control functions handled by these microprocessors. The company already uses the telephone network and Internet for remote monitoring and maintenance of its commercial air conditioners.

The air-conditioning systems used in offices and other buildings can be thought of a network of numerous outdoor and indoor units. Those units, linked via proprietary communication and control protocols, form an environmental control network that carries control signals and sensor data. When this HVAC network is combined with the higher-level IP data network, the result is an advanced control network.

Applying technology from commercial systems to home applications

Much of the know-how Daikin has gained by controlling the air-conditioning equipment in multiple offices from a remote monitoring center can be utilized in the field of home networking. So, to capitalize on its HVAC network experience in commercial buildings, the company is exploring ways enter the home networking market. Daikin is said to be making rapid progress in evaluating and investigating the technology needed to implement functions such as temperature adjustment and on/off control of air conditioners via home networks.

As Mr. Kai of Daikin Systems & Solutions Laboratory Ltd. explains, "Looking from the customer's viewpoint, users will want to connect all of their electrical equipment to their home network, not just air conditioners. The first step, therefore, is to install in the home an open network that can connect to a wide range of different home appliances. What is important, then, is that the customer be able to get total solutions that utilize this network. In the case of an air conditioner, for example, the user must be able to control the operation of the unit to suit his or her preference by adjusting the temperature setting remotely."

To make such a scenario possible, a framework must be put in place that allows a flexible approach to product development, while maintaining a close watch on progress towards the standardization of home networks. Daikin has already incorporated an interface in its home air conditioners that permits remote control of their basic operation. The company has made many requests to Renesas to ensure that our microprocessors support home network standards.

The stylish and compact Inverter C series of energy-efficient air conditioners have a flat front panel and are the thinnest available, only 15cm thick.

Making progress on supporting many different communication protocols

Mr. Sakaguchi, who is responsible for product development at Daikin Industries, says, "Collaboration between different industries is a key to success in the home network sector. This does not just mean that a company must support many different communication protocols. It also means that the company must collaborate with semiconductor manufacturers such as Renesas that provide vital technology and have contact with many different manufacturers."

Clearly, the greatest possible number of people will be able to enjoy the benefits of home networking only if the networks can connect to equipment from all manufacturers. Daikin understands connectivity issues well, because in the commercial sector it regularly must consider how best to link its products with those of other manufacturers. This explains why the company pays close attention to trends in home network standards.

Daikin already works with Renesas on research into commercializing power line communication technology that is a focus of the ECHONET standard. Development of technology for utilizing PLC modules is now said to be largely complete. Daikin has also announced that it is working in parallel on other networking techniques such as wireless links. The company aims to give consumers confidence that it will produce products that can easily be connected to whatever form of communication becomes the standard for home networking.

top