Overview
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serial port or another device that uses a similar communication protocol.
The simplest connection between the RS-232 controller and the controlled
device uses two wires (TRANSMIT, RECEIVE) and a common ground wire.
Adding inputs, outputs or both may extend a matrix switcher. In order to add
OUTPUTS to a matrix setup, a second switcher is added, and the inputs of
both matrices are connected in parallel (while assuring proper input
termination and avoiding double termination).
In order to add INPUTS to an existing matrix, a second machine is connected
- paralleling the outputs of both machines. When a matrix is to be extended in
both directions, both INPUTS and OUTPUTS are paralleled using four or
more machines. A matrix can be extended only if it is designed as an
extendable matrix, e.g., inputs should be looping and outputs should be able
to be internally disconnected or become “floating”.
There are many factors affecting quality when signals are transmitted from a
source to an acceptor:
•
Source and acceptor signal handling capability - different brands offer
different quality and the final result is determined by the performance of the
lowest quality part. Using a low quality source will always result in low
quality duplicates
•
The connection cables should be of the best possible quality. Low quality
cables are susceptible to interference, deteriorate signal quality due to poor
matching and cause elevated noise levels
•
Sockets and connectors of the sources and acceptors - so often ignored,
should be of best quality, as "Zero Ohm" connection resistance should be
assured. Sockets and connectors should match the required impedance (75
ohms in video). Cheap connectors tend to rust, causing breaks in the signal
path
•
Amplifying circuitry quality is extremely important and is needed for
high linearity, low distortion and low noise operation
•
The distance between source and acceptors plays a major role in the final
result. If there are long distances (over 15 meters) between sources and
acceptors, special means should be taken in order to avoid cable loss, such as
using higher quality cables or, if necessary, adding line amplifiers
•
Interference from neighboring appliances may have an adverse effect on
signal quality. Balanced audio lines are less prone to interference, but
unbalanced audio and video lines should be installed far away from mains
carrying cables, electric motors, transmitters etc., even when cables are
shielded
