The PoE Tester is suitable for testing the PoE / PoE + connections to IEEE 802.3af and IEEE 802.3at compliant with a voltage of 37-57V for. Other standards as Telephone / ISDN voltages are not supported. Connect the RJ45 connector of the PoE tester using the supplied short cable, the other end of the cable to the test RJ45 port. The following display options are available: 1. The LED lights Endspan: There is a PoE voltage via pin 1,2,3,6 in Endspan mode to the socket. 2. The LED lights Miadspan: There is a PoE voltage via pin 4,5,7,8 in Midspan mode to the socket. 3. No LED lights up: The tested RJ45 connector does not have PoE voltage.