Sensoray 311 - Manual (Page 5)

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Introduction
The 311 PC104+ frame grabber allows the capture of monochrome and color images from a
variety of analog video sources into computer memory (RAM). The 311 is designed to work with
standard TV signal sources, compatible to the following video standards:
§ color: NTSC-M, NTSC-Japan, PAL-B, PAL-D, PAL-G, PAL-H, PAL-I, PAL-M, PAL-N, SECAM;
§ monochrome: CCIR, RS-170.
The 311 digitally locks to the incoming video signals providing a stable output regardless of the
signal source. The input’s 4:1 multiplexer allows the selection between four composite or three
composite and one Y/C (S-Video) analog video inputs, which makes it possible to connect up to
four video sources to the frame grabber. The signal components (luminance and chrominance)
are digitized with two separate 8-bit A/D converters. Low-pass filtering and double over-sampling
of the input signal provide precise digitization with no aliasing artifacts. The digital signal is then
scaled and/or cropped to the desired dimensions, if necessary. The scaled image is transferred to
the host RAM using the PCI bus mastering mode, which requires minimum CPU attention. An on-
board FIFO provides necessary buffering, minimizing the probability of image loss.
An 8-bit general purpose I/O port allows interfacing of the 311 to external hardware, which could
be used, for example, for triggered image acquisition.
System Requirements
The 311 is designed to work with 32-bit, 33 MHz, 5 V PC/104+ bus. An important system
requirement is fast PCI-to-DRAM transfer. Some PC/104+ CPU designs may not provide
bandwidth sufficient for image transfer, which may result in image corruption.