Rohde & Schwarz and TSN Systems provide nanosecond-precision latency measurements for automotive Ethernet

08/28/2020

Advanced driver assistance systems (ADAS) require high bandwidth and low latency communications. Automotive Ethernet is becoming the de-facto communication solution to handle these requirements by offering higher data rates as well as time-sensitive network capabilities.

Together, Rohde & Schwarz and TSN Systems provide a comprehensive test solution for engineers who need to perform precise timing measurements on in-vehicle networks with nanosecond accuracy for Layers 1-3. In the collaboration, Rohde & Schwarz provides a tailored oscilloscope solution based on the R&S RTO, while TSN Systems contributes TSN Box, a hardware interface to the network and TSN Tools, a measurement and analysis software.

The test setup monitors an automotive Ethernet 100BASE-T1 communication link consisting of TSN Box 3.0 acting as talker, listener and test access point (TAP) device. The TSN Box 3.0 TAP device provides information to a PC with TSN Tools based on Layers 2 and 3. The TAP introduced 2x PHY delay for 100BASE-T1 at around 1.5 μs ±10 ns. The R&S RTO oscilloscope was used along with the R&S RTx-K35 bus measurements statistics option to measure and verify this timing accuracy in the physical layer of the automotive Ethernet signal (Layer 1). The mean time delay was measured to be precisely 1.5 μs with a max deviation of ±10.2 ns. In addition, the Qbv traffic (IEEE802.1) was generated by the TSN Box 3.0 with 500 μs cycle time resulting in a jitter ranging from 8 to 20 ns, which was verified by both the TSN Tools and the R&S RTO.

Read more.

www.rohde-schwarz.com