The device receives its power over IEEE 802.3af Power over Ethernet (PoE) and communicates with other system devices over the Ethernet network. The maximum power consumption from the PoE switch is 4-watts if the 1516LI-E expansion module is used. The maximum power consumption is 3 watts if the expansion unit is not used. If PoE equipment is not available, an input is provided for an alternate 48VDC power supply. A green LED is provided to show that the unit is powered on.