Nikon MRDI user manual Video Data Signals, Camera Control Signals, Communication

Video Data Signals

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:

FVAL-Frame Valid (FVAL) is defined HIGH for valid lines	(not used by the
	CAM/CMOS – 2K.LS).
LVAL-Line Valid (LVAL) is defined HIGH for valid pixels	(LineValid Output in the
CAM	CMOS – 2K.LS).
DVAL-Data Valid (DVAL) is defined HIGH when data is valid	(Always High in the
	CAM/CMOS – 2K.LS).
Spare- A spare has been defined for future use	(not used by the CAM/CMOS–
	2K.LS).

In the general specification, 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 image data bit allocations, refer to the official CameraLinkTM specification (http://www.machinevisiononline.org.).

Camera Control Signals

Four LVDS pairs are reserved for general-purpose camera control. They are defined as camera inputs and frame grabber outputs. Camera manufacturers can define these signals to meet their needs for a particular product. In the case of the Fairchild Imaging CAM/CMOS - 2K.LS, the signals are:

•	"ExSync" Line Synchonization Input	(generically Camera Control 1, CC1)
•	"ElectShutter" Exposure Control Input	(generically Camera Control 2, CC2)
•	Spare, unused	(generically Camera Control 3 ,CC3)
•	Spare, unused	(generically Camera Control 4, CC4)

Communication

Two LVDS pairs have been allocated for asynchronous serial communication to and from the camera and frame grabber. Cameras and frame grabbers should support at least 9600 baud. These signals are:

SerTFG	Differential pair serial communications to the frame grabber.
SerTC	Differential pair serial communications to the camera.

The serial interface will have the following characteristics: one start bit, one stop bit, no parity, and no handshaking. It is recommended that frame grabber manufacturers supply both a user interface and a software application programmming interface (API) for using the asynchronous serial communication port. The user interface will consist of a terminal program with minimal capabilities of sending and receiving a character string and sending a file of bytes. The software API will provide functions to enumerate boards and send or receive a character string.

Fairchild Imaging • CAM/CMOS-2K.LS Line Scan Camera User’s Manual • Rev A • 36 of 41