ECCO / ECCO+
Extended Camera Link Cable Operation
At a glance
- ECCO: Allows for 30% longer cables, or reach 30% higher speed
- ECCO+: Double the maximum cable length, or achieve twice the speed
- Use less expensive cables
- Based on advanced signal equalization technologies to restore the signal integrity
Do you need Camera Link cables longer than 10 meters?
The ubiquitous Camera Link standard offers many advantages to machine vision solution providers. Today, its strongest advantages are the many Camera Link compliant components available, the robustness and the price. The limitation has been the cable length as some applications require more than 10 meters (or more than 6 meters, in case of 85MHz cameras) between the camera and the host computer in applications such as robotics, web inspection, and flat panel display inspection.
Going beyond 10 meters with Camera Link used to require expensive devices such as repeaters and fiber optics, but now there is a more cost effective option called ECCO. With ECCO you can go beyond the Camera Link specification while taking advantage of high bandwidth, stability, and predictability benefits of Camera Link.
What is ECCO?
ECCO means ‘Extended Camera Link Cable Operation’, and Euresys developed it to address the cable length problem. Capitalizing on over 20 years of developing frame grabbers Euresys added this innovative feature to the latest generation of Grablink frame grabbers: Grablink Full XR, Grablink Full, DualBase, Duo and Base. With ECCO, Euresys has achieved a level of performance that is unique for a Camera Link frame grabber. We have entirely redesigned the Camera Link input stage using the latest technologies.
How do ECCO and ECCO+ work?
Camera Link cables use a number of lanes to transfer data signals from the camera to the frame grabber. As cables are not perfect, the propagation times of the data signals may differ between the lanes. This difference is called “skew” and the longer the cable the higher the skew.
ECCO and ECCO+ use an skew compensation technique between the Camera Link data lanes and the clock that more accurately samples the data signals. With ECCO and ECCO+, Grablink frame grabbers are more tolerant to skew and support longer or lower quality Camera Link cables.
Furthermore, ECCO+ uses advanced signal equalization technologies to restore the signal integrity. Equalization is the process of adjusting the balance between frequency components within an electronic signal. Available on the Grablink Full XR only, ECCO+ further stretches the capabilities of the Camera Link standard.
Far beyond the Camera Link limits
ECCO and ECCO+ allow the Grablink boards to go far beyond the Camera Link limits in terms of cable length or speed performance using standard Camera Link cables and standard Camera Link cameras.
Depending on the clock frequency and the cable quality, which can drastically vary from one cable to another, ECCO allows the new Grablink boards to work with cable lengths of at least 30% in excess of those specified by the Camera Link standard as well as in excess of those acceptable by the other boards with a “conventional” implementation of the standard. Alternatively, ECCO allows to achieve 30% higher speed, or even simply allows to use lower-cost cables.
The increase in performance provided by ECCO dependents on which configuration of the standard is used, and it is possible to achieve even more than a 30% performance improvement when using Base and Medium Camera Link.
ECCO+, available on the Grablink Full XR, achieves impressive results and simply doubles the maximum cable length compared to the recommendation of the Camera Link standard.
A practical example
The Camera Link standard defines that with a sampling rate of 85MHz, the maximum cable length is 5.9 meters and the maximum skew allowed in the cable is 50ps/m. With a Grablink board using ECCO, the cable length can be extended from 5.9 meters to 10 meters, even if the total skew introduced by the cable is as high as 750ps (75ps/m). In other words, with a low-quality 10 meter Camera Link cable exhibiting a skew of 750ps (which is 50% more than the 50ps/m skew allowed for cables by the standard), the maximum clock frequency of 85MHz can be reached! All the more impressive given the fact that a “conventional” implementation is not likely to support cameras with a pixel clock frequency higher than 65MHz.
When using the Grablink Full XR with ECCO+, 85MHz cameras can be used with a cable as long as 14 meters!