Kendall-Jackson facility, four cameras take different images, and the system patches them together to check the entire label. 

That requires more than simple processing power. The network that links these cameras to the host PC has to transfer large video files at speeds fast enough to give the controller time to make a decision before a faulty part gets too far down the production line. The latest version of Ethernet has the bandwidth needed to transfer images from many cameras.

“With Gbit Ethernet, you’re not limited in the number of cameras you can link to the host. You’re limited by processing power. With fast processors, you can throw six cameras at it and not have a challenge,” Raciti says. He notes that cameras can now be triggered asynchronously instead of triggering them all at once, making it easier to get different views.

He predicts that this standard will take over, replacing alternative networks.  “From a cost and speed standpoint, Gbit Ethernet is the way to go. Firewire worked, but it’s overhyped. Gbit Ethernet is the wave of the future,” Raciti says. That will lower maintenance costs by extending the reach of Ethernet, which is used throughout many factories, and simplifying maintenance for technicians who no longer need to know multiple networking schemes.

Fast networks also make it simpler to attach displays that give operators insight into operations. Early vision systems often eschewed displays, but as the costs of compact LCDs has come down, more users want to see images, many integrators say.

For more information, search keywords “machine vision” at www.automationworld.com.