Unusually Usual USB Connections

Unusually Usual USB Connections

Martina Horner is a psychologist known for pioneering the concept of “fear of success”. Her research focuses on intelligence and motivation. She has this to say about learning; “What is important is to keep learning, to enjoy challenge, and to tolerate ambiguity. In the end there are no certain answers.” Martina should have been in the AV industry. In this industry, at just about the time you think you’ve got something figured out along comes an ambiguous challenging learning moment for which there are no certain answers. I was recently asked a question about USB technology that turned out to be just such an experience.

Many devices that are not now, nor never have been, computers are being built with USB ports included in their palette of connectivity options. USB is probably the most ubiquitous electronic connection in our society. Everything from cellphones, e-readers, and Fitbits® to a refrigerator might have a USB connector.

TVs and displays often have a USB port to allow playback of movies, music or images from a thumb drive. AVRs have USB front and back to aid in both connectivity of portable sources (smartphones and tablets) and for control. Even the advanced switching, streaming and recording devices that lie at the heart of many commercial installations are peppered with USB ports for connection of hard drives and even cameras. The learning moment comes when you try to connect to them.

The call considered here came from a colleague who wanted to know why a USB hub wasn’t working with a very sophisticated device designed to mix, record and stream live lectures and meetings. There is a front panel USB port to allow for connection of a removable hard drive without the need to get into the rack. So far so good and everything works properly. But this particular install needed the ability to connect multiple hard drives from a short distance away. That’s when we learned that just because something has a USB port doesn’t mean it is a fully compliant USB host.

While it was possible to use a USB extender with the device and move the hard drive a few meters away, the device stubbornly refused to recognize a hub. Specifically it wouldn’t recognize three of the four ports of the powered hub. What was the problem? We’re still not 100% certain (I’m willing to tolerate ambiguity as long as there’s a work-around) but the current thinking is that the hub driver in the firmware was intended to support just one port and, while it might tolerate the connection of an active extender (typically “seen” by a USB host as a hub with just one port), it certainly wasn’t going to stoop to the level of recognizing those other empty jacks.

This prompted a series of highly unscientific experiments. The USB port of a 27-inch Samsung display was the first subject. No dice. Or should I say “no ports”. The display was having none of it. Plug the drive in directly and you could enjoy photographs, music and movies via a very intuitive OSD. Extend that port, or add a hub, and the display went on strike and refused to recognize any connected hardware.

Incidentally, a little more experimenting determined that the USB connection on this display (and many others like it) simply don’t deliver enough power to light up an Amazon Fire TV Stick, Roku Stick or Google Chromecast and a separate power supply is needed. Some internet research (read “I googled it”) reveals that highly limited USB power is common on displays, particularly at the commodity end of the market. At first blush I began to think that limited power and limited support of peripherals might be the beginning of a trend. But we all know one device does not a trend make.

The next test subject was the front panel USB input on an Integra DTR50.1 AVR. This is a very powerful receiver, but it’s already a few model years old. Plugging the drive in directly, I quickly found that the remote control allowed for the selection of multiple tracks or files to be played and displayed in various order via a powerful on-board GUI. Plug in a hub and, miracle of miracles, the AVR happily added four new sources to its menu in a right smart fashion. Not a problem, not a moment’s hesitation.

The conundrum here is that manufacturers build products to meet the requirements of a tightly defined user profile. In some instances they may have deliberately decided that fiddling about with hubs and multiple ports simply was not part of the plan. In other instances perhaps they just didn’t think users would ask the gizmo to undertake the connection under question. And in still other scenarios manufacturers are writing just about everything into the firmware to ensure that their products - that are not now, nor never have been computers - are capable of behaving just like a computer when connected to computer-like peripherals.

I don’t’ have an easy answer for this. I’ve yet to see any of this really spelled out in a user’s manual or in published specifications. The only real way to know if you can extend usual USB connectivity in unusual USB applications is to plug it all together and see what happens.

By- Joe Cornwall

Photo Courtesy of Joe Cornwall

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Joe Cornwall

Joe Cornwall

In 200 characters or less, I've been doing this a LONG time.

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