Automatic fault location in cabling systems

A method and apparatus ( 12-20, 32 ) for automatically locating faults in a network of signal carriers (cables) utilises an interrogation waveform which is pulse-like in form and receives composite reflected signals from the carriers which are a time distributed collection of individual reflections. These are sampled and compared using the function of an adaptive filter ( 52 ) to minimise the difference signal. The difference signals are analysed to determine significant points of departure which identify the fault location which is then represented as a distance value.