Rohde & Schwarz and TSN Systems offer a solution for test engineers who need to perform precise time measurements on in-vehicle networks with nanosecond accuracy for layers 1 to 3. The oscilloscope solution is based on the R&S RTO with hardware interface to the network, TSN Box, and the TSN Tools measurement and analysis software. The setup monitors an automotive Ethernet 100BASE-T1 communication connection in which the TSN Box 3.0 functions as a talker, listener and TAP. In TAP mode, the box provides information to a PC with TSN Tools based on layers 2 and 3. The TAP introduces a 2x PHY delay for 100BASE-T1 of about 1.5 µs ±10 ns. Together with option R&S RTx-K35, the R&S RTO measures and verifies this timing accuracy on the bit transmission layer of the automotive Ethernet signal (layer 1). The determined average time delay is exactly 1.5 µs with a maximum deviation of ±10.2 ns.