Network advice: More power over Ethernet offers design flexibility
Those implementing industrial networks should plan ahead for higher power capabilities over Ethernet (from 12.95 W to up to 60 W per device), suggests Venture Development Corp .
Commenting on Ethernet's expansion in power conversion and control practices, Venture Development Corp. (VDC) offers a research note on Power Over Ethernet, The PoE+ Standard and New Opportunities . VDC's Brian Greenberg, analyst for power conversion, says, "With the past success of Power over Ethernet (PoE) (IEEE standard 802.3af) powering network devices operating on 12.95 W or less, observers expect great things from PoE+ (IEEE-pending standard 802.3at). 802.3at is expected be able to provide 30-60 W to a single powered device (PD)."
Greenberg says PoE has helped reduce the cost and complexity of installing devices on an IT network, including VoIP (voice over Internet Protocol), WLANs (wide local area networks), and certain security camera applications. The use and need for PoE is apparent in a number of applications. VDC's study Power over Ethernet: Global Market Opportunity Analysis, Second Edition predicts that vendors will ship more than 21 million VoIP ports and nearly 5 million WLAN ports per year by 2008.
Additional power of PoE+ may drive new applications without need to run a conduit for ac power. Emergence of PoE+ will enable greater functionality for existing PoE applications (with backward and forward capabilities), Greenberg suggests, and will make enough power available to drive new applications without dedicated power, including monitoring cameras, more sensors, transmitters, and wireless devices, as well as thin-client workstations. Separately, Control Engineering has heard from enclosure manufacturers recommending that automation designers plan ahead for additional power and heat in what previously may have been uncooled, unventilated network boxes or communications closets.
For more information about VDC's "Power Over Ethernet: Global Market Opportunity Analysis, 2nd Edition," or for more on this research note in PDF form, click here .
Also search on PoE www.controleng.com for more guidance on this topic and read " Power over Ethernet becoming standard in many products ."
—Edited by Mark T. Hoske, Control Engineering editor in chief