Sensoray 609 - Manual (Page 5)

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Introduction
Model 609 combines the functions of a 16x8 crosspoint video switch and a frame grabber. It is
based on the Conexant PCI video decoder FUSION878A. The software for the 609 is similar to the
SX11 software that supports a line of Sensoray image capture boards.
Feature Summary
§ PCI form factor (32 bit, 33 MHz PCI bus)
§ 16 video inputs (flat cable connector), 75 Ohm termination
§ 8 video outputs with programmable serial 75 Ohm termination allowing parallel connection of
multiple boards
§ multichannel frame grabber: allows image capture from 4 out of 8 selected output video
channels
§ supported video standards: NTSC-M, NTSC-Japan, PAL-B, PAL-D, PAL-G, PAL-H, PAL-I, PAL-M,
PAL-N, SECAM, CCIR, RS-170
§ PCI bus mastering: low CPU involvement during image capture
§ 16-bit input and 16-bit output general purpose I/O ports
§ Drivers and a DLL for Windows98/NT/2000
General Description
Model 609 has 16 video inputs (1 through 16), which accept standard composite video signal. Each
input is terminated with a 75 Ohm resistor.
The video outputs (0 through 7) have a series 75 Ohm termination resistor. With a 75 Ohm
termination at the receiving end the video switch provides a gain of 1. The programmable switch in
the output signal path allows connecting multiple outputs together without disturbing the
termination conditions. The termination switch is closed by default after power up.
The outputs 0 through 3 of the crosspoint switch are also connected to 4 multiplexed inputs of the
frame grabber. The signal components is digitized with an 8-bit A/D converter. 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.
The following simplified diagram shows the path of the video signal.