Automated compliance test solution for high speed Ethernet cables

Your task

Testing high speed cables for data centers or consumer electronics is a highly complex task that requires precision, support for higher frequencies and a multiport setup. Conventional manual testing with a 4-port vector network analyzer is a time consuming task and can be prone to human error. High speed cables are constructed of numerous copper wires organized as differential signal paths, commonly referred to as “lanes”. The number of lanes dictates the maximum transfer rate supported by the high speed cable. For example, the latest IEEE Ethernet PHY specification, IEEE 802.3ck, supports single lane data rates of 100 Gbps. This allows data rates of up to 800 Gbps in a high speed Ethernet cable in the QSFP-DD form factor with 8 lanes.

As the number of lanes in the cable under test increases, the task of testing for compliance to the IEEE802.3 standard becomes more tedious, complex, and time consuming. This is mainly due to the increased number of reconnections when using a 4-port VNA.

Verifying compliance with the standard requires testing the transmission of each lane (through), as well as TX to RX crosstalk of all neighboring lanes – near end crosstalk (NEXT) and far end crosstalk (FEXT). To measure all S-parameters, a design or test engineer using a conventional setup with a 4-port VNA needs to reconnect the ports to the cable several times to complete the testing of a single cable. Compliance testing can take a full day for each cable, as is the case for 8 lanes.

Rohde & Schwarz solution

Rohde & Schwarz has introduced a fully automated compliance test solution, based on the R&S®ZNrun vector network analyzer test automation suite. It allows easy, precise and time-saving standards-compliance testing for high speed cables.

The compliance test software automatically performs all of the required measurement steps, and it post-processes all of the measurement data according to the standard specifications: channel operation margin (COM) and effective return loss (ERL). It automatically generates a comprehensive test report, including the overall pass/fail verdict. The software suite makes it easy for users to analyze the test results and validate the cable under test, saving a tremendous amount of time while minimizing human error.

The automated Rohde & Schwarz compliance test solution for high speed Ethernet cable assemblies combines the precision and high performance of Rohde & Schwarz vector network analyzers with the flexible R&S®OSP open switch and control platform and the R&S®ZNrun software suite to make measurement faster, easier, and more reliable.

Fully automated multiport VNA measurements made easy and time efficient

R&S®ZNrun with the R&S®ZNRUN-K4xx compliance test automation options offers a straightforward test procedure, using three simple steps: setup, calibrate, and measure. Each automated step is optimized for minimum calibration and measurement time. Smart cable handling eliminates the need for tedious port reconnections in the test setup. By automating data collection and results processing, the R&S®ZNRUN-K4xx compliance test automation options provide reproducible results and significant time savings.

Beyond compliance: software capabilities offering more than just compliance tests

Apart from fully automated compliance tests, R&S®ZNrun adapts flexibly to a range of testing needs. Designers and test engineers can use the R&S®ZNrun software suite to debug setups and cables. Measurement steps can be deselected – e.g. to perform a fast test for an initial evaluation of the cable. Users can set measurement parameters such as frequency range or sweep time to custom values in order to perform initial plausibility measurements before starting a full compliance test.

Recommended configurations

Selection tip – types of cable under test and recommended R&S®OSP open switch and control platform