Remote testing of a communications line

摘要

Apparatus and method for remotely measuring characteristics of a communications line (4) wherein a receiver unit (8) is connected a remote end of line (4) between conductors (10,12) of the line (4) and a sender unit (6) is connected to the other end of line (4) between conductors (10,12). On depressing a function key or button on receiver unit (8) representative of a characteristic of line (4) to be measured, the receiver unit has a signal generator which transmits a unique signal or code identifying the characteristic to the sender unit (6) along line (4). The sender unit (6) detects the unique signal and passes the signal to a microprocessor which controls switching means to connect the corresponding circuitry between conductors (10,12), based on the unique signal or code, to allow the characteristic to be measured.