Many different applications of Power over Ethernet, aka IEEE 802.3, or PoE as engineers like to call it, have been employed over the past 20 years, both standardized and proprietary. PoE transmits electric power along with data on twisted pair Ethernet cabling, enabling a single cable to provide both data connection and electric power to an array of devices including wireless access points, IP cameras, and VoIP phones.

PoE eliminates cables by directly applying power to a host of peripherals in commercial and industrial settings.

PoE was commonly referred to as “power injection” at its inception. These “power injectors” provided power, either AC or DC, on Ethernet cabling sans intelligent protocol or safety considerations. The most common methodology involved using the “spare” pairs not used by 100Base-TX Ethernet to inject power. This inspired the IEEE 802.3 Working Group, which defines and revises the standard commonly referred to as “Ethernet,” to begin devising a safe way to deploy PoE.

A host of ICs are now broadly available to drive PoE hardware. These include interface controllers that satisfy the increasing power requirements of IoT endpoints. PoE installments must comply with IEEE 802.3bt, IEEE 802.3af, and IEEE 802.3at, enabling up to 90 W of power, which also ensures interoperability between PoE devices. Compliant devices also include an auxiliary detection pin and support auto-classification features that enable equipment to delegate power to each powered device in the most efficient manner possible. 

As the standards move forward, with increased power options, the number of potential applications increases. Couple that with increased reliance on the IoT and the Cloud, and smart buildings and even smart cities can become realities. That opens the doors for applications like energy, automation, IIoT and transportation.

For diverse industrial applications such as energy management, PoE networks can control monitoring, sensing, and management for things like wind turbines and solar panels to manage the energy generation and voltage management. Other real possibilities include retail gas pump metering payments, along with oil and gas production. Potential automation applications include smart factories and manufacturing, agricultural automation, irrigation, and logistics and warehouse management. Intelligent transportation applications involve traffic control and safety systems, vehicle PCs, predictive diagnostics and preventive maintenance, video surveillance for safety, security and asset management, and public transportation systems for ticketing, and passenger control.

The WINSYSTEMS’ SBC35-C398Q quad-core single-board computer is designed for demanding graphical applications in security, transportation, medical, and digital signage.

WINSYSTEMS’ SBC35-C398Q and PPM-PS397-POE platforms are designed to operate in a PoE environment while having the ability to withstand the elements required by the desired industrial applications. The SBC35-C398Q features a Freescale quad-core i.MX 6Q Cortex A9 processor operating at 800 MHz; 2 Gbytes of DDR3 RAM that’s soldered directly onto the board; and high-performance video and graphics with multiple video interfaces. It can operate from -40°C to +85°C without the need for a fan. The PPM-PS397-POE includes isolated voltage outputs which provide up to 25 W of combined power to a PC104 stack, with line and load regulation at ±100 mV for all outputs, with no minimum load required for regulation.

The WINSYSTEMS’ NET-429 network switch is designed for the harsh environments of the factory floor and provides performance for time-critical industrial networks with Power-over-Ethernet (PoE) PD support.

Another system that peforms well in PoE applications is the WINSYSTEMS’ NET-429 network switch, which is designed for harsh factory floor environments. Providing the performance needed for for time-critical industrial networks, the switch has eight 10/100/1000 Mbit/s RJ45 Ethernet ports and two 1000Base-X SGMII SFP ports, as well as redundant power inputs with PoE PD support. Offering 10+ years of availability, the NET-429 offers fanless operation in temperatures ranging from -40°C to +85°C.

Considering PoEs’ history and present-day functionality, there will be more demand for additional power as the applications continue to broaden. Future standards will offer even higher power levels and more convenience for users and operators.