Communication line checker and communication line identification method

摘要

PROBLEM TO BE SOLVED: To provide a checker of a communication line which can be operated easily by anybody. SOLUTION: This checker is provided with a modular cord 2 having two core wires 2A and 2B connected to a communication line to be tested, a display part 5 for analog line identification connected in antiparallel between the core wires 2A and 2B while having light emitting diodes(LED) 5A and 5B to be emitted in mutually different colors while matching polarities by impressing a first DC voltage, and display part 6 for ISDN (digital) line identification connected in antiparallel between the core wires 2A and 2B while having LED 6A and 6B to be emitted in mutually different colors while matching polarities by impressing a second DC voltage higher than the first DC voltage.