Case Study - Advanced Cable Tester v2 - Lightware Visual Engineering Plc

Lightware Visual Engineering Plc

Challenge:

To ensure quality control across their products, Lightware needed a reliable cable testing solution. This became especially pertinent when launching a new product, which prompted them to collaborate with a cable supplier to develop a 3m USB-C cable that met specific wattage and gigabit performance standards. However, ensuring durability at this length proved challenging. To ensure structural integrity, the quality team worked closely with the supplier, refining parameters as needed. This required a solution to perform quick, comprehensive testing after each iteration to verify compliance with performance standards.

Solution:

The Advanced Cable Tester v2 allowed their teams to run comprehensive tests on cables, providing insight into key cable attributes, such as GND and VBUS DCR parameters, and E-Marker content, and signal integrity measurements with eye diagrams. This was essential in verifying whether the requested changes aligned with industry standards and ensured the cable's structural improvements were on the right track.

Benefit:

The expansive tests and easy-to-read results of the Advanced Cable Tester v2 significantly shortened the amount of time spent on verifying the structure and performance of the USB-C cable at various stages of the development process. This streamlined overall operations and saved on additional costs in the quality department.

Introduction

Lightware Visual Engineering Plc is a leading manufacturer of professional audio/visual (AV) management solutions, specializing in the development and manufacturing of HDMI, DP, USB-C switches, as well as conference room devices that seamlessly integrate with other top AV brands. In addition to these offerings, Lightware offers professional cables designed to complement their devices, ensuring reliable video and audio transmission with zero loss of performance or quality. As part of their dedication to delivering high-quality, reliable products, they conduct rigorous cable testing as a routine part of their quality assurance process. This commitment became even more critical when collaborating with a cable supplier to develop a durable, high-performance USB Type-C cable for a new product.

Background/Problem

Lightware specializes in the development and manufacturing of HDMI, DP, USB-C switches, and conference room devices that facilitate solutions integration. In the coming year, they plan to put an increased focus on supplier and product qualification.

Lightware’s cable division ensures high-quality, reliable connectivity by managing the entire product lifecycle—from identifying customer needs to overseeing qualifications, internal processes, manufacturing readiness, and field quality. With a focus on electromagnetic compatibility (EMC) and signal integrity (SI), their team also measures and verifies cable prototypes provided by suppliers.

In prior testing to support manufacturing, they accomplished this solely by conducting plug tests, which examined the real-life behavior of products by connecting cables to other professional AV devices. These tests were slow and often had other limitations, sometimes requiring expensive equipment and experienced staff on specific cases.

Seeking to find a new solution that could verify a cable’s infrastructure, performance, and conformance to standards more quickly, Lightware adopted the Total Phase Advanced Cable Tester v2 after being introduced to the product by an AV industry partner. They found that the device had the ability to verify various cable types against required standards in seconds at an affordable price, successfully meeting their goal of finding a solution that balanced cost and capability.

Technical Approach

In 2024, Lightware launched a new product project that would require a 3m USB-C cable capable of powering up to 100W and signaling up to 10 Gbps with their design. To help the quality team and cable supplier expedite the testing and development of this cable, the Advanced Cable Tester v2 was used to assess the USB-C and USB-A to USB-C cables, ensuring quality and durability at the cable length. This included focusing on the GND and VBUS parameters, reviewing the signal eye diagrams, and verifying E-marker content.

Advanced Cable Tester v2 Parameters

The Advanced Cable Tester v2 performs a variety of quality of safety checks on USB, HDMI, and DisplayPort cables.

Pin Continuity Test

The Pin Continuity test analyzes the cable for any shorts or opens of various pins by applying voltage at one end of the cable and measuring the incoming signal at the opposite end of the cable. The following tests are conducted to ensure proper configuration: VBUS to Ground short, CC/VCONN to Ground short, VBUS to CC/VCONN short, shorts between all other pins, and continuity and mis-wires of defined and present pins.

Example of a passing Pin Continuity test on a USB Type-C cable is shown here:

ACT v2 Pin Continuity Test

DCR Test

The Direct Current Resistance (DCR) test measures the DCR for all wires except high-speed data lines, and measures the DCR for all power and ground pins, as well as the total DCR of the entire USB-C cable. This test is performed by applying current at one end of the cable and then measuring various points along the cable to determine the resistance.

This test allowed Lightware to pinpoint a slight deviation in the resistance measurements in the parallelly routed GND lines of their Type-C cable, an issue that can go undetected by relying solely on statistical process control. This enabled them to identify a soldering problem, which led to a corrective action with the cable supplier.

Example of a failing DCR test on a USB Type-C cable is shown here:

E-Marker Verification

An E-marker is an integrated chip within a USB Type-C cable that stores the cable’s characteristics and specifications. Verifying E-marker content ensures the cable accurately reports its capabilities, including power capacity, data rates, and manufacturer details. By conducting this test, Lightware quickly confirmed compliance and functionality, ensuring reliable USB Type-C connections.

Example of a passing E-Marker test on a USB Type-C cable is shown here:

Signal Integrity Test

The Signal Integrity test measures the performance and signal quality of the cable by evaluating the differentially paired wires. Configurable from 1,030 MHz to 12.8 GHz, it can test up to five differential pairs. The test assesses signal quality through a speed test and provides easy-to-read eye diagrams that visually represent signal integrity. A well-made cable will display a wider eye, while a lower-quality cable will show a smaller eye opening. These diagrams include a mask to reference the Horizontal Eye Opening (HEO) and Vertical Eye Opening (VEO) values.

Through these tests, Lightware was able to quickly and thoroughly verify that their cables met the required performance and signal quality standards.

Examples of passing and failing signal integrity assessments on USB Type-C cables are shown here:

ACT v2 Signal Integrity pass

ACT v2 Signal Integrity Fail

Refining Cable Quality Through Testing and Iteration

By using the Advanced Cable Tester v2, Lightware was able to quickly identify the resistance value deviance, which led to the discovery of the soldering issue on parallelly-routed GND lines. The resistance measurement tests proved to be valuable in pinpointing and addressing this problem. With these insights, Lightware could adjust the cable parameters as required, using the Advanced Cable Tester v2 to verify that each change met the supplier’s required standards. This iterative process ensured that the cable’s structure was continually optimized, ultimately meeting the desired specifications.

The Advanced Cable Tester v2 was fundamental in discovering these errors, as it measures cable characteristics that are beyond the scope of traditional statistical testing. They were able to perform comprehensive cable analysis across multiple test attributes, evaluating the cable as a whole in just seconds. This significantly shortened the cycle time for incoming tests, saving on labor costs for the quality control department. Because of the success with this tool in this project, Lightware is currently working on expanding test ranges to include HDMI, DP, and USB-C active cables.

Conclusion

To uphold quality standards for their products and cables, Lightware needed a fast, compact tool capable of evaluating cable efficacy against required specifications. They sought a device that could support both development and manufacturing activities. With the Advanced Cable Tester v2, Lightware was able to quickly test a broad range of cable attributes in seconds, including GND and VBUS DCR parameters, E-marker content, and signal quality with eye diagrams. This greatly streamlined their operations, reduced costs, and ensured reliability throughout prototyping and production.

Quote

“The Total Phase Advanced Cable Tester v2 offers an excellent balance of capability, efficiency, and cost. Given the needs of our growing business unit, I am very satisfied with the product, and it is definitely worth the investment.” – Zoltán Somodi, Cable Portfolio Product Manager

Product Brief

The Total Phase Advanced Cable Tester v2 is the quickest and most convenient way to comprehensively test USB, HDMI, and DisplayPort cables. Combining blazing fast performance with a low cost-per-test, this cable tester enables rapid spot-checking of cables with easy-to-understand reports for 100% test coverage in lab and production environments at a fraction of the price, time, and labor versus other solutions. With high precision, accuracy, and thorough test coverage, the Advanced Cable Tester v2 provides real-time results for pin continuity, DC resistance, signal integrity, E-marker, and other tests to ensure cables meet the required standards.