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Quantumdata 780 HDMI tester Now that HDMI sockets are standard on a wide range of LCD and plasma TV sets, set top boxes, DVD players and many computers, there is a need for a standard HDMI test source that can test this equipment. The Quantumdata 780 Handheld Test Instrument is a comprehensive solution which also provides digital audio test signals for DACs and Home Theatre receivers. Review by Leo Simpson H ere at SILICON CHIP we have been following the development of HDMI interfaces on TV sets and other equipment and wondering just how to test this equipment without having a very expensive line-up of test equipment. For example, on the internet you will see lots of claims about maximum length of HDMI cables for reliable operation. Some suppliers say the limit is 10 metres while others make considerably longer cables. And there are cables and cables – some long cables just don’t perform well. Nor is it simply a matter of hooking up a DVD player to an HDMI-enabled TV or projector and seeing if it works. There is the question of which level of HDMI is being used and what is the bit rate applied to the colour signals. Now, with the Quantum Data HDMI tester, a lot of those questions can be answered. And it is also possible to directly compare picture quality using defined video test patterns with HDMI, VGA and component video (YPbPr) cables. You cannot do this with any degree of certainty with a signal from a DVD player – even if it is stationary. So that is the background – now to Quantum Data. It is quite a compact instrument, measuring 250mm x 68mm x 163mm (W x H x D). It is battery-powered with nickel metal hydride cells to give about four hours of operation. It can also be run from an AC adaptor which will charge the batteries overnight. There are no controls as such, since all modes are controlled by the colour LCD touch screen, which measures 99 x 58mm. On the rear panel there are sockets for HDMI input and output and VGA, for testing of projects, TV sets etc, as well as TOSLINK (optical) and SPDIF coax outputs for testing the digital outputs of sources such as DVD players and set-top boxes. In addition, there is a USB socket and the DC input socket while on the These three pictures shows some of the audio test screens which control digital signals delivered via the TOSLINK (optical), SPDIF (coaxial) or HDMI outputs. 12  Silicon Chip siliconchip.com.au All functions of the Quantum Data tester and selected and controlled via the touch screen. The unit can test all products which use HDMI connectors. opposite panel is a socket for an SD card. When you first turn it on, the Quantum Data tester displays a home screen which gives four small patterns depicting video or audio patterns, Test Sink (TV, projector) and Test Source (DVD player or STB). If you are testing an LCD TV for example, you would touch the Video Pattern and it comes up with another screen of 15 patterns. These include colour bars, ramp/stair, raster, needles (white needle/black background etc), decoder adjust, convergence, pluge (black & white) and so on. Another screen gives a choice of checkerboard, zone plate, and master test patterns at 720 x 480, 1280 x 720 and 1920 x 1080 pixels, in progressive or interlace mode. In addition, quite a few of the pattern selections have a plus symbol in them. Double-tapping these brings up HDMI cables can be tested to the V1.3 standard at 8 bits and 12 bits. To the right is a report on a HD monitor tested via the HDMI output. siliconchip.com.au November 2009  13 Our photo and the printing process do not show the extreme resolution demonstrated by the 1920 x 1080 pixel test pattern. This standard BENQ monitor came through with flying colours. another screen which enables you to change the pattern parameters. For example, on the colour bar patterns, you can set colour saturation, you can have vertical or horizontal bars, change the number of bars (7 or 8), and so on. For the raster pattern you have can have Red, Green, Blue, Cyan, Magenta, Yellow or white, with or without an IRE label, you can set the IRE level and you can have a full raster or a window. Similarly, for the master test patterns, you can select HDMI or DVI, VGA (analog) outputs and for VGA you can have RGB or component video. DVI equipment must be tested with a HDMI to DVI adaptor (not supplied) while LCD monitors with component video inputs can be tested with a VGA to three RCA plug adaptor (which is supplied). DDC: PASS. We ran the tests for a number of cables, including a 15m cable, and they all passed. Cable test For testing a DVD player or set top box, you plug the HDMI cable from the player into the input socket on the Quantum Data, tap the “Test Source” screen on the home screen and then tap the “Analyser” screen button. It then displays a comprehensive report of the signal output such as the signal format (eg, 730 x 576), frame rate, progressive scan enabled, color space (YcbCr 4:4:4) and so on. You can also For HDMI cable testing, you plug the cable into the HDMI input and output sockets and press the start button. It runs the test and then displays the results as: +5V: pass 1080p (12 bits) 0 errors 1080p (8 bits) 0 errors 720p (8 bits) 0 errors Hot plug: PASS Source tests Left is another test screen from the Quantum Data 780 tester. The centre pic is one of the screens for selecting video test patterns, while at right is he home selection screen on the Quantum Data 780. 14  Silicon Chip siliconchip.com.au What is HDMI? Front and rear photos of the Quantum Data. The analog output enables testing of monitors with RGB or component video inputs. run the Audio Analyser and it will give a comprehensive report on the digital data. Sink tests To test HDMI monitors, you tap the “Test Sink” screen and you are presented with a choice of three buttons; EDID test, HDCP test and CEC test. Tapping the EDID button gives you another three screen buttons: Read, Copy to Rx and Reset Rx. Tapping the Read button runs a test which includes identifying the make and product ID of the monitor (TV, projector etc), its serial number, date of manufacture, and native timing, eg, 1920 x 1200 59.95Hz. Incredible, although not all this info agreed with that printed on the nameplate. The data can then be copied to the receiver port and downloaded to a PC via the USB port. Audio tests For audio tests, such as testing a DAC (such as the high quality DAC project in the current issues of SILICON CHIP) or a Home Theatre receiver, you connect an optical, SPDIF or HDMI cable and then select siliconchip.com.au the Audio Pattern screen. You then tap the optical, SPDIF or HDMI button and the Signal Type: Dolby 5.1, Dolby 7.1, DTS-ES 6.1, DTS-HD HRA or PCM Sine Wave. You then go into the next menu level to set up the tests. We ran the SILICON CHIP DAC through the PCM Sine Wave tests and could select the sample, the bits per sample (16, 20 or 24), the output channel, sinewave frequency, amplitude (level) and so on. Clearly, this is a very complex and capable instrument and in the few days that we had it we were just not able to come to grips with its full capabilities and nor did we have the necessary detailed information on all the test parameters. For example, we did not know what to expect in the qualitative results of the digital audio tests. Nor did we have sufficient info to interpret the high definition test patterns. Overall though, we were most impressed. For further information on price and availability of the Quantum Data 780 Handheld Test Instrument, contact Tekmark Australia Pty Lt, Suite 302, Level 3, 18-20 Orion Road, Lane Cove, NSW 2066. Phone 1300 811 355; website www.tekmark.net.au SC HDMI stands for High-Definition Multimedia Interface. It is essentially a standard which provides, in a single cable, an uncompressed, all-digital audio/video interface between any HDMI-equipped audio/video source, such as a set-top box, DVD player or A/V receiver and an audio and/or video monitor, such as a digital television (DTV), video projector, etc. HDMI has also started to earn wide acceptance as the interface between personal computers and A/V systems, particularly in home theatre. Because HDMI is digital, it offers the best video quality, as there are no lossy analog-to-digital conversions as are required for all analog connections (such as component or S-video). The difference is especially noticeable at higher resolutions such as 1080p. Digital video eliminates the softness and ghosting sometimes found with component video. Small, high contrast details such as text bring this difference out the most. HDMI supports standard, enhanced or high-definition video, plus multi-channel digital audio on a single cable. It transmits all ATSC HDTV standards and supports 8-channel, 192kHz, uncompressed digital audio and all currently-available compressed formats (such as Dolby Digital and DTS). HDMI has become the defacto standard digital interface for HD and the consumer electronics market. More than 700 companies have become adopters, with a forecast of nearly one billion HDMI devices installed by 2010. HDMI is the only interface enabling connections to both HDTVs and digital PC monitors implementing the DVI and HDMI standards. The HDMI standard. For more information, visit www.HDMI.org November 2009  15