Homeowners want wiring that will link them to the Web and support other electronic toys. Part Two of two parts.
In Part 1 of this article in last month's issue (page 30), readers learned a little history about the development of the structured-wiring market. This article explores the technical standards that dictate which products are used in these systems.
THE IEEE 1394 STANDARD Some industry groups cooperated in developing the IEEE-1394-1995 standard, also called FireWire. First conceived by Apple Computer, FireWire allows information from broadcast, cable or satellite TV and the Web to be sent to a TV or other consumer electronic product.
FireWire uses a special shielded cable with six individual conductors: one for power, one for ground, two for data, and two for strobe, which synchronizes the data. Any single device (which is called a node) can be used to control all the others. Every device houses a transceiver, and all transceivers, connected together in a serial bus, must be turned on, or powered, all the time.
The IEEE 1394 standard was developed to interconnect audio-visual equipment over short distances in a cluster or group, such as a home theater or home entertainment system. For whole-house applications, a trade organization called the Video Electronic Standards Association (VESA) has been working on a home-automation-oriented, high-speed data network based on one version of IEEE 1394, namely, IEEE 1394b.
The 1394b version (still a draft standard) is a long-distance variation of the IEEE 1394 standard that defines twisted-pair and fiber (no coax) for 100, 200, 400 and 800 Mb/sec transfers over distances up to 100 meters. While primarily intended for A/V applications, the VESA spec can be used for anything - computer networks, home automation, etc. It's about the closest thing there is to a high-speed whole house network.
CONTROL NETWORKS Control networks require very low speed transmission - not much over 10kbits/s - and several companies have reliable schemes to transmit such data rates over a home's AC wiring. The two most important control technologies are the Consumer Electronics Bus (CEBus) and Lon Works, since both use a peer-to-peer architecture and rely on relatively simple network protocols that work with microcontrollers.
The EIA-600 CEBus Standard for Consumer Electronic Bus, developed by the Electronic Industries Alliance (EIA) provides a communications and control network. This standard allows for a variety of media types to be used: twisted-pair, coaxial, and fiber-optic cable, powerline carrier, infrared devices and radio-frequency (RF) transmission. It's intended for such functions as remote control, status indication, energy management, entertainment device coordination, and distribution of audio and video.
ANSI/EIA-709 covers the other major contender, the LonWorks standard, which defines a common protocol and transceivers that operate over AC power lines using narrow-band signaling and free topology twisted-pair Category 5 media. It also covers other media.
The first powerline carrier technology for the home was the X-10 system. Wall switches and receptacles containing X-10 technology were simple enough for consumers to set up the control systems themselves. Unfortunately, the reliability of X-10's simple protocol varies significantly among installations. To improve reliability, X-10 has made many refinements over the years and has retained its simple modulation scheme and generally has kept new units compatible with older products. Unlike CEBus and LonWorks, X-10 is not an ANSI standard, and therefore is not considered an "open" standard.
COMPLETING THE PICTURE Think of the 570-A standard as the physical layer platform that can serve all of the low-voltage applications in a residence. These include voice (telephone, computer modem and fax); video (baseband for surveillance and broadband for cable-TV or satellite); data (a LAN to interconnect computers and printers); alarm and security devices (dial-out for fire and burglar alarms); and home automation control of HVAC and lighting.
You can then connect EIA-600 compliant home-automation devices into the structured cabling system as needed. Finally, home theater/entertainment equipment can be interconnected using IEEE 1394-compliant patch cords with plug-and-play use.
Home automation systems may not yet be big business in your market area. But it's pretty obvious that market demand for these products will grow quickly in the future because of consumer interest in high-speed Web connections, computer networking, and state-of-the-art security and dimming systems. Chat with your customers - as well as builders - in your market area to get a feel for where this market may be headed. The channels of supply in this niche are probably not yet established, and you may have an early opportunity to become the preferred source of supply for structured wiring and related products.