Sensoray Model 311 frame grabber converts video camera signals into digital data required for computer image processing and display. Up to four cameras may be connected to the board: four with composite video or three with composite and one with an S-video input. The 311 provides four digital input lines and four output lines to control camera focus, pan, tilt and triggering.

Frame Rate
Model 311 can transfer 30 frames per second with the supplied software. It supports a variety of digital formats including RGB24 and Y8 that are directly compatible with Windows bitmaps.

Synchronization
The Model 311 uses special circuitry to achieve horizontal and subcarrier synchronization to incoming video. It guarantees generation of the required pixel/line from a video source in which line length can vary by several microseconds. This circuitry allows the 311 adapter to quickly and accurately lock on to video signals, regardless of source. Since the technique is completely digital, the 311 can recognize unstable signals caused by VCR head switching and adapt the locking mechanism to accommodate the source.

Image scaling
Under software control the 311 adapter can independently scale the X and Y dimensions of the captured frame. Full-resolution video may be reduced to any size down to the size of an icon. A software selectable digital filter is available to minimize aliasing artifacts induced by scaling.

A/D Conversion
The 311’s signal processor uses two flash analog-to-digital converters; one for chrominance and one for luminance. Each A/D provides 2x over sampling of the camera signal. Over sampling, combined with analog anti-aliasing filters, significantly reduces the overall sensitivity to unwanted aliasing signals and enhances the 311’s digital filtering.

The 311 is capable of sending just the luminance data to the host’s image buffer. This feature speeds capturing monochrome images.

Application Notes
Pixel Jitter in Frame Grabbers |  Frame Grabbers: FIFO vs. Memory Buffered

Software and Manuals

The software development kit, SDK, includes a C-language sample program that allows capturing and saving color and monochrome images. It illustrates the 311's scaling feature and shows how to call the included DLL from a C program. The supplied 32-bit DLL supports interrupts and multiple DMA buffers that may be scattered within the host's memory. The DLL supports capture directly into video memory and graphic overlays when using Direct Draw (only supported with enhanced SDK).

An enhanced development kit, SDK11E, includes more sample applications. It supports Direct Draw and the ability to store a color and monochrome image. SDK11E is sold separately for $ 95.

Compatible PC/104+ SBCs

Specifications

Images and Mechanical Drawings

Prices