Fault detection in fieldbuses with time domain reflectometry

Time domain reflectometry (TDR) is a well known method for fault location, especially in power distribution networks. The work presents the application of TDR for detecting faults in fieldbus wiring, since most of the faults in fieldbuses that are detected during initiation of operation are simply faults in wiring. These faults can be identified in the pulse reflection image by recognition of basic pulse reflection patterns. Because this method is faced with many practical problems, the paper introduces simulation as a new way to find faults in wiring in fieldbuses before the initiation of operation. During operation, faults in wiring can be detected in realtime with a differential method, if a TDR-function is integrated into the fieldbus.