Test monitor including signal separator and data recorder

A test monitor for a network including a differential transmission line, comprising:

• 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;
• 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 one or more processers further configured to store data represented by the voltage of the first ECU device as first stored data and a voltage of the second device as second stored data;
• and
• a memory for storing the first stored data and the second stored data;
• in which the first input and the second input comprise a first channel, the test monitor further comprising a second channel including:
• a third input configured to receive a second voltage waveform from a second voltage probe electrically coupled to a second differential transmission line that electrically connects a second ECU device and a fourth device;
• a fourth input configured to receive a second current waveform from a second current probe electrically coupled to the second differential transmission line;
• the one or more processors configured to receive the second voltage waveform and the second current waveform and determine a voltage of the second ECU device and a voltage of the fourth device based on the second voltage waveform and the second current waveform, the one or more processers further configured to store data represented by the voltage of the second ECU device as third stored data and a voltage of the fourth device as fourth stored data;
• and
• the memory for storing the third stored data and the fourth stored data.