HDMI, or High Definition Multimedia Interface, was first conceptualized as a medium for transferring high definition video and audio signals over a single cable. Over the years, this interface has become widely adopted and now dozens of cable manufacturers and electronics companies develop their own versions of HDMI products that are sold to millions of consumers daily.
HDMI.org is the official HDMI organization comprised of multiple companies including Maxell, Ltd., Koninklijke Philips Electronics N.V., Lattice Semiconductor Corporation, Panasonic Corporation, Sony Corporation, Technicolor S.A. (formerly known as Thomson) and Toshiba Corporation, which conceptualized and continue to oversee the development of HDMI. This organization developed the concept of creating a single cable that was able to transfer uncompressed high-definition video, multi-channel audio, and data in a single digital interface. This organization includes the HDMI Licensing Administration, which administers the HDMI Compliance Test Specification to various HDMI adopters. To get this license, adopters must undergo a set of compliance tests, where if passing, their product can be recognized and labeled as HDMI certified.
Photo by Obtaining HDMI Certification
In order for HDMI cables to become certified, adopters first must perform specific self-tests on a representative sample of their cables. The HDMI Compliance Test Specification specifies the required testing procedures that must be performed, as well as the minimum requirements necessary to meet the standard. Secondly, once developed, HDMI adopters must submit their first product of each licensed product type, whether this be a source, sink, repeater, or cable to an HDMI Authorized Testing Center. Once their licensed product passes this initial inspection, adopters are not required to submit any further samples of the same product type.
One of HDMI’s cable certification program, called the Premium HDMI Cable Certification Program, performs various tests on cables incorporating newer HDMI 2.0 technology. Cables tested in this program are verified to ensure they fully support the 18 Gbps bandwidth from HDMI 2.0b, as well as an electromagnetic interference (EMI) noise test to ensure cables minimize interference with wireless signals. “Premium High-Speed HDMI Cables “or “Premium High-Speed HDMI Cables with Ethernet” on their products.
While these compliance tests determine if the HDMI product meets the relevant spec, they do not go further in depth to determine the performance of the licensed product. These tests provide the minimum requirements to meet compliance, and while they do catch design errors, they do not always determine conformation to High-Definition Multimedia Interfaces or successful interoperability with other HDMI products.
Testing Beyond Certification
There are many accounts of HDMI cables acquired by consumers exhibiting image or audio transfer issues, whether it be cheap, expensive, or even HDMI certified cables. Many HDMI users have experienced fuzzy, discolored picture, intermittent image and sound, or even no sound at all. This leads us to the question: is cable certification enough to determine the quality of all HDMI cables mass-produced thereafter? With all the variables involved in manufacturing, it is still crucial for manufacturers to continue to test and oversee their products or there could be repercussions.
Even after cable certification is granted to HDMI cable manufacturers, safety and quality testing during and after production should be an integral part of the manufacturing process. When manufacturing cables, including HDMI, cable companies will often use human intervention to assemble the more intricate components of these cables as complete automation is not feasible. In these cases, companies should expect the unexpected as this added level of variability is impossible to eliminate and increases the margin for error exponentially.
Currently, cable manufacturers may use their own versions of production line testing, like testing for functionality or HDMI lock, but these tests do not always look below the surface to ensure the internal infrastructure is correctly assembled and operating as expected according to specification or even as advertised. Even if a cable passes these inspections, it does not automatically correlate to a quality cable. Some also go further to implement statistical process control, which performs a test on randomly selected cables and then determines the failure rate probability within all cables produced using statistical calculation. While this method is adequate, this type of testing still neglects a large amount of cables allowing bad ones to pass through.
Until now, testing each and every cable during production has not been feasible for cable manufacturers. There has not been a single machine that performs a quick, affordable and comprehensive analysis on cables – until now. With the Advanced Cable Tester v2, cable manufacturers can now perform individual quality control.
Advanced Cable Tester v2 Supports Testing HDMI
The Advanced Cable Tester v2 supports the analysis of HDMI-A to HDMI-A cables. HDMI cables are tested for pin continuity including shorts and opens with a dynamic visualization of the test results. Manufactures can even test continuity of individual or grouped HDMI pins. It also measures the DC resistance with milliohm precision on ground and power wires and ohm resolution on most other wires. Finally, a signal integrity test of data lines up to 12.8 Gbps per channel is performed, accompanied by an eye-diagram with a mask per cable specification providing a visualization of the signal quality.
This tester allows for users to evaluate the insertion loss within the cable, which is a common concern with the more recent HDMI specifications, and can greatly affect the overall cable performance.
This tester is designed for a variety of environments, allowing developers to pre-test cables in the lab or perform quality testing on cables during production. This next generation cable tester focuses on supporting mass-scale production, where the cost and time taken to perform tests have dramatically improved. Now, anyone at any skill level can determine the validity of a cable using the Advanced Cable Tester v2. This tester includes an LCD screen that displays a pass or fail result with each cable insertion. For a more in-depth analysis, testers can review on spot or remotely using Ethernet for a more detailed report of each individual test. Because each subtest flags errors not within spec, it is easy to discover the flawed portion of the cable.
To learn more about how the Advanced Cable Tester v2 supports HDMI testing, please visit our website.