Cable segment test method for locating resistance variations in local area network - supplying measuring pulses and evaluating reflected pulses using analogue=to=digital converter and two separate channels, with memory storing values

摘要

The test method involves supplying measuring pulses to one end of the tested cable section and detecting the reflected pulse response at the same cable end, supplied to 2 separate channels (6,7) each having an A/D converter supplying digital sample values to a single memory (8). The A/D converters receive respective clock signals (T1,T2) with the same sampling frequency which are offset by one half period so that the digital sample values are fed to the memory (8) in alternation. The measuring pulse duration (tMP) is pref. greater than the sampling period (tA). USE/ADVANTAGE - For Time Domain Reflectometry appts. Improved cable fault location accuracy compared to oscilloscope method.