Camera Link

from Wikipedia, the free encyclopedia
A Base Camera Link configuration consists of 4 LVDS wire pairs and one pair for the clock.

Camera Link (CL) is an interface in industrial image processing . It is specified for fast image transfer. The standard is administered by the Automated Imaging Association (AIA).

properties

The bit width per pixel can vary between 8 and 16 bits. The maximum pixel frequency is 85 MHz. If more data is to be transmitted, this can be done in parallel streams, so-called taps.

Camera Link is available in three versions:

  • Base (maximum 24 bits per clock) - e.g. E.g .: 255 MB / s with 3 taps of 8 bits
  • Medium (maximum 48 bits per cycle)
  • Full (maximum 64 bits per cycle) - e.g. E.g .: 680 MB / s with 8 taps

An MDR-26 connector from 3M is defined as the connector. The wider range of medium and full specifications is implemented using a second connector / cable.

Both monochrome and color images can be transmitted.

Power over Camera Link was added to the Camera Link specification 1.2 . Cameras no longer need their own power supply.

Connection to the PC

A CL camera is connected to the PC using a CL cable, which must be equipped with a CL frame grabber . Several lines are available for communication from the PC to the camera. Two of them form a normal RS-232 UART interface. This is mainly used to configure and control the camera. Four further signals can be freely configured and are therefore camera-specific. In general, a trigger is sent to the camera via the first of these four lines in order to control it from outside (e.g. by a light barrier). This external triggering allows for a very low release delay ( latency ) of the camera.

The maximum cable length depends on the pixel clock; with full configuration, it is> 80 MHz, rarely more than 10 meters. If longer cables are required, the signal must be amplified at regular intervals.

history

The first version of Camera Link was released in 2000. Camera Link is based on National Semiconductor's Channel Link Protocol . Version 1.1 was released in January 2004.

The big innovation in version 1.2 is Power over Camera Link .

Individual evidence

  1. ↑ AIA - Vision Online - Camera Link. Retrieved May 25, 2013 .