A good video on how to use the Elegiant Cable Tester we use is linked here.
To summarize it, this cable tester can test a cables wiring by using the “Network” setting.
Connect the cable to both the tone generator and the probe. Change to the “Network”. After changing it to that setting you should then be able to hit the “Test” button and see how the wires are connected on both sides. If one light does not light up, the wire is disconnected or dead. If the wires are crossed you will see the lights cross. If the lights do not go down the line “1, 2, 3, 4, 5, 6, 7, 8”, then your wires need to be checked and recrimped.