Coaxpress and Camera Link HS emerged
after the unsuccessful attempt on VISILink. The event unfolds by these two
digital interfaces in industrial cameras draw parallels to the iconic video format
war in the consumer market. In the 70s we have VHS verse Betamax and in the
recent millennium, HD-DVD verses Blue-Ray. If there is anything to learn from
history, neither the best nor the cheapest technology will emerge as the
victor.
Of the most lucrative and largest
volume in the high bandwidth industrial digital camera is the sales of linescan
cameras. In linescan applications there is endless request for higher line speed
and larger data bandwidth, this poses a challenge to the existing bandwidth of CameraLink
standard as sensor technology advanced. The demand for a new high speed
digital interface arises.
Dalsa with its linescan solution has
precipitated a formidable wall in the industry. Dalsa not only actively seek for
available technology but also invested heavily on prototypes. With opportunity
arises during the flat panel and LEDs era in the mid 2000s, Dalsa announced its
solution to serve the market request, HS-Link together with Piranha HS 12K TDI
camera in 2009. Thereafter, they take this development to AIA to adopt it as
Camera Link HS.
Coaxpress is originally developed by
five companies and anointed by JIIA. With many anxious to jump onto the high
speed wagon, Coaxpress is now being supported by many cameras and framegrabber
card vendors. Among them, e2v and Active Silicon presented an attractive
alternative to Dalsa Camera Link HS 16k linescan solution (ELiiA 16k linescan
camera with FireBird framegrabber card). Compared to Dalsa monochromic domination
in Camera Link HS, the Coaxpress technology appears to fill with genetic
diversity and vibrancy.
From the technological perspective,
Coaxpress uses EqcoLogic
transceiver while Camera Link HS leverages on 8b/10b Gigabit Ethernet
technology.
Camera Link HS
|
CoaXpress
|
Camera Link
|
||
Bandwidth
|
6000MB/s
|
12000MB/s
|
850MB/s
|
|
Trigger
|
3.2ns Jitter
|
12ns Jitter
|
0 ns Jitter
|
|
Distance
|
15m on CX4
|
100m
|
10m
|
|
Com Channel
|
300MB/s
|
2.1MB/s
|
1MB/s
|
|
Integrated into FPGA
|
Yes
|
No*
|
Yes
|
*Today there is an untested alternative from kaya instrument
With bandwidth double of Camera Link HS and superior running
distance, at a single glance, CoaXpress looks set to replace Camera Link HS.
However, the winner of the consumer video format war has taught us that
superior technological and lower price does not guarantee success. Camera Link
HS have some very distinctive advantages, Dalsa has been dominating the high
end linescan (TDI) market for years, there is already a very well established
integrated Dalsa camera and framegrabber solution and by exploiting network
technology (8b/10b) there is a possibility of cheaper solution in the near
future by third party framegrabber cards.
There is third
party framegrabber card vendor pledging support on
Camera Link HS under the IAI flag and evidence of any serious challenges
against Dalsa linescan domination at this moment is still exiguous.
The die has been cast and the clash between the two standards in the linescan arena is inevitable. The cameras technology available from either side will act as
the hammer whiles the interface standard as the anvil. A new chapter for
linescan inspection will be forged with higher line speed and higher sensor resolution.