Method and ethernet physical layer device for detecting, classifying and localizing cable faults of an ethernet physical cable, particularly an automotive ethernet PHY, using a time domain reflectometry algorithm

A method for detecting, classifying and localizing cable faults of an ethernet physical cable, particularly an automotive ethernet PHY, using a time domain reflectometry algorithm, comprising the steps:

• sending through a transmitter a first finite duration diagnosis pulse signal to the ethernet cable,
• receiving by a receiver first reflections from the ethernet cable in response to the first diagnosis pulse signal,
• extracting a first reflected signal by subtracting the send first diagnosis pulse signal from the received first reflections,
• detecting a fault of the ethernet cable by comparing the first reflected signal to a predetermined threshold, wherein a fault of the ethernet cable is detected when the first reflected signal exceeds the predetermined threshold,
• classifying the type of fault of the detected fault based on the polarity of the first reflected signal, wherein the fault is an open when the first reflected signal is positive and a short when the first reflected signal is negative,
• sending through the transmitter a second finite duration diagnosis pulse signal to the ethernet cable,
• receiving by the receiver second reflections from the ethernet cable in response to the second diagnosis pulse signal,
• extracting a second reflected signal comprising the send second diagnosis pulse signal and the received second reflections,
• detecting a first peak in the second reflected signal relating to the send second diagnosis pulse and a second peak in the second reflected signal relating to the received second reflection, and
• localizing the detected fault of the ethernet cable by determining the time difference between the detected first peak and the detected second peak.