TEST MONITOR INCLUDING SIGNAL SEPARATOR AND DATA RECORDER

A test monitor extracts waveforms from a differential transmission line of an automobile network without disrupting the differential transmission line, and stores the data decoded from the extracted waveforms. The test monitor includes a first input configured to receive a voltage waveform from a voltage probe electrically coupled to the differential transmission line that electrically connects a first ECU device and a second device, a second input configured to receive a current waveform from a current probe electrically coupled to the differential transmission line, and one or more processors configured to receive the voltage waveform and the current waveform and determine a voltage of the first ECU device and a voltage of the second device based on the voltage waveform and the current waveform. The test monitor may be embodied in an FPGA. The test monitor enables monitoring of message transfers across a network in a non-intrusive and non-invasive manner, without the necessity of using a repeater or switch.