Functions: Can test corresponding double-twisted cable 1, 2, 3, 4, 5, 6, 7, 8 and G, meanwhile, can judge wrong connection, short circuit and open circuit; Test of double-twisted cables: switch on teh power. (S is slow automatic grade, M is manual) Put cables into both main tester and remote tester. The lights of the main tester will turn on sequently from 1 to G. Main Tester: 1-2-3-4-5-6-7-8-G, Remote tester: 1-2-3-4-5-6-7-8-G (RJ45) 1-2-3-4-5-6------(RJ11) 1-2-3-4----------(RJ11); Following are abnormal connections: If one cable, fro example cable NO.3 is open circuited, the two No3 lights of the main tester and remote tester and remote tester will not turn on. 2. If several cables are not connected, several lights will not turn on respectively. If less than two cables are connected, none of the lights is on. 3. If two ends of a cable is disordered, for example No.2 and No.4 then dispalys on: Main tester: 1-2-3-4-5-6-7-8-G, remote tester: 1-4-3-2-5-6-7-8-G. 4. If two cables are short circuited, neiter of the corresponding lights is on of the remote tester while main tester remains unchanged. If three cables, including three, are short circuited, none of the corresponding lights is on. If test patch panels or wall piate outlets, two cables withc can match each other (110P4-RJ45) will be connected to the tester.