Extron Glossary of Terms
Twisted Pair


Additive color process - Also called “RGB.” A color generation process used in video that combines red, green, and blue to make all colors. All three colors (red, green, and blue) at 100% combine to make white on a video screen; the absence of all three colors (0%) makes black. Also see "Subtractive color process."

Attenuate/Attenuation - To reduce the amplitude (strength) or current of a signal.

Autoswitching - The feature that enables a product to detect which input has an active sync signal and switch to that input.

Balanced audio - The audio signal that is carried on three wires (or five wires for stereo pair), with two of them carrying the same signal but with reversed polarity, and a third wire for shielding. Since the two signal wires would pick up virtually identical noise from outside (common mode noise), and that noise can be canceled out at the receiving end by a differential amplifier, the balanced audio is much less susceptible to hum and interference from long cable runs.

Bidirectional - The ability to move, transfer or transmit in both directions.

Cable equalization - The method of altering the frequency response of a video amplifier to compensate for high frequency loss in cables that it feeds. Also see "Peaking."

CAT 5 - Category 5. Describes the network cabling standard that consists of four unshielded twisted pairs of copper wire terminated by RJ-45 connectors. CAT 5 cabling supports data rates up to 100 Mbps. CAT 5 is based on the EIA/TIA 568 Commercial Building Telecommunications Wiring Standard.

CAT 5e - Enhanced Category 5. The standard for the next higher grade of unshielded twisted pair (UTP) beyond Category 5. The CAT 5e specification was developed to provide more robust support for 1000Base-T. CAT 5e specifies tighter limits than CAT 5 for NEXT, ELFEXT, and return loss.

CAT 6 - Category 6. The standard for the next higher grade of unshielded twisted pair (UTP) cabling beyond CAT 5e. The standard defines components (cable and connecting hardware) and cabling (basic link and channel) for Category 6 channels, as well as Level III field tester requirements.

Coaxial cable - A two-conductor wire in which one conductor completely wraps the other, with the two separated by insulation. Constant impedance transmission cable. Example: 75 ohm, type RG-59 cable used for video signals. Abbreviated as coax.

Component video - Color television systems start with three channels of information: red, green, and blue (RGB). In the process of translating these channels to a single composite video signal, they are often first converted to Y, R-Y, and B-Y. Both three-channel systems, RGB and Y, R-Y, B-Y, are component video signals. They are the components that eventually make up the composite video signal. Higher quality program production is possible if the elements are assembled in the component domain.

Composite video - An all-in-one video signal comprised of the luma (black and white), chroma (color), blanking pulses, sync pulses, and color burst.

Contact closure - The momentary connection of two conductors to complete an electrical circuit. Often used to switch inputs on switchers.

DDC - Display Data Channel. A bi-directional communications standard developed by VESA (Video Electronics Standards Association) that defines a universal data transmission standard for the connectivity between display devices and computers.

DIP switches - Small switches that are used to change settings on printers, computers, interfaces, switchers, modems, etc. They are designed to fit in a DIP (Dual Inline Package) space on a circuit board.

EDID - Extended Display Identification Data - EDID is a data structure used to communicate video display information, including native resolution and vertical interval refresh rate requirements, to a source device. The source device will then output the optimal video format for the display based on the provided EDID data, ensuring proper video image quality. This communication takes place over the DDC – Display Data Channel.

IP Link® - Extron’s high performance IP integration technology specifically engineered to meet the needs of professional A/V environments.

Level - The relative intensity of an audio or video source.

Level control - The level control on some interface products is similar to the contrast control on a data monitor. It can either increase or decrease the output signal level from the interface to a data monitor or projector. This results in greater or less contrast in the picture.

Loop-through - A feature that allows the video signal to be passed through a device relatively unprocessed and sent to a local monitor or other device. The loop-through is separate from the circuits that process a signal for output to the main presentation or recording device(s). Loop-through connections are found on some scan converters and scalers. (Loop-out)

Matrix switcher - A means of selecting an input source and connecting it to one or more outputs. Like a regular switcher, but with multiple inputs and multiple outputs.

MTP - Extron’s acronym for the Mini Twisted Pair line of products

Peak - The highest level of signal strength, as determined by the height of the signal’s waveform.

Peaking - A means of compensating for mid- and high-frequency RGB video bandwidth response in data monitors and projectors and for signal losses resulting from cable capacitance. The higher the frequency and longer the cable length, the more peaking may be required.

Peaking control - Peaking control on Extron products compensates for mid- and high-frequency RGB video bandwidth response in data monitors and projectors and for signal losses resulting from cable capacitance. When using the peaking control a noticeably sharper picture will be seen on all displays regardless of cable lengths. However, 100% peaking may provide over enhancement on short cable runs. Use the position that produces the sharpest image on the display screen. Also called “sharpness” control.

RGB - Red, Green, and Blue. The chroma information in a video signal. The basic components of the color television system. They are also the primary colors of light in the additive color process. Also see "Subtractive color process."

RGBHV - Red, Green, Blue, Horizontal, and Vertical Sync. A five-wire signal where the red, green, and blue video signals, as well as the horizontal and vertical sync signals, are on its own conductor.

RGBS - The Red, Green, and Blue chroma information in a video signal, with a separate channel for the sync signal.

RGsB - Red, Green, Blue, and Sync on Green. A three-wire signal with separate red, green, and blue video signals with the sync (horizontal and vertical) on the green signal.

RJ-45 - Registered Jack-45. A connector similar to a telephone connector that holds up to eight wires, used for connecting Ethernet devices.

RS-232 - An Electronic Industries Association (EIA) serial digital interface standard specifying the characteristics of the communication path between two devices using either DB-9 or DB-25 connectors. This standard is used for relatively short-range communications and does not specify balanced control lines. RS-232 is a serial control standard with a set number of conductors, data rate, word length, and type of connector to be used. The standard specifies component connection standards with regard to the computer interface. It is also called RS-232-C, which is the third version of the RS-232 standard, and is functionally identical to the CCITT V.24 standard.

Serial port - An input/output connection on the computer that allows it to communicate with other devices in a serial fashion data bits flowing on a single pair of wires. The serial port is used with RS-232 protocol.

Sharpness - The definition of the edges of an image. Also see "Peaking."

Sharpness control - Same as Peaking control.

Signal loss - A video problem that shows up as a faint picture for lack of video information.

Skew - Refers to the timing difference which occurs when electrical signals which are traveling over different pairs of cables reach their destinations at different times. The different arrival times of the signals may present a problem when simultaneous arrival with no delay is required.

Skew-Free - A reference to special twisted pair cable in which the length differences between cables reduced to a minimum, thus reducing cable skew.

Smearing - A video problem where objects such as horizontal bars extend past their boundaries. Also called “over-peaking.”

Subtractive color process - Process used in color printing. Mixing cyan, magenta, yellow, and black (CMYK) produces millions of desired colors. Examples: 0% of C, M, Y and K = white (no ink); 100% of C and M = red; 100% C, M, and Y = process black. Also see "Additive color process."

S-video - A composite video signal separated into the luma (“Y” is for luma, or black and white information; brightness) and the chroma (“C” is an abbreviation for chroma, or color information).

Switcher - (1) A device that allows a selection between more than one source, such as video cameras, VCRs, etc. In audio/video, switchers are a means of connecting an input source to an output device or a system. Also see “Matrix switcher.” (2) A term often used to describe a special effects generator; a unit that allows the operator to switch between video camera signals. Switchers are often used in industrial or security applications to switch between video cameras that view certain areas for display on a monitor, or system of display devices. These kinds of switchers do not have sync generators. Also see "Matrix switcher."

SXGA - Super Extended Graphics Array. A graphics standard with a resolution of 1280x1024 (1,310,720 pixels), with an aspect ratio of 5:4. This exceeds XGA (1024 x 768, at 786,432 pixels).

SXGA+ - Introduced in 2004, a graphics standard with a resolution of 1400x1050 (1,470,000 pixels) with an aspect ratio of 4:3.

TP - Twisted Pair. Cable that uses small twisted pairs of wires in a common jacket/sheath to transmit and receive network or telephone signals; can be either shielded (STP) or unshielded (UTP). The Extron product family includes twisted pair transmitters, twisted pair receivers, and twisted pair cabling.

Tweeker - A small screwdriver for making sensitive adjustments to audio/visual and other electronic equipment. An Extron specialty.

Unbalanced audio - An audio output where one of the two output terminals is at ground potential.

UXGA - Ultra Extended Graphic Array. 1600 x 1200. A UXGA display has 1600 horizontal pixels and 1200 vertical pixels giving a total display resolution of 1,920,000 individual pixels that are used to compose the image delivered by a projector.

VGA - Video Graphics Array. A widely used analog interface between a computer and monitor that uses a 15-pin plug and socket. The original VGA resolution was 640x480 pixels.

WSXGA - “Wide-SXGA” defines a class of SXGA displays with a width resolution sufficient to create an aspect ratio of 16:9. Resolution is defined as the number of individual dots that a display uses to create an image. These dots are called pixels. A WSXGA display has 1920 to 1600 horizontal pixels and 1080 to 900 vertical pixels respectively that are used to compose the image delivered by the projector.

WXGA - “Wide-XGA” defines a class of XGA displays with a width resolution sufficient to create an aspect ratio of 16:9. Resolution is defined as the number of individual dots that a display uses to create an image. These dots are called pixels. A WXGA display has 1366 to 1280 horizontal pixels and 768 to 720 vertical pixels respectively that are used to compose the image delivered by the projector.

XGA - Extended Graphics Array. A screen resolution of 1024x768 pixels.

XGA-2 - eXtended Graphics Array card, 2nd generation. Capable of scanning from 31 to 68 kHz and resolutions up to 1600 x 1200 pixels, this card uses a 15-pin HD VGA-style connector.

Y/C - The technical description of S-video. The luminance signal, Y, and the chrominance signal, C, are carried on separate signal/ground pairs. Because the Y channel is carried separately, higher bandwidth is possible and color subcarrier crosstalk is eliminated.