Electricals lines on systems running in harsh environments are prone to failure.
Electrical disconnectivity is very common and could have severe consequences.
The project offer on-line, easy, cheap and very accurate way called Passive TDR to discover electricals disconnections and locate where they are.
The problem
We want to have a way to detect and locate faults in electronics communications line, without the need to shut-down the entire system, as traditional method require (like TDR).
The solution
Designing and implanting a passive method that will give us the advantages that TDR offers, without its limitations. Such a method will be referred to as pTDR. This method will use the DUT (Device under Test) own signals as input, tunnel those signals as output (so that the DUT functionally won’t be compromise), and use High Speed Counter to count the time that the signal is reflected (if any). Using the counter output, we can determine where the fault in the line (distance from the output) is. In case that there is no reflections, we can be sure that the line is good.
Results and conclusions
Using the pTDR IP we build we saw that such method can find disconnections on lines for all test cases we used (using coax lines). Also, when calibrated correctly, such method can give a very accurate estimation on how far the fault is (from the output).
Our conclusions from using pTDR is that it is very viable solution for cases when constant monitoring on communications line are needed while the system is online (cars, airplanes etc.)
