CoaXPress is a digital interface standard that allows the transmission of data from a device, for example a camera, to a host such as a frame grabber in a PC, at a high speed of up to 6.25 Gbps over a single coax cable. There are many improvements to an imaging system that CoaXPress can unlock – here are a few:
- Go to greater resolutions at the same or greater frame speed (for example 12 Megapixels at 187 fps)
The most advanced CMOS global shutter image sensors are enabling impressive frame rates such as the CMOSIS 12 Megapixel CMV12000 which offers 4096 x 3072 pixels at 187 frames per second (fps). With the CoaXPress bandwidth of 6.25 Gbps per cable, the data rates of 12 Megapixels at 187 fps are supported with 4 cables.
Or, 25 Megapixels is limited to about 30 fps over Camera Link and with the latest generation image sensors can reach 80 fps via CoaXPress. These ultra high resolution cameras also offer many resolution options using Region of Interest, such as 16 Megapixels at over 100 fps.
- Get access to 10 bits rather than 8 bits (increase in bit depth at maximum sensor speed)
The bit depth or dynamic range is also influenced by the bandwidth of the interface. The accuracy of the measurement can be improved with more bits. Because of the large bandwidth with CoaXPress, more bits can be provided without reducing the frame speed to have improved measurement capability without reducing throughput.
- Reduce power consumption
Besides increased bandwidth, CoaXPress can have even lower power consumption than Camera Link at twice the frame rate. First CoaXPress camera designs were power hungry. With next generation designs and latest FPGAs, 25 Megapixel cameras at full frame rates can be only 8W of power consumption with no fan required. This does depend on the implementation and some ultra high resolution CoaXPress cameras still have a large power consumption (up to 28W) so be sure to check the specifications.
- Allow for easy upgrades to even greater resolutions in the future (clear roadmap)
In 5 years, typical data rates will be double for many applications and the next generation of CoaXPress will offer 12.5 Gbps per cable to support this. With a clear and supported roadmap, system designers can be assured that if they design CoaXPress in now, they can upgrade the other components of their system as they need to for the next 10 years at least without needing to make the costlier investment of changing interfaces.
The well-defined CoaXPress roadmap also encourages more component suppliers to create products. The options will continue to expand.
- Reduce the number of cables
CoaXPress is the only interface that offers video, camera control and power over a long, flexible cable. All other interfaces have a trade-off. With the increased bandwidth per cable and the power included over the cable, the number of the cables and the system complexity is greatly reduced.
- Increased cable lengths between the imaging system head and the processing system
Longer cable lengths can support several design advantages such as in machine vison, it eases the design with moving measurement heads or keeps heat of the PC away from measurement system. With global security, long cable lengths and flexible cables allow for routing throughout vehicles and use with slip rings. With medical applications, it can enable new innovative technologies such as endoscopes.
- Multiple camera systems are simplified
CoaXPress (CXP) is an ideal interface for linking together data from several cameras since CoaXPress has the ability to carry many channels of image data and meta-data, which makes the interface easily scalable.
Because multiple cameras can be linked via a single frame grabber and long, low cost coaxial cables and with absolute synchronization, an accurate system can be created. For example, four (4) 8 Megapixel cameras at 16 fps each can be combined on a single frame grabber with a single cable per camera with power also over the cable greatly reducing the system complexity.
CoaXPress as an interface for multiple camera solutions in machine vision provides system builders the highest throughput improvement options. In addition, greater flexibility is available as different non-similar cameras with varying speeds can be connected with the same PC/frame grabber architecture without any constraints in cable lengths and with low cabling costs.