-How to Select the Right Vision InterfaceThere are several video interface options currently available to connect various elements of imaging systems for machine vision, medial, outdoor and military applications. At the higher end of the performance range, standards such as Camera Link and GigE Vision have served their users well for the past decade, a period which ushered in an era of interface standardization in the industry. But new demands from systems makers, combined with improvements in camera performance and technical innovations in interface technology, are resulting in a second wave of high-speed connection options being developed. These include CoaxPress, Camera Link HS and 10 GigE Vision (GigE Vision over 10 GigE).
Given that cabling/connection media can account for up to 50% of a system’s upgrade costs, the physical interface is extremely important. When considering a move to one of the emerging high-performance options, system developers must carefully weigh the tradeoffs across a range of criteria, including cost (initial and long-term), speed, ease of implementation and use, power, supplier support, and physical connection requirements in order to choose the best connectivity alternative for their specific application.
Each interface offers a unique approach to addressing the range of challenges present in modern imaging systems:
- GigE Vision: Used in low- & mid-end vision systems with less critical speed and timing demands; cost effective solution when full speed is not required
- Camera Link: Industry default choice for higher speed connectivity where limited cable length and high cable costs are acceptable
- CoaXPress: A new standard for applications that require higher speeds, longer cable lengths, and a single, flexible and inexpensive cable; frame grabber still required; CoaXPress products are available from Adimec and many others now
- Camera Link HS: Originally designed to overcome the speed limitations of Camera Link for line scan cameras; first products may enter the market in 2012
- GigE Vision over 10 GigE: Built on GigE Vision, faster physical layer and better timing accuracy with much higher power consumption; requires server grade equipment for implementation
No more trade offs
Until recently, there were only 2 choices for demanding imaging applications: Camera Link for higher speeds but with short cable lengths or GigE Vision for longer cables but slower speeds. Essentially, a trade off always had to be made.
As a result, several initiatives are well underway that focus on improving camera interfaces to support the needed bandwidth, as well as provide cost-effective, scalable approaches. Each offer unique advantages and limitations. Developers of camera-dependent systems should evaluate their specific application requirements and understand the differences between the options available.
Important considerations -- beyond just raw performance -- are:
- Ability to easily integrate with existing system architecture
- Flexibility of the connection medium
- Scalability of solution to meet future requirements
- Physical infrastructure for application
- Transmission distance required
- Overall implementation cost
- Availability of products based on the interface
|FREE DOWNLOAD: Vision Interface Comparison|
|For a detailed comparison of the above interfaces, click the image to download a free white paper.|
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