Camera Link feels growing pains

Based on reports from the recent International Robots & Vision show (June 3-5, Rosemont, IL), camera suppliers have faith in Camera Link as an interface standard. This year's attendees saw more and more products that comply with that standard. But the industry has outgrown the original specifications, which concentrated mainly on interface signals, cables, and connectors. Now, manufacturers must address communication incompatibilities between cameras and frame-grabber boards.Before the advent of the Camera Link standard, many manufacturers used a serial port to communicate instructions to their cameras. To accommodate those communications, the Camera Link specifications provided for serial communications, but they did not mandate a protocol, or format, for them. As a result, some incompatibilities exist between frame grabbers and the camera-control software supplied by camera manufacturers. These problems usually appear during the configuration and setup sequences that rely on serial communications from a host PC through a frame grabber to a camera.

The Automated Imaging Association (AIA), along with camera and frame-grabber manufacturers, continues its work to eliminate most of the compatibility problems. Currently, a subcommittee is circulating revisions to the Camera Link standard that will specify the protocol for the interoperation of cameras and frame grabbers and will establish tools to test the compatibility of products. The revised standard, scheduled for a vote this summer, also specifies an application program interface (API), essentially software function calls, that will ease the job of communicating over the Camera Link's serial lines.

An updated standard will simplify communications between Camera Link cameras and frame-grabber boards. Courtesy of Data Translation.

But vision-equipment buyers need not shy away from Camera Link. For now, they must ensure that they buy equipment that will work together in a vision system. Thankfully, manufacturers post product-compatibility information on their Web sites. (Always call them for the latest updates.)

Even with the adoption of a new standard, Camera Link proponents still have work ahead. They must address the standardization of formats for image-data transmission and the use of new connector types at the frame-grabber end of the link. Eventually, the standard will guarantee plug-and-play operation, but in the meantime, Camera Link—like most new standards—still has some growing up to do.

Jon Titus Contributing Technical Editor, jontitus@attbi.com