D-Link DAP-2590 - AirPremier N Dual Band PoE Access Point User Manual page 12

Section  - Installation
Connecting PoE (Power over Ethernet)
Connect one end of an Ethernet cable (included with your package) to the LAN port on the DAP-2590 and the other end of the Ethernet cable
to either your computer or to your PoE switch. The AP can be powered on by a PoE switch or by the power adapter shipped with the AP.
D-Link DAP-590 User Manual 1