Many devices are now equipped to use Power Over Ethernet (POE) as their power source. Such devices include VOIP telephones, iP cameras, wireless access points, and a growing variety of embedded devices. Fitlet, due to its miserly power requirements, is an ideal candidate for headless POE operation.
Some POE Basics
The most common forms of Power over Ethernet are specified by IEEE Standard 802.3. There are 2 prevalent variants of IEEE802.3 POE which are Type 1 Low Power covered by IEEE 802.3af (2003) and the newer Type 2 High Power covered by IEEE 802.3at (2009).
Any item of equipment used in POE applications can be classified as either Power Sourcing Equipment (PSE) or a Powered Device (PD). As their names imply, PSE's inject power into the systems and PDs use that power.
Some specfics about the POE variants are included in the table shown below.
- POE Data.jpg (132.64 KiB) Viewed 15627 times
The System
The Fitlet POE sysytem I tested is detailed in the following block diagram. Note that Fitlet is operating in a headless configuration and is controlled using VNC via a Compulab fitPC3 Pro running Windows 7.
For simplicity, I elected to run Fitlet in a headless configuration using a Compulab fit-Headless HDMI monitor adapter. This approach gives good headless results and does not require any changes to my Linux Mint OS.
- Fitlet POE Block Diagram.jpg (112.84 KiB) Viewed 15627 times