The Benefits of PoE for Industrial Applications
The drive for Power over Ethernet (PoE) started in the late 1990s. At first, Voice over IP needed power from a separate source. The simple dc power of Plain Old Telephone Service was missed. Early proprietary solutions for PoE gave way to standards-based ones, after IEEE 802.3af was finalized in 2003. The standard provides for 15 W at the source, at a nominal 48 Vdc. Key devices are power sourcing equipment (usually a PoE-enabled switch) at one end and a powered device at the other. This white paper discusses how PoE provides power and data over a single cable, simply and dependably.