Industrial versions of Ethernet offer more rugged hardware, industrial protocols and real-time TCP/IP extensions. The question of whether Ethernet will penetrate down to the field level has become closely linked with real-time issues, plus service, calibration and diagnostic messaging within the device itself.
In industrial automation, the old Fieldbus wars have given way to the dissemination of several competing standards based on physical distance, speed of operation, real-time capabilities and other application-specific requirements. In the quest to attract wider usage and interoperability, most proprietary networks have become “open” standards.
Most suppliers profess to support all major industrial networks to provide the device interoperability that end-users expect. But some skirmishes continue—for example, the battle between EDDL and FDT/DTM solutions for manufacturer-independent integration of field devices. In my opinion, the objections are not related to technical performance, but are primarily commercial—coming from leaders who want to retain their advantages rather than diffuse them by allowing competitors to participate through a technical “back door.”
Wireless sensor networks
These battles pale into insignificance when one considers what’s on the horizon—the next big inflection point. Just as the Internet allows access to digital information anywhere, wireless sensor networks will provide vast arrays of real-time, remote interaction with the physical world. The industrial automation business will be generating significant growth in this new arena.
Wireless connectivity is already widespread in office and consumer environments, and industrial automation is moving quickly to take advantage of the overwhelming benefits. A bewildering variety of technology choices are available.
Wi-Fi (IEEE 802.11) is common with laptop computers and can be used for PDAs (personal digital assistants) and personnel equivalents in industrial applications. Operating range is limited to a few hundred feet, or less, depending on obstacles. For a typical factory or process plant, repeaters or extenders may be required to facilitate reliable reception throughout the operating environment. Wi-Fi has fast throughput and bandwidth of 10 megahertz or more, but consumes resources (memory, battery life) which typically limit applications to portable equipment that can be recharged often.
While Wi-Fi is merely a wireless version of a broadband extension cord with a short range, WiMax provides high-throughput broadband connections over longer distances. Several industrial product developers are offering WiMax for factory and process plant operations.
Bluetooth, named by the original Scandinavian developers after a Viking chieftain, uses fewer resources and less power than Wi-Fi, but has a transmission range of only about 20 to 30 feet. It is best suited for elimination of cables between line-powered equipment and close-by extensions (e.g. printers). In factory and process plants, it is typically used to connect control-room devices.
For connecting large numbers of input/output points in factory or process installations, ZigBee networks are quickly coming to the fore. Built on top of the IEEE 802.15.4 standard, ZigBee uses license-exempt communications frequencies. The significant advantages are very low power, minimal resource requirements, transmission range of up to a few hundred feet, adequate bandwidth for industrial applications, unlimited network size, high reliability and low cost. Look for ZigBee to generate significant growth in a variety of industrial applications.
Wired and wireless connectivity will eventually reach tens of billions of connections, adding significant value for industrial suppliers and end-users alike. The term “Pervasive Internet” refers to the convergence of machine-to-machine (M2M) communications, wireless sensor connectivity, enterprise-level data-management applications and Web-based smart services. The phenomenon is already emerging, and the implications are nothing short of revolutionary. Companies and products that fail to exploit this next wave of the digital revolution will simply obsolete themselves.
Jim Pinto is an industry analyst and commentator, writer, technology entrepreneur, investor and futurist. You can email him at: firstname.lastname@example.org. Read extracts from his new book, “Pinto’s Points” at: www.jimpinto.com/writings/points.html