New devices extend PoE to legacy devices, and to the edge

Author : M Babb

01 January 2009

PoE (Power over Ethernet) is becoming so pervasive, industrial communications providers are extending its reach out to “edge” devices on the network (video surveillance cameras, wireless access systems, VoIP telephones, etc.), as well as legacy devices that were never intended to be powered by the communications bus.

N-Tron PoE splitter, for situations where it's difficult to run power

With the so-called legacy devices—and this could even be devices that don’t communicate over Ethernet—some end users are looking for ways to connect the power to them from their PoE systems. N-Tron’s 100-POE-SPL PoE Splitter may be the answer to some of these situations.

The PoE Splitter could be used in either of two ways:

1. to supply power any device that needs to have power, regardless of whether or not the device needs to be connected to an Ethernet network, or

2. to provide power to legacy Ethernet devices that have to be separately powered because they were built in the days before PoE.

On one side of the PoE splitter, it accepts a PoE cable as input. On the other side, the output, two cables come out: one with pure power, and the other with the Ethernet signal without power.

The splitter enables products that would otherwise require a dedicated power drop to be deployed with only a Cat5 cable. It is capable of providing 15.4 watts of power, the maximum allowable under the IEEE 802.3af specification. It is available with 12, 24, and 48VDC output.

This solution is ideal in situations where it would be difficult or expensive to run power, or for a temporary installation. Ethernet enabled video cameras, wireless access points, access control devices such as card readers as well as other devices located in areas where power is not readily accessible are perfect candidates for the PoE Splitter.

As part of N-Tron’s iPOE line, it is protected by a metal enclosure and withstands wide operating temperature range of -40ºC to 85ºC and harsh industrial environments.

PoE on the edge
For users of Ethernet-enabled video surveillance cameras, wireless access systems, VoIP telephones and other ‘edge of network’ devices, the ability to drive these products via Power over Ethernet (PoE) from a compact network switch can be an advantage.

But much of that benefit is lost if the Ethernet switch itself requires a separate power supply before it can be connected into the mains. GarrettCom Europe has addressed this issue with its power supply chassis integrated within the hardened Ethernet edge switch.

With its integrated power supply, a single PES42P unmanaged edge switch can power up to four PoE enabled devices from a single AC mains outlet, as well as a high-speed fibre media uplink to the control centre.

The switch provides a total of six Ethernet ports. Four ports are always RJ-45 for PoE. The remaining two ports can be user specified as two 100Mb fibre ports, or one fibre and one copper port, or two copper ports.

The PoE ports feature auto-sensing technology so that they provide power only to attached 802.3af PD devices. If proprietary PoE or non-PoE devices are attached, the auto-sensing feature ensures they will not be damaged. The ports discontinue supplying power when the PoE devices are disconnected, and support the PSE (Power Sensing Equipment) standard for over-current protection, under-current detection and fault protection.