Automation Technologies 3/2014

Machine Vision Camera

Machine Vision Camera change with potential: USB 3.0 instead of FireWire Basler ace USB3 Vision cameras are available in resolutions from VGA to 14 MP; they have attractive prices and are easy to integrate René von Fintel How long will I be able to maintain my FireWire camera system? When should I switch, and which interface should I pick? Users of FireWire cameras around the world are wondering these things at the moment. The new USB 3.0 interface and its standard USB3 Vision are an attractive successor due to the technical proximity to FireWire. Basler, a globally active developer of industrial cameras, explains the backgrounds and perspectives. Author: René von Fintel is Team Leader Product Management at Basler AG in Ahrensburg, Germany back to current issue AUTOMATION TECHNOLOGIES 3/2014

Machine Vision next page FireWire doubtlessly is one of the most successful camera interfaces in the world. However, their life cycle is slowly coming to an end. Users of FireWire cameras will be facing the question of how to continue with their camera system in future and which interface to switch to in the medium term. Generally, they have several to choose from. The most important interfaces that are currently an option are USB 3.0, Gigabit Ethernet and Camera Link. Each interface technology has some specific benefits. Gigabit Ethernet is limited to a bandwidth of 100 MB/s, but offers benefits because it can use very long cables (up to 100 m) and makes it easier to set up multicamera systems. Camera Link Full is based on a frame grabber setup, but offers a bandwidth of up to 850 MB/s. Generally, the closer the interfaces are to each other in their technical principles, the easier it will be to switch. This specifically applies when switching from USB 2.0 or FireWire to USB 3.0. The reason for this is that FireWire is no longer supported. There are various reasons for switching from FireWire to another interface. The most relevant ones most certainly are: n FireWire hardware is growing more and more expensive and more and more difficult to procure. It will no longer be available in the medium term. n Changes to the software or transfer to any other operating system require a change. Windows 8 no longer offers natural FireWire support, while the 3.0 Host Controller can be used at once without even installing any drivers. n The bandwidth has grown insufficient for current and, particularly, future requirements to the Vision system, such as higher frame rates, higher resolution and a different pixel format. n Savings in the overall system justify the one-time integration effort quickly. The technology: FireWire versus USB3 Vision It is often said that USB 3.0 and its standard USB3 Vision are the most logical and recommended replacement due to the very similar technical properties. The two interfaces are not only similar, but USB 3.0 also offers true added value, as the table makes clear (see figure 1). Two other important properties should be mentioned: CPU-load and real-time capability. Even data rates in excess of 350MB/s will hardly put any strain on the CPU using USB 3.0, due to its direct memory access on the host computer. Blocks are reserved before image transfer to enable the mechanism to 01 Technical data by FireWire and USB3 Vision in comparison AUTOMATION TECHNOLOGIES 3/2014