CoaXPress-over-Fiber: The future of CoaXPress
What is CoaXPress-over-Fiber? CoaXPress-over-Fiber is a light but significant extension of the existing CoaXPress specification to support transport over fiber optics.
CoaXPress (CXP) is the de-facto standard for high-bandwidth computer vision applications. CoaXPress 2.0, the latest version of the specification, specifies the CXP-12 speed, a 12.5 Gbps (Gigabit per second) link over a coaxial copper cable. As link aggregation is common with CoaXPress, bandwidths of 50 Gbps (12.5 x 4) are easily achievable with four CXP-12 links.
CoaXPress-over-Fiber has been designed as an add-on to the CoaXPress 2.0 specification. It provides a way to run the CoaXPress protocol, as it is unmodified, over a standard Ethernet connection, including fiber optics. As such, CoaXPress-over-Fiber uses standard electronics, connectors and cables designed for Ethernet, but the protocol is CoaXPress, not Ethernet, not GigE Vision.
Euresys and Sensor to Image have started the development and demonstration of CoaXPressover-Fiber in 2018. The CoaXPress-over-Fiber specification has now been approved as an add-on to the CoaXPress 2.0 standard, which is hosted by the JIIA (Japan Industrial Imaging Association).
What are the advantages of using Ethernet connectivity? By using Ethernet connectivity, CoaXPress-over-Fiber benefits from the low-cost standard equipment (such as connectors and cables) designed for Ethernet. Ethernet is defined by IEEE 802.3 standards; by leveraging these standards, CoaXPress-over-Fiber will also benefit from the constant evolution of Ethernet towards higher bandwidths.
What are the pros and cons of using fiber optics?
Pros
• First and foremost, cable length is not an issue anymore as fiber connectivity is basically not limited in length
• Fiber optics provide more bandwidth, as connectivity at 10, 25 and 50 Gbps per fiber is standard today and widely used in data centers
• Fiber optics are immune to electrical noise, which is a significant advantage on the production floor in and some medical applications
• Fiber optics are lighter and smaller in size than the equivalent copper cabling, making it appropriate for applications where this characteristic is essential, like in aircraft or vehicles.
Cons
There is no power over fiber. As signals in fiber optics are transmitted using light, there is no way to transfer power over fiber optics and devices such as cameras must be powered separately.
