Operating instructions

CHAPTER 1 SIMPLY PUT
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designed to translate (seamlessly emulate) all variations of the different devices, including specialized
devices such as the Microsoft Intellimouse®.
• Video switching is more complicated. KVM switches, unlike video cards or monitors, do not have a hard
resolution limit that prevents them from handling anything higher than some particular resolution and
refresh rate. The switch simply sees an analog signal and passes it through. Signals with a higher resolution
and refresh rate require greater bandwidth. If the bandwidth requirements exceed the capabilities of the
cables, connectors or switching components inside the KVM switch, the picture can get fuzzy and distorted.
Impedance mismatching issues can cause ghosting at higher resolutions. The resultant image on the monitor
can become poor and degraded.
To ensure there is clean, clear video output, better switches terminate the video output of all the non-
selected computers and actively buffer the selected one. This avoids poor imaging, ghost images, and other
video anomalies. Users get a clear image with no ghosting or fuzziness.
In multiple platform KVM switches, internal circuitry also converts between the different video formats,
depending on the selected computer.
While the information here has been greatly simplified, it may be sufficient to understand that KVM
switches:
1) Take signals to and fro the computer, keyboards, mice, video cards and monitors.
2) Translate (convert) the signals as necessary.
3) Output the correct data according to the selected computer’s platform.
• Expansion, Upgrade & Reconfiguration capability – the ability to integrate additional KVM switches and
computers into a growing network, and to be able to transparently mix different hardware and software
platforms, is critical for many applications.
• Today’s computers increasingly utilize USB-standard peripheral ports. KVM switch configurations must be
capable of:
 Integrating USB-enabled computers with legacy (PS/2 style) computers.
 Booting up all attached USB-enabled computers (PCs and Macs) simultaneously.
 Present a sustained presence of keyboard and mouse to USB-enabled computers.
• Extending control to the user rather than requiring the user to travel to the control console. With computer
networks expanding, extending control over a distance becomes more important. Utilizing a KVM switch
configuration with cables and adapters can extend the control console (keyboard, monitor and mouse) to the
user’s workspace, rather than requiring the user to travel to the computer server room, frees up staff time to
be used more productively.
• As computer networks expand, flexible methods of controlling the KVM switch become more important.
While simple rotary knobs, front-panel buttons and keyboard commands may be sufficient for controlling
only a few computers, larger applications benefit from an array of control options including liquid crystal
display, RS232 control, infrared wireless remote, and on-screen control (OSD) menus.
SECURITY
• Security is an important concern today. Some switch manufacturers, such as NTI, provide security features
that provide an additional layer of security in the work environment. One such feature is authorized access,
which allows the network administrator to assign password protection and limit user access to servers
attached to the KVM switch. Another method is keylock access, in which users must use a key that fits into
the switch before the switch will allow controls to be operated.