9.1 PoE [T-Series Datasheet]

Power over Ethernet (PoE)

Power over Ethernet (PoE) is a standardized technology that enables the transmission of both electrical power and data over a single standard Ethernet cable. This eliminates the need for separate power cables, simplifying installation and reducing cable clutter for compatible devices.

PoE Terminology

• PSE (Power Supplying Equipment): The device that provides power over the Ethernet cable (e.g.: PoE switches, routers, or injectors).

• PD (Powered Device): The device that receives power over the Ethernet cable (e.g. LabJack T8).

T-Series Device PoE Support

Some T-Series LabJack devices can operate as Powered Devices (PDs) using Power over Ethernet (PoE). Refer to the table below for specific PoE standard support for each device:

How PoE Works

For a PoE-enabled device (PD) to receive power, it must be connected to Power Supplying Equipment (PSE) via an Ethernet cable. The PSE, which can be a PoE-enabled network switch, router, or a standalone PoE injector, automatically detects the presence of a compatible PD. Once detected, the PSE will supply the appropriate amount of power to the PD.

PoE Standards (as of May 2025)

Currently, there are three primary PoE standards:

• PoE (IEEE 802.3af): The original standard.

• PoE+ (IEEE 802.3at): An enhanced standard capable of supplying more power than PoE.

• PoE++ (IEEE 802.3bt): The latest generation, offering the highest power delivery capabilities.

The newer PoE standards are backward compatible with older ones, ensuring that PoE+ PSE can power PoE PDs, and PoE++ PSE can power both PoE and PoE+ PDs.

Passive PoE

Passive delivery of power over an Ethernet cable is not standardized and carries several risks. LabJack devices do not support any sort of Passive PoE.

Further Information

For more comprehensive details about Power over Ethernet, the Wikipedia page provides an excellent resource: https://en.wikipedia.org/wiki/Power_over_Ethernet