Cameras feature miniature "Camera Link" connectors
Currently, the Mini D Ribbon MDR-26 from 3M Inter- connect Solutions (Austin, TX, USA; www.3M.com/interconnects/) is the only approved standard for connecting Camera Link-based cameras and frame grabbers.
Currently, the Mini D Ribbon MDR-26 from 3M Inter- connect Solutions (Austin, TX, USA; www.3M.com/interconnects/) is the only approved standard for connecting Camera Link-based cameras and frame grabbers. With dimensions of 1.46 × 0.37 in., however, the size of the connector limits both the number of Camera Link interfaces that can be placed on PMC add-in boards and the ability to reduce camera-housing size.
Because of this, for two years the Camera Link committee of the Automated Imaging Association (AIA; Ann Arbor, MI, USA; www.machinevisiononline.org) has debated introducing a smaller version of the Camera Link connector. At this year’s Vision 2004 show in Stuttgart, Germany, the Camera Link committee once again met to discuss the future of the connector. As the committee sat in debate, one of its member companies-Sony Europe’s Image Sensing Solutions Division (Weybridge, UK; www.sonybiz.net/vision)-announced a range of “Camera Link-compatible” cameras that all feature a miniature “Camera Link” connector from 3M.
Featuring progressive scanning, frame rates from 15 to 60 frames/s, and resolutions up to 2 Mpixels, the XCL-V500 and X700 are VGA and XGA versions that measure 29 × 29 × 30 mm and weigh 55 g. Both the V500 and X700 models include internal/external sync, binning, and partial scanning and use a 1/3-in. progressive-scan interline-transfer CCD. For higher-resolution applications, Sony’s XCL-U1000 monochrome and XCL-U1000C color cameras offer 2-Mpixel resolution at 15 frames/s.
“What’s perhaps most upsetting,” said one attendee, “is that the connector used by Sony has not been officially endorsed by the AIA or the Camera Link committee, and Sony, therefore, has no right to claim that it is Camera Link compatible.” While other committee members expressed their feelings more vehemently, one admitted that Sony’s cameras were electrically compatible with Camera Link, and when the AIA did finalize on a miniature connector standard, Sony would have every right to claim compatibility.
Tentatively dubbed “”Mini-CL,” this connector is likely to be finalized at next September’s International Robots and Vision Show in Chicago, IL, USA. Bud Brown, general manager of Intercon1 (Baxter, MN, USA; www.nortechsys.com/intercon), provided overmolded connector samples to members in attendance at Stuttgart. According to Brown, Intercon1 was “just days away” from production in China.
Camera vendor CIS (Tokyo, Japan; www.ciscorp.co.jp) was also present and showed a prototype VGA camera that incorporated a miniature Camera Link connector that included power-delivery capability. Speaking on behalf of Fumio Nagumo, the director of the technical department at CIS, was Camera Link committee chair Steve Kinney, product manager with JAI Pulnix (Sunnyvale, CA, USA; www.jaipulnix.com). “While CIS has made no change in the transmission pin assignment,” Kinney explained, “the company has taken two of the four camera-control lines and used them to deliver power across the Camera Link connector.”
Many agreed that this was a good idea, but using this approach would mandate modifying the connector to stop such connectors from being interfaced to current Camera Link connectors. “From a frame-grabber manufacturer’s perspective, however,” said Andrew Buglass of Active Silicon (Uxbridge, UK; www. activesilicon.co.uk), “this will lead to a lot of different products, placing an increased burden on companies such as ourselves.”
Perhaps a better power-over-Camera-Link connector was proposed by JAI Pulnix’s Kinney. “If two inner grounds were used to transfer 5-V power,” he said, “there would be no need to redesign the connector and the chances of electrical damage would be minimized.”
Most members of the committee realized that this would possibly be a better solution than reassigning camera-control lines to deliver power over the connector. In concluding the meeting, Kinney suggested that perhaps when the Mini-CL connector was standardized, the adoption of a power-over-Camera-Link standard could also be incorporated. If this should happen, Sony may have to rethink the meaning of Mini-CL compatibility. Many of these subjects will again be discussed at the next meeting of the committee, to be held at the Vision Show West in May 2005 in Santa Clara, CA, USA.