IEEE updates network standards to aid Ethernet, low-power devices

Staff -- Control Engineering, 8/1/2003

Piscataway, NJ — End-users and vendors of industrial Ethernet equipment are gaining more flexibility in assigning Ethernet-type numbers and receiving guidance on supplying power to low-power data terminal equipment with local area network (LAN) connectivity. Changes came when the Institute of Electrical and Electronics Engineers Standards Association (IEEE-SA) Standards Board approved on July 11 two amendments to its IEEE 802 wired network standards. IEEE 802a allows vendors to assign Ethernet Type numbers without depleting the number space, and IEEE 802.3af addresses the power topic.

IEEE 802a, also known as "Ethertypes for Prototype and Vendor-Specific Protocol Development," gives vendors a small number of Ethernet Type values they can assign as protocol identifiers for prototype and experimental use. Until now, vendors applied for values from the limited Ethernet Type number space for both development and the final protocols. This led to wasted numbers. IEEE 802a allows for prototype and experimental protocols without consuming type values and for permanent protocol identifier values to be assigned without consuming type values.

IEEE 802.3af, also known as "Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications—Data Terminal Equipment (DTE) Power Via Media Dependent Interface (MDI)," defines how to feed power over balanced cabling to data terminal equipment having IEEE 802.3 interfaces. The power level is limited by cabling physics and regulatory considerations. The standard specifically addresses a new class of low-power devices with IEEE 802.3 LAN connectivity. These projects were sponsored by the IEEE Computer Society.

IEEE Standards Association develops consensus standards through an open process that unites diverse parts of an industry. These standards set specifications and procedures to ensure that products and services are fit for their purpose and perform as intended. IEEE-SA has a portfolio of more than 870 completed standards and more than 400 standards in development. More than 15,000 IEEE members worldwide belong to IEEE-SA and voluntarily participate in standards activities.

For more information, visit http://standards.ieee.org or www.ieee.org .