PoE Guide to TP-Link Access Points

What power supply method is supported by TP-Link devices?

Access Points may have various power supply methods, such as Passive PoE, Standard PoE and DC Power supply. Among them, PoE (Power over Ethernet) technology is used extensively due to its benefits (simplicity, mobility and reliability). Power over Ethernet is a technology to power up the device through the Ethernet cables. This would remove a separate cable solely for power use. Below table lists the supported power supply methods on TP-Link Access Points.

Will a Passive PoE AP be powered up by a Standard PoE power source device?

Standard PoE contains original IEEE 802.3af-2003 and updated IEEE 802.3at-2009. Both of them supply 48V DC input power. The difference is about the Maximum power delivered by PSE. 15.4W for 802.3af and 30.0W for 802.3at. A typical PoE system consists of a PSE and a PD. In standard PoE, both power sourcing equipment (PSE) and powered device (PD) should be complied with 802.3af or 802.3at. PSE will communicate with PD to negotiate its wattage requirements. Besides, 802.3at PSE is backward-compatible with 802.3af PD. So an 802.3af PD such as our EAP120 and EAP220 can be powered by either 802.3af or 802.3at PSE. While an 802.3at PD like EAP320, EAP330 can only be powered by an 802.3at PSE.

Passive PoE is a totally different power supply method compared to standard PoE. It needs a passive PoE adapter or injector which will not negotiate with PD, while merely supplies power at all times. Passive PoE adapter or injector can supply a stabilized DC power such as 9V/12V/24V for our access points. Therefore, passive PoE PD can’t be powered up through a standard PoE PSE, but it should be powered up with the proper Passive PoE Adapter or Injector.

Why can’t my access points support the recommended cable length?

Our outdoor AP can support up to 60m cable length for passive PoE adapter. Indoor device can only support up to 30m cable. This is a reliable length based on our field testing with network cable CAT5 above (see below photos). The cables on market now are on various levels of quality. So the real supported cable length depends much on the conductivity of the cable itself. The quality of electric conductivity of a cable varies depending on different outside coating, internal copper wire and RJ-45 plug as well as the joint quality.

When you find a network cable with our recommended length is not working well, you may need to try a different cable CAT5 above.

What’s the pinout rule of our Passive PoE access points?

Chart below shows the pinout of 802.3af standard A and B. Our passive PoE access points use the pinout of 802.3af mode B - with DC plus on pins 4 and 5 and DC minus on 7 and 8 (see chart below). Data is then on 1-2 and 3-6. 

Note: This chart above is from http://en.wikipedia.org/wiki/Power_over_Ethernet