With more than 10 billion devices in the market already, USB is undisputedly the most successful computer connection interface to date. But for machine vision applications, USB 2.0 has been only a minor player due to relatively low throughput rate (480 Mbit/s) and distance reach (5 m) compared to rival vision camera interfaces like FireWire, GigE Vision, and Camera Link.
Considerable excitement was generated when the Automated Imaging Association (AIA) announced it would be developing a new camera specification called USB3 Vision based on USB 3.0. The standard having been formally published last January, USB3 Vision cameras support up to 5 Gbit/s to produce high-quality resolution, vibrant colors, and high frame rates comparable to Camera Link at a fraction of the total solution cost.
The only flaw with this technology is the distance limitation. Not all copper cables can support USB 3.0ís higher bandwidth at any appreciable distance. While great strides were made to improve throughput from USB 2.0ís 480 Mbit/s to USB 3.0ís 5 Gbit/s, distance took a step backward from 5 m to 3 m.
Fiber-optic cabling is the obvious choice over copper to increase distance, especially for newer transmission standards such as OM3 multimode fiber. Fiber offers plenty of benefits. The cable has a small diameter, which allows for easy and convenient installation and great future-proofing by supporting increasing bandwidths. While still carrying a premium over copper cables, fiber costs have come down considerably over the past few years. Fiber not only facilitates throughput and distance, it also offers electrical isolation, which is a requirement for many critically sensitive medical and military applications. It can also be manufactured to be flexible enough for tight locations or moving parts.
The stars seem to be aligned with USB 3.0 and fiber to work together to resolve the distance gap. But itís never quite that easy. Sending USB 3.0 data across fiber isnít going to magically get high-definition vision cameras running at 100 m from your control center. Thatís where ExtremeUSB extension technology comes into play to complete the solution.
ExtremeUSB has long been the extension standard for USB 1.1 and 2.0, and is now bridging the gap for USB3 Vision. It supports plug-and play-functionality (no software drivers required) and is compatible with all popular operating systems. ExtremeUSB 3.0 extenders are designed to extend USB3 Vision-compliant applications up to 100 m over OM3 multimode fiber, and have been validated by machine vision camera leaders like IDS, Lumenera, NET, Point Grey, The Imaging Source, Ximea, and others.
Glenn Antonelli is the vice-president of marketing at Icron Technologies and has more than 20 years of experience in strategic marketing.