Locating bus cable break point in a local area network

A measuring system which can accurately locate an inaccessible break point over a local area network bus cable is described. The system utilizes sinusoidal signals instead of conventional narrow pulses as input test signals. It is shown that the variation of the amplitude with frequency in the resultant sinusoidal wave established over the cable length is periodic and that the periodicity is related to the break point distance. Thus the distance to the break point can be determined by measuring this period. Practical tests on a number of cable segments confirmed the viability of the approach. On account of its accuracy and modest equipment requirement, the method is valuable for break point location measurement over an Ethernet environment.