User`s manual

Piranha HS 4x User’s Manual 47
DALSA Corp. PRELIMINARY 03-32-10040-03
Appendix A
Camera Link™ Reference and
Configuration Table
Camera Link is a communication interface for vision applications.
For years, the scientific and industrial digital video market has lacked a standard method
of communication. Both framegrabber and camera manufacturers developed products
with different connectors, making cable production difficult for manufacturers and very
confusing for consumers. Increasingly diverse cameras and advanced signal and data
transmissions have made a connectivity standard like Camera Link a necessity.
LVDS Technical Description
Low Voltage Differential Signaling (LVDS) is a high-speed, low-power general purpose
interface standard. The standard, known as ANSI/TIA/EIA-644, was approved in March
1996. LVDS uses differential signaling, with a nominal signal swing of 350mV differential.
The low signal swing decreases rise and fall times to achieve a theoretical maximum
transmission rate of 1.923 Gbps into a loss-less medium. The low signal swing also means
that the standard is not dependent on a particular supply voltage. LVDS uses current-
mode drivers, which limit power consumption. The differential signals are immune to ±1
V common volt noise. Camera Link uses an implementation of LVDS technology called
Channel Link®.
Camera Signal Requirements
This section provides definitions for the signals used in the Camera Link interface. The
standard Camera Link cable provides camera control signals, serial communication, and
video data.
Video Data
The Channel Link technology is integral to the transmission of video data. Image data and
image enable signals are transmitted on the Channel Link bus. Four enable signals are
defined as:
• FVAL—Frame Valid (FVAL) is defined LOW for valid lines.
• LVAL—Line Valid (LVAL) is defined HIGH for valid pixels.
• DVAL—Data Valid (DVAL) is defined HIGH when data is valid.
• Spare— A spare has been defined for future use.
All four enable signals must be provided by the camera on each Channel Link chip. All
unused data bits must be tied to a known value by the camera. For more information on