9.28.2012

Power over Ethernet (PoE) is Getting Popular

Power over Ethernet (PoE) is Getting Popular

In 2.4GHz active RFID implementation, apart from the most popular 2.4GHz Active RFID model HKRAR-EMWF, which uses IEEE 802.11.2 b/g to communicate with PC, the POE member of this Empress reader series (HKRAR-EMPOE) is also getting popular and common in environmental monitoring or any data-gathering projects.




Power over Ethernet (PoE) is a technology that uses the power inside LAN cable to power up the devices such as IP camera, router, controller, gateway and RFID readers. By injecting power into the standard Cat-5 Ethernet cable with POE adaptor (or injector), the cable is providing 15.4W (48V) to the device and at the same time providing data transmission. It simplifies the network installation and maintenance.

The Advantages of PoE:

-          Little configuration or management required
-          Avoid using mains voltages hence more safe
-          Simplified installation and space saving
-          Easier for trouble shoot since data and power are on same cable
-          Ethernet cable can reach 100meters regardless on RF environment
-          Eliminate the need to hire skilled electrical contractor


Photo: Blue LAN powers up and exchanges data with Reader.

Precautions in Implementing a PoE system

1)      The maximum allowed continuous output power per cable specified in IEEE 802.3af-2003 is 15.4W. The 2.4GHz active RFID reader (PN:HKRAR-POE) reader only uses small amount of power (less than 1W), however, as a rule of thumb, a maximum cable length of 100m is still recommended.

2)      Reliable PoE adaptor (injector) must be used. Some low quality adaptor may not have certain circuit protection and power stabilization features, the reader can be damaged by the PoE adaptor. Here is a recommended model.



Photo: EMPOE reduces the total project cost by running on single LAN cable.


EMPOE works well with all 2.4GHz active transponders, including asset tags, temperature sensor tags, etc. Please visit this website for for detail for Empress 2.4GHz Active RFID Reader Series.

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