Complicated and expensive. If this is your perception of machine vision for industrial automation, it’s time to reconsider. Choosing the right video interface – the hardware and software used to format imaging data and send it to a computer for analysis or display – can help designers and end-users reduce complexity, lower costs, and gain performance advantages.
Traditionally, industrial vision systems have used point-to-point video interfaces based on analog, low-voltage differential signaling (LVDS), or Camera Link® standards. The dedicated cabling is costly, heavy, and difficult to manage and scale. In addition, these interfaces require a PCIe frame grabber to capture the data at the computer.
This changed with GigE Vision® and USB3 Vision™, which standardized the delivery of video over Ethernet and USB 3.0 cables. As these standards gain wide-scale adoption, an increasing number of compliant products are now available as off-the-shelf solutions. For retrofit projects, external frame grabbers convert feeds from existing cameras into more manageable GigE or USB3 Vision video. Many camera manufacturers also offer native GigE and USB3 cameras for industrial vision applications, and embedded video hardware can be combined with custom sensors or smart camera heads for specialty applications.
With this in mind, let’s revisit “complicated and expensive” concerns.
GigE Vision and USB3 Vision interfaces transfer imaging data directly to Ethernet or USB 3.0 ports found in most computers. System designers can choose from less expensive, ruggedized, smaller form factor computing platforms – such as embedded processors, single-board computers, laptops, and tablets – for control and analysis.
The flexible, lighter Ethernet and USB cables cost less and are simpler to install and maintain than the bulky cabling and connectors of legacy interfaces. With the extended reach of Ethernet– up to 100 meters between network nodes over standard Cat 5/6 copper cabling—designers can move processing computers away from harsh environments. Imaging data can be multicast or aggregated over the switched Ethernet network. USB3 Vision interfaces are suited for higher bandwidth, shorter distance applications, with vendors introducing cabling solutions that extend the distance between camera sensors and processing units.
In existing installations, GigE Vision and USB3-compliant external frame grabbers allow an end-user to preserve capital investments while gaining performance and maintenance advantages.
In a web inspection application, GigE Vision external frame grabbers fully support required point-to-point performance, with the networking flexibility to multicast image data to multiple computing platforms simultaneously using an off-the-shelf Ethernet switch. Designers can optimize individual computers for different types of defects, rather than pairing a dedicated PC to each camera. If a primary computer is taken offline, inspection can be assumed by backup computers without switching cables or changing software settings.
Basing new designs or upgrading existing installations on GigE and USB 3.0 video interfaces, machine vision systems can help end-users increase efficiencies, improve productivity and ultimately boost profitability.
John Phillips is senior product manager with Pleora Technologies, the world’s leading supplier of video interfaces for system manufacturers and camera companies serving the military, medical, and industrial automation sectors. Find out more at www.pleora.com.