Operating instructions

CHAPTER 2 TECHNICALLY SPEAKING

is through cables, the cables play the most important role. Poor quality cables can reduce the distance good

video can travel.

When a KVM switch is added to the equation, degradation of video quality is almost inevitable, especially

because few switch manufacturers are willing to take the costly and painstaking measures needed to keep the

video signal in optimal condition. NTI minimizes video degradation in the switch in two ways:

 We invest in high-quality, fast amplifiers and crosspoint solid-state switches.

 We engineer the design of the PCB to minimize noise and crosstalk.

Cable Quality

Cables carry the signal for much of the journey and significantly affect the final video output. Video signals

can travel further on high-quality cables than on poor-quality cables, which can cause ghosting and other

video anomalies.

The cables that NTI supplies with its KVM switch product line are the highest quality available on the

market today. This regard for high quality standard cables ensures that your video output not only meets but

also exceeds your expectations.

NTI’s cable distance guide (see Appendix A) will help you determine the cable length you can use for the

bandwidth your configuration requires.

Minimizing Noise

A more difficult challenge in engineering the video board and cables is minimizing “noise” and cross talk.

Engineers must lay out the copper trails that the signals travel on so that they do not interfere with each

other or pick up extraneous “noise” from other components both inside and outside the switch console. The

copper line cannot be close to other components or other pieces of the copper.

A highly skilled technician or engineer has to lay out the copper trails that the signals travel on so that they

don’t interfere with each other, or pick up extraneous “noise” from other components both inside and

outside the switchbox. They must then correlate all the board components so that the final signal strength

matches the capacity of the cables, ensuring that high-resolution images can travel to the monitor as clearly

and sharply as the original generated at the computer. NTI accomplishes this in several ways:

Stripline Technology

NTI uses stripline technology to reduce the possibility of noise from the cables. Stripline technology

provides a buffer that isolates signals from the rest of the cable data. Each signal travels independently from

all other signals, which ensures high quality output. NTI, using this stripline technology, thus provides the

widest available bandwidth to eliminate noise: 300MHz.

Impedance Matching

NTI also uses impedance matching to avoid video noise and signal degradation. Impedance matching

ensures that the output signal is the same as the input signal, even over long cables. Generally, longer cables

without quality control measures result in poor output quality. The distance the signal must travel greatly

affects the quality, especially if the data rate is high. While the signal is adequate over short distances, say 5

to 10 feet, any longer distance increases the degradation of a signal.

Impedance, or Ohms, is a cable characteristic defined by its construction dimensions and materials. An

impedance mismatch will cause reflections to occur while the signal is propogating down its electrical path.

These signal reflections will appear as ghosted images on the display monitor.

NTI uses cables with impedance matching to ensure that all NTI products maintain bandwidth purity – the

signal that goes in the cable leaves the cable in the same high quality manner as the input signal.