Almost written-off by the introduction of new technology, the venerable frame grabber is alive and well. Here we look at some of the major players.
Michael Yampolsky, CEO of KAYA Instruments, explains how CoaXPress 2.0 offers new opportunities for system designers.
“In 2011, the Japan Industrial Imaging Association (Tokyo, Japan, http://jiia.org) ratified Version 1 of the CoaXPress (CXP) standard, a standard that eventually replaced the older Camera Link Standard developed by the Automated Imaging Association (AIA; Ann Arbor, MI, USA; www.visiononline.org).
“Perhaps the main reason for this was the need for speed. Even in it’s fastest Extended Full or Deca Mode, the Camera Link standard was only capable of data transfers of 6.8Gbits/s (850 Mbytes/s). Unlike Camera Link, the CXP standard is scalable both in the number of channels used and the speeds at which they can operate. These include CXP-1 links that can transfer data over co-axial cable at 1.25 Gbit’s to distances of up to 212 m, CXP-2 links running at 2.5 Gbit/s, to distances of 185 m through to the fastest CXP-6 links running data at 6.25 Gbit to 68 m.
“To meet the demands of systems integrators KAYA Instruments introduced a range of CoaXPress-based PCIE products known as the Komodo 8CH CoaXPress frame grabber series. These are offered in a number of configurations with one, two, four or eight CXP-6 – 1, 2, 4, 8 channel configurations on PCIe Gen3 x8 interface cards. By offering such a range of interfaces, the developer can then choose which frame grabber is required, without paying for an excessive number of links.
“Several other major benefits of the original standard were using low-cost coaxial cable with a standard 75 Ω BNC connectors. As well as the maximum CXP-6 speed, Version l of the standard also sports a serial 20.83Mbps frame grabber-to-camera uplink channel to allow for fast camera control. And, like Camera Link, the CXP interface also supports 13W Power over CXP (poCX), camera triggering and camera control.
This year, the JIIA introduced the latest version of the CoaXPress standard Version 2. This supports data links as fast as CXP-10 (10 Gbps) and CXP-12 (12.5Gbps), with the benefit that developers can reduce systems cost by choosing cameras with fewer camera-to -computer links. In Revision 2, a hybrid cable connection with High-Density BNC or DIN 1.2/2.3 connectors are used to interface cameras to frame grabbers. Here again, camera vendors are introducing a range of frame grabbers with different numbers of links to meet a variety of applications. The first two from KAYA Instruments, for example, will be the Predator II single channel CXP-12G frame grabber (Figure 3) and the four channel Komodo II CoaXPress 12G Frame Grabber.
“While the CoaXPress Version 2 standard represents a breakthrough in terms of speed, it, like the Camera Link standard before it, will become camera-to-computer distance limited as speeds increase. Recognizing this, both the JIAA and independent hardware companies are debating the future of high-speed interfaces. What seems to be emerging is that, perhaps in five years, fiber interfaces will more than likely be the interface of choice. Indeed, companies such as KAYA Instruments have already introduced products such as the Komodo FXP CoaXPress over Fiber acquisition system that allows up to eight CoaXPress (CXP-6) channels to be interfaced to cameras as far as 80km distances from the frame grabber.