Black Box ACS251A - Manual (Page 14)

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CHAPTER 3: Compatibility and Signal Processing
3. Compatibility and
Signal Processing
This chapter discusses technical details of how the ServSwitch™ Brand Fiber KVM
Extender II and II-SM process I/O signals, and how that processing affects
compatibility with various equipment.
3.1 Video Processing
The Extender’s Local Unit contains powerful electronics to process your video
signal with superior quality. Video input is digitized as 16-bit data (65,536 colors).
The Local Unit can accept these resolutions and vertical refresh rates (though the
refresh rate output by the Remote Unit is always 60, 75, or 85 Hz):
• DOS mode at 640 x 400, 720 x 400, 640 x 350, or 720 x 350 at up to 85 Hz
• VGA 640 x 480 at up to 85 Hz
• SVGA 800 x 600 at up to 85 Hz
• XGA 1024 x 768 at up to 75 Hz
• VGA-compatible 1152 x 864 at up to 75 Hz
• SXGA 1280x1024 at up to 72 Hz
It also accepts these synchronization options (though the Remote Unit always
outputs separate horizontal and vertical sync):
• Separate horizontal and vertical sync (RGBHV), common on PCs.
• Composite sync on the horizontal sync line (RGBS), used in some older
machine-control systems.
• Composite sync overlaid on the green color signal (RGsB, “sync on green”),
common on many UNIX workstations.
Almost all non-DDC signals that might be received from the attached computer
CPU at the “CPU Video” connector are passed through to the “Local Video”
connector for the optional local monitor. These signals are buffered internally for
better signal integrity.
The brightness and contrast of the video signal are adjusted automatically before
digitizing the signal. This ensures the best possible video quality without requiring
configuration or adjustment by the user.