Camera Link Steps Up to New Challenges
Until now, Camera Link has offered the highest performance of the available standards and generally exceeded market needs, but things are rapidly changing as we move toward the future.
Today, new complementary metal-oxide semiconductor (CMOS) sensors are continuously pushing the resolution and speed boundaries upwards. With products on the market capable of 2-megapixel resolution and 10-bit output at 300 frames per second, the resultant data rates can exceed 5.7 gigabytes per second (Gb/s) or 720 megabytes per second (Mb/s).
While Camera Link today can support data rates up to 6.1 Gb/s, this requires the use of two cables, potentially making such products more complicated to manage in real-world environments. The single-cable base configuration of Camera Link can handle up to 2 Gb/s, but many products are already pushing past this rate and will soon require a more complicated two-cable solution.
The serdes components chosen are available at low cost from multiple vendors as discrete chipsets or as IP code that may be embedded into popular field-programmable gate arrays (FPGA) from vendors such as Xilinx or Altera.
The use of K-code technology allows signals dependant on low latency, such as trigger and GPIO commands, to be prioritized at a high level and packaged into smaller packets, which are then sent immediately between larger data packets. Though the signaling packets are sent at a higher priority than data packets, the system is robust and has bandwidth enough to maintain the data transfer in low latency synchronization with the source device (camera).
Since one of the fundamental purposes of Camera Link HS is to connect cameras producing video data up to 48 Gb/s, and because in the machine vision market it is presumable that the operator needs to be able to do real-time processing on each image, data forwarding to allow parallel processing is fundamental to many potential applications and is a key differentiator from other vision protocols.
- Interconnection between Camera Link HS components is possible with off-the-shelf copper and fiber optic solutions.
- Key to the Camera Link HS concept is the IP core.
- Data forwarding to allow parallel processing is fundamental to many potential applications and is a key differentiator from other vision protocols.