Frame grabbers

A frame grabber is dedicated image capture hardware for a PC. It receives camera data and, depending on the model, can take on additional tasks: trigger encoder camera control lighting synchronization DMA FPGA processing

Typically with: CoaXPress Camera Link certain high-speed systems complex line scan systems high-precision trigger and encoder control With normal GigE Vision or USB3 Vision systems, a classic frame grabber is not usually required.

A network card is a general Ethernet interface. A frame grabber is developed specifically for image capture and industrial camera control. With GigE Vision the network card normally handles the data transfer; CoaXPress, by contrast, needs suitable specialized hardware.

Many industrial frame grabbers can generate, distribute and delay triggers. That is a product property, however, and is not identical on every frame grabber.

Many line scan frame grabbers support quadrature encoders. The line rate can thereby be coupled directly to the real movement.

Many professional frame grabbers provide strobe or digital output signals for synchronizing the lighting. In fast line scan applications this allows every light pulse to be synchronized precisely with one line, for example.

DMA stands for direct memory access. Capture hardware can transfer data straight into system memory without the CPU having to copy every data word individually. Euresys uses DMA for on-the-fly line scan stitching without an additional CPU copy operation, for example.

An FPGA is programmable hardware logic. Frame grabbers can use it to carry out certain processing steps during image capture itself. That can reduce CPU load and data volume and allow very deterministic processing.