Ocean Matrix OMX-9040, Manual

OMX-9040 

3x1 Video Switcher 

Several words on Video/Audio Switchers:   

A video/audio switcher usually switches between several sources and 

one or more acceptors. A switcher that allows several inputs to be connected 
to several outputs simultaneously is called a matrix switcher. Switchers may 
be of the electronic or mechanic type. Most matrices are of the active 
electronic type, with many crosspoints. 
Vertical Interval Switching, often used in video, assures that the transition 
from one video source to the other (like switching between two Genlocked 
cameras) is smooth and without interference. The switching and changeover 
is done during the blanked vertical interval period, where the transition is 
hidden from the eyes. 
Vertical Interval switching is needed when recording or transmitting a video 
program involving several video sources, as in live broadcast, to assure 
"clean", undisturbed picture transitions. The switched sources should be 
genlocked. Matrices and switchers may be RS-232 controlled. RS-232 
control is a way of remotely controlling a video or audio device (Switcher, 
SEG etc.) using a personal computer with a 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. 

Equipment Cables And Solutions 

Video recording and playback frequently involve the use of several 

devices, such as: Video Cassette Recorders, Video Disc Players. Cameras, 
Video monitors, Video processors, Special Effects Generators, Live or 
Satellite Feeds or any combination of the above.