Extron Electronics Matrix 200 - Manual (Page 76)

Extron • Matrix 200 • User’s Manual
Appendix A • Part Numbers, Glossary and Troubleshooting
Glossary of terms
AC – Alternating Current –
Flow of electrons that changes direction alternately.
ADA – Analog Distribution Amplifier – A device that takes in one signal and distributes it
to several outputs without “tying” those outputs together (buffered).
Adapter – A linking device which allows two dissimilar devices to connect physically, and/or
communicate electronically.
AMPS – (Amperes) A unit of measurement for current.
Analog (Analogue) – A continuous action, or movement that takes time to change from one position to
another. Standard audio and video signals are analog. An analog signal has an
infinite number of levels between its highest and lowest value. (Not like digital,
where changes are by steps.)
ANSI – American National Standards Institute
ASCII – American Standard Code for Information Interchange. The standard code
consisting of 7-bit coded characters (8 bits including parity check), utilized to
exchange information between data processing systems, data communication
systems, and associated equipment. The ASCII set contains control characters
and graphic characters.
Aspect Ratio – The relationship of the horizontal dimension to the vertical dimension of a
rectangle. In viewing screens, standard TV is 4:3, or 1.33:1; HDTV is 16:9, or
1.78:1. Sometimes the “:1” is implicit, making TV = 1.33 and HDTV = 1.78.
Attenuation – The decrease in magnitude (of a signal).
Audio Follow – A term used when audio is tied to other signals, such as video, and they are
switched together. (The opposite of Breakaway)
Balanced Audio – A method that uses three conductors for one audio signal. They are plus (+),
minus (-) and ground. The ground conductor is strictly for shielding, and does not
carry any signal. Also called Differential Audio.
Bandwidth – A frequency range, or “band” of frequencies, within which a device operates. In
audio and video, it is the band of frequencies that can pass through a device
without significant loss or distortion. The higher the bandwidth, the sharper the
picture; low bandwidth can cause a “fuzzy” picture.
Black Level – More commonly referred to as “brightness”, the Black Level is the level of light
produced on a video screen.
Blanking – The turning off of the electron beam that scans the image onto the screen. When
the beam completes a scan line it must return (retrace) back to the left. During
this time, the beam must be turned off (horizontal blanking). Similarly, when the
last line has been scanned at the bottom of the screen, the beam must return to
the upper left. This requires vertical blanking.
Blooming – Most noticeable at the edges of images on a CRT, “blooming” is when the light
hitting the screen phosphors is so intense that it overdrives them. The edges of
an image seem to exceed its boundaries. Thin lines and sharp edges may look
thick and fuzzy. This may be caused by the brightness being set too high, or by a
high voltage problem.
BNC – It is a cylindrical Bayonet Connector which operates with a twist-locking motion.
Two curved grooves in the collar of the male connector are aligned with two
projections on the outside of the female collar. This allows the connector to be
locked in place without the need of tools.
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