Extron electronics System 5cr User Manual page 36

Reference • Appendix B
Glossary of terms
AC Reset –
Attenuation –
Audio follow –
Balanced Audio –
Bandwidth –
Breakaway –
Buffer –
Chroma –
Chroma Signal –
Clip, Clipping –
Composite Sync –
Composite Video –
Differential Audio –
Headroom –
High Impedance
IR Learning –
B-3
Following is a list of terms taken from Extron's Glossary.
Refers to status that changes when power is removed from a device. Many
electronic devices have live power inside, even after "Power off" has been
initiated from a panel or remote control device. This is not the same as "AC
Reset", when power is removed at the AC cord.
The decrease in magnitude (of a signal).
A term used when audio is tied to other signals, such as video, and they are
switched together. (The opposite of Breakaway)
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 differential audio.
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.
The ability to separate signals for the purpose of switching them independently.
For example: an audio and video signal from the same source may be "broken
away" and switched to different destinations. The opposite of the term "follow".
Generally referred to as a unity gain amplifier used to isolate the signal source
from the load. This is for both digital and analog signals.
The color information (hue and saturation), independent of luma intensity. Black,
gray, and white objects do not have chroma characteristics.
Part of a television signal containing the color information. Abbreviated as "C".
The level at which a signal excursion begins to exceed limits of the circuit and
flattens out, distorting the signal. When setting audio attenuation, the clip level
can be defined as a level short of the distortion point, thus allowing "headroom"
and maintaining the signal's fidelity.
A signal consisting of horizontal sync pulses, vertical sync pulses, and equalizing
pulses only, with no signal reference level. Also referred to as RGBS.
A combined signal which includes luma black and white, chroma (color), blanking
See Balanced Audio.
DLP –
Digital Light Processing – Also DMD (Digital Micro-mirror Device). Uses an array
of mirrors that move independently, reflecting light to compose the picture.
Gain –
A term used to denote an increase in signal power or voltage produced by an
amplifier in transmitting a signal from one point to another. The amount of gain is
usually expressed in decibels above a reference level. Opposite of Attenuation.
The margin between a nominal operating signal level and peak clipping
(distortion) level. See Clipping.
(Hi Z/High Z) – This is typically 10k ohms or greater. In video, when the signal is
not terminated locally, there may be a switch for Hi Z or some termination value
(75 ohms). Hi Z is used if termination is provided by another device.
The ability of a device to receive and store infrared commands for other devices,
such as the projector. With Extron's System 5, each command is assigned to a
system operation (such as selecting an input). When an operation is executed,
Extron • System 5 cr Switcher • User's Manual