Glossary of cable and connectivity terms

 

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10-Base2 – Short for 10 Megabit, baseband, 200 Meters. Refers to an older Ethernet standard that used RG-58 Thinnet coaxial to network computers in a daisy-chain topology. This system is antiquated.

 

10-BaseT – Short for 10 Megabit, baseband, Twisted pair. An upgrade to Ethernet from 10-Base2, it switched from the coaxial daisy-chain method to using a star topology running over twisted pair cable. This allowed for greater flexibility and reliability. Still used today, although the speeds have increased. See 100-BaseT and Gigabit.

 

100-BaseFX – Short for 100 Megabit, baseband, Fiber cross-connect. See 100-BaseT. Basically, Ethernet over fiber optic instead of twisted pair.

 

100-BaseT – Short for 100 Megabit, baseband, Twisted pair. See 10-BaseT. An upgrade that increased the speed from 10 Megabits per second (Mbps) to 100 Mbps. See also Gigabit.

 

16:9 – Widescreen aspect ratio used for a video display. The display measured is 16 units wide for every 9 units tall. This creates a rectangular viewing area that better represents a movie theater screen.

 

4:3 – Standard aspect ratio used for a video display. The display measured is 4 units wide for every 3 units tall. This creates an almost square viewing area. Standard TV’s and computer monitors use a 4:3 aspect ratio.

 

5.1 – A type of surround sound with 5 distinct sound channels and a LFE (low-frequency effects) channel; Center, Front Left, Front Right, Rear Left, and Rear Right. The .1 refers to the LFE channel, which is so named because it only reproduces the lower 1/10 of the sound frequency (the deep bass tones) of the other channels. Each channel requires a separate speaker. Dolby and DTS both offer 5.1 Surround technologies.

 

6.1 – The same as 5.1, with the addition of a Rear Center channel.

 

7.1 – The same as 5.1, with the addition of a Left Rear Center channel, and a Right Rear Center Channel. In a 7.1 setup, the Rear Left and Rear Right of the 5.1 setup are pushed a bit forward to create a more rounded shape to the sound field.

 

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AC –Alternating Current. An electric current that reverses its direction at regularly recurring intervals. Common household electrical circuits are AC.

 

Active – used to describe a device or circuit that requires power to operate. Opposite of Passive.

 

ADC, or A/D: Abbreviation for analog-to-digital converter. A device used to convert analog signals to digital signals.

 

Adapter – Something that adapts; an adapter is used to change one connector type to another. Typically an adapter refers to a passive adaptation; i.e. a simple physical change in the connection. The signal is not affected. If the signal is changed, it is more appropriate to use the term converter.

 

ADSL - Asynchronous Digital Subscriber Line. See DSL.

 

Ampere - , or amp – the measure of electrical current, named for André-Marie Ampère, a French physicist and one of the main discoverers of electromagnetism. The unit is A, or more commonly, mA (milli-Amps, or one one-thousandth of an amp).

 

Amplification – to boost or increase the strength of an electrical signal. See Amplifier.

 

Amplifier – an electronic device used to increase the power of a signal. The amplifier has one or more inputs, and one or more outputs. The signals coming in are gathered, given a power boost, and sent to the output. Amplifiers are used to send signals a greater distance than they could reasonably travel on their own. Amplifier also refers to a component of an audio/video system that collects line-level signals, processes them, boosts them, and sends the high-level signal to the speakers. In that application, it is sometimes called a receiver, although the amplifier is only one component of a receiver.

 

Analog – a type of signal transmission with an infinite number of values within a specific wavelength. Transmitting and storing analog information requires a great deal of bandwidth and resources. Also, because the values are not discreet, analog signals are more susceptible to interference. However, they are less so to signal loss and often the signal of choice for long distance applications.

 

Antenna – a length of wire, metal rod, or array of metal tubes used to receive radio signal transmissions.

 

Aspect Ratio – relationship in a display between the width and height. See 16:9, 4:3. Aspect ratio is an important consideration when choosing a home theater display. See widescreen.

 

Asynchronous – not synchronized; refers to data communication that does not occur at pre-determined intervals. The time between data segments can be of an arbitrary duration. Most communications between computers and peripherals are asynchronous. Opposite of synchronous.

 

ATA – Advanced Technology Attachment. ATA is a parallel storage interface technology for disk drives and removable media like CD-ROM drives. It was the first technology to integrate the controller onto the drive itself, called IDE or Integrated Device Electronics. Because of this, ATA is also called IDE. However, because many other drive technologies also utilize IDE it is more proper to use the term ATA. ATA supports two drives per channel, one designated as master and one designated as slave. ATA uses a 40-pin ribbon cable which can be bulky and cumbersome to work with, and is one of the things that lead to the development of SATA. After SATA was released, ATA is now more commonly referred to as PATA for Parallel ATA. ATA has evolved over the years to remain viable by increasing the speed of the bus. Typically ATA will be listed with the speed it supports, such as ATA/66, ATA/100, or ATA/133 for 66, 100, and 133 MB/s respectively.

 

Attenuation – an electrical property of a signal, it is the measurement in the reduction of the signal’s strength. Attenuation is measured in decibels, abbreviated dB. It is the opposite of amplification. Attenuation occurs naturally as a signal travels through a wire and if the attenuation becomes too great, the signal becomes unusable. This is why amplifiers are used. Attenuation is also referred to as signal loss.

 

Audio – of or relating to the transmission or reception of sound.

 

A/V – Stands for Audio/Video. Refers to a system that generates both sound (audio) and picture (video). Cables to connect this type of equipment are sometimes referred to a A/V Cables.

 

AWG – Stands for American Wire Gauge. A measurement of the size or thickness of a wire. The larger the number, the thinner the wire. This standard was developed from a series of measuring gauges made in the 1850s by a Rhode Island manufacturer named Brown & Sharpe. See the AWG conversion chart here.

 

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Backbone – see bus.

 

Backward compatibility – of or relating to a device or technology that is compatible with versions that came before it.

 

Balanced – A type of signal transmission. A balance signal typically employs two conductors per signal. One is the signal itself (called “hot”) and the other is a signal that is of opposite polarity (called “return”). Usually this polarity is measured in relation to a common ground. In a similar fashion to differential, balanced signals are able to greatly reduce interference, because the signal is derived from comparing the two signals. Any voltage difference in the signal (due to noise or signal loss) will also occur is its opposite, so the actual signal can be subtracted from the mix. Balanced signals are very popular with professional audio cables such as those used for microphones, mixing consoles, etc. XLR is the most common connector for balanced applications.

 

Banana plug – a single pin connector that bulges in the middle (like a banana) used primarily for speaker connections. Banana plugs connect to binding posts.

 

Bandwidth – a measure of the amount of data that can be transmitted in a fixed amount of time. Digital signals are measured in bits per second (bps), whereas analog signals are measured in cycles per second, or Hertz (Hz).

 

Baseband - A method of communication in which a signal is transmitted at its original frequency. Opposite of broadband.

 

Baud rate – used to refer to the number of bits per second when only one bit is sent per clock cycle. 300 baud = 300 bits per second (bps). Today, most transmission systems are capable of sending more than one bit per clock cycle, so the term bps (bits per second) is used instead.

 

Bend radius – the smallest radius a cable can bend before attenuation occurs.

 

Bi-directional – refers to a parallel printer interface that sends data in two directions; both from the computer to the printer, and from the printer to the computer. Bi-directional signals are used to increase transmission speed, and to allow the printer to report status information such as ink levels or error messages.

 

Binding post – a type of speaker jack. Binding posts have a female jack for banana plugs, and also have a screw terminal for the connection of bare wire or spade lugs.

 

Bit – Binary Digit – The smallest unit of digital information. A bit represents a single value, usually a 1 or a 0. Bits are usually arranged into more meaningful values by combining them into larger units. See Byte.

 

BNC – a type of connector that uses a twist and lock type of retention. No one knows what BNC stands for, but there are several theories, including British Naval Connector, Bayonet Nut Connector, and Bayonet Neill Concelman (named for the alleged creators of the connector). Of the three, the latter seems to be the most feasible. BNC connectors terminate to coaxial cable and are commonly used with video and radio communication equipment, and also older Ethernet networks.

 

Booster – see amplifier.

 

BPS (bps) – bits per second; the number of digital bits sent per unit of time (one second). Used as a measurement of digital data transmission speed.

 

Breaking strength – the pulling force, expressed in pounds, that will cause a conductor to fracture.

 

Broadband - A method of communication in which a signal is transmitted by being impressed to a higher frequency carrier wave. This allows more data to be carried for a longer distance.

 

Bulk – Used to refer to cable or items that are purchased in large amounts. Bulk cable is cable sold in a large roll, typically in 100 ft or higher increments. Bulk cable can also refer to raw, unfinished cable (a cable with no connectors).

 

Bus – the highway on which data travels. The bus is the physical medium that carries the data, typically a cable. In networking, it is also called a backbone.

 

Byte – 8 bits combined into a logical unit. A byte typically represents a single character in a computer system such as the letter “A” or the number “4”.

 

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CRT – Cathode Ray Tube. A type of display that consists of a large vacuum tube, with a screen at the front and an electron gun at the rear. The screen is coated with tiny particles called phosphors that glow when excited by a beam from the electron gun to produce the image. CRT’s are also called direct-view and is the type of display that most people consider when thinking of a TV or computer monitor.

 

Cable – A system for carrying a signal from point to point. A cable is typically made up of individual conductors and a connector at each end. Specific cable types are generally required for specific signal types.

 

Capacitance – an electrical characteristic of a cable. It is a rating of a cable’s capacity to store electricity and is measured in picofarads per foot (pf/ft). As an electrical signal passes through a cable, the cable itself becomes “charged” by the signal. The longer a signal has to move across the wire, the higher this charge becomes. At a certain point, the charge becomes significant enough to actually interfere with the signal itself. Therefore, lower capacitance is desirable as it allows the signal to go further before the “charge” becomes significant. The unit “Farad” is named for Michael Faraday, the discoverer of electromagnetic induction.

 

Case – The chassis or “box” that all of a computer’s components are stored in.

 

Case Mod – Mod, short for modification. A Case Mod therefore is some type of product or process used to modify a computer case. “Case Modding” is currently a popular hobby with technology and computer gaming enthusiasts.

 

CATV – Cable Television. Refers to equipment or technologies used to transmit, receive, or carry cable television signals. CATV cables typically use the F-type connector terminated to 75 Ohm coaxial cable.

 

CCTV: Closed-Circuit Television. A system where video (and sometimes audio) is directly transmitted to specific users and not broadcast to the general public. Most often used for security systems.

 

Centronics – Standard parallel interface used for printers and other parallel peripherals named for the company that developed it, the Centronics Corporation. The printer interface used was a 36-pin connector with two rows of facing contacts on either side of a spaced channel, and used a bail-lock type of retention. The term “Centronics” has come to be used for any connector with that configuration, regardless of the number or contacts or the application.

 

Chrominance – The color part of a video signal. Also called “C”.

 

Cladding - Material that surrounds the core of an optical fiber. It blocks the light from “leaking” out of the core, causing the transmitted light to travel down the core.

 

Client – a computer on a network. A client is a computer or application that relies on a server to perform some operation. See Client/Server.

 

Client/Server – A network architecture which dedicates each computer on the network as a client or a server. Clients rely on servers for resources, such as files, devices, and even processing power. Client/Server architectures are typically more expensive and complex, but they have distinct advantages over peer-to-peer networks. Having files in a central location, for example, makes them easier for all the clients to access and makes it easier for them to be archived. Putting shared devices on a server (such as printers) saves cost by allowing multiple clients to share that single device. Running applications for a central server saves costs because the client machines do not have to be as powerful as the server machine.

 

Coaxial – or, coax – A type of cable composed of a center conductor inside a metal tube or shield. A dielectric material separates the center conductor from the shield, which is covered by an insulating jacket. Coaxial is a popular cable for video because it is highly resistance to signal loss and interference, and can carry a large amount of bandwidth.

 

Comb Filter – An electronic circuit in a display device that separates a composite video signal into its chrominance and luminance counterparts so those signals can be processed. Comb filters can add distortions or artifacts to the video signal which is why technologies that bypass the comb filter like S-Video and Component Video are used.

 

Component Video – This is one of the highest quality types of analog video signals, and is the most common used for Hi-Definition Television (HDTV). Component Video separates the signal into three elements or components; the luminance or picture signal, and two color signals. The three signals are carried on their own conductor, so Component Video cables are three cables with RCA or BNC connectors colored Red, Green, and Blue.

 

Composite Video – The lowest common denominator video signal, found on virtually all consumer grade video hardware today. Composite Video combines all the picture information into a single signal. The connector type used is RCA, and it is typically colored yellow.

 

Computer – a device used for the generation, storage, and retrieval of electronic documents. Typically consists of the computer box itself (also called the case or CPU), an input device such as a keyboard and mouse, and an output device such as a monitor or printer.

 

Conductor – In electrical terms, a conductor is a material that allows electricity to flow freely. In cable terms, the conductor is the physical medium that carries the signal. A cable is typically made up of individual conductors. Copper conductors carry an electrical signal over a single or multiple strands of metal threads. Fiber conductors carry a beam of light over a single or multiple strands of plastic or glass threads.

 

Connector – The physical means by which two things are joined together, both electrically and mechanically. A connector is typically a physical housing that contains a number of contact pins. A plug connector is typically called a male connector, and a socket, receptacle, or jack connector is typically called a female connector. See Gender. The plug is inserted in the socket, making both an electrical contact and a means to hold the cable in place (the mechanical connection, also called retention). Both the electrical and mechanical junctions are important. If the cable falls out, it can’t carry signals; if the electrical connection is bad, the mechanical connection doesn’t do any good.

 

Contact – see Pin.

 

Converter – A device that converts the signal from one type to another type. If the only change is in the physical connection type, it is more appropriate to use the term “adapter”.

 

Core - The central portion of an optical fiber. The actual portion of a fiber optic cable that carries the light signal. The core is typically made of pure glass or plastic, and can be much finer that a human hair. The core is surrounded by the cladding.

 

Coupler – A special type of adapter used to join two cables together that have the same connector type. For example, if you have two six-foot cables you can use a coupler to join them together to get a twelve-foot cable.

 

Crimp – a type of pin to conductor termination method. Crimp pins have little teeth or flanges that are pressed or pinched into the conductor to make electrical contact. See also crimp tool.

 

Crimp Tool – the tool used to affix a crimp pin or connector housing to the conductors in a cable.

 

Crosstalk – a problem that occurs in a cable when the signal in one conductor interferes with the signal in another conductor.

 

Current – the flow of electricity through a wire or circuit. Measured in Amperes.

 

Cut – To separate; when building a cable, what we do to put it into useable segments.

 

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DAC, or D/A: Abbreviation for digital-to-analog converter. A device used to convert digital signals to analog signals.

 

Data – electronic information, coded for transmission or storage.

 

DB (db) – used as a prefix for d-shaped connectors, such as the db-9 or db25. Short form of d-sub.

 

DBS – Direct Broadcast Satellite. A broadcast method for digital audio and video that is beamed from satellites to small receiver dishes. DirecTV and DISH Network are two providers of DBS signals. DBS provides a superior picture and CD quality sound, and in many cases is cheaper than CATV.

 

DC – Direct Current. An electric current flowing in one direction only and substantially constant in value. Electric batteries use DC.

 

Decibel, or dB -  Logarithmic scale measuring the intensity of sound (the sound pressure level); a 10 decibel (dB) increase represents in a doubling of sound level. Also used as the unit of measure for attenuation.

 

Device – Any piece of electronics that attaches to a computer. Devices that are separate from the computer are called peripheral devices, or peripherals. Devices that are mounted inside or as a part of a computer’s case are called internal devices. Can also refer to any electronic apparatus.

 

Device Driver – or simply driver, is a piece of software that acts as a translator between the computer and the device allowing the two to communicate.

 

Dielectric – a material that is a non-conductor of electricity. Dielectric materials are used in cables to separate conductors, or to separate the conductor from the shield. Most common in coaxial cables.

 

Differential – A type of signal transmission. Differential signals are created by sending two components of a signal (a positive (+) component and a negative (-) component) over two separate conductors, typically twisted together (twisted pair). The actual signal is derived at the receiving end by taking the difference between the two component signals. This minimizes signal noise and allows the cable to operate reliably even without expensive shielding technologies. Popular differential applications are SCSI, Ethernet, and USB.

 

Digital – a type of signal transmission with only two discreet states or values; a high and a low, or a one and a zero. Digital signals are typically superior to analog signals because they are easier to store and to manipulate and take less bandwidth to transmit. They are less prone to interference, but are more susceptible to signal loss because as the signal weakens, the values are no longer discreet, and therefore become unusable. This is why most digital signal technologies have transmission length limitations.

 

Digital audio – audio signals that are converted to a digital format. Digital audio provides a cleaner signal because it is immune to interference and provides a more accurate representation of the source material. The digital format also allows a tremendous amount of information to be sent over a single cable, such as a complete 5.1 surround presentation.

 

Digital coaxial – Digital audio over a 75 Ohm coaxial cable.

 

Digital optical – Digital audio over a thin glass or plastic fiber optic cable. Digital optical has a length limitation of about 5 meters. Also called Toslink.

 

DIN – stands for Deutsches Institut für Normung, or German Institute for Standardization, a manufacturing industry standards group. DIN refers to a round connector with pins arranged in a circular fashion, and is commonly used for keyboards, MIDI instruments, and other devices. See also Mini-DIN.

 

Diplexer - A device that combines/splits two or more types of signals of different frequencies into a single output/input. Most commonly used with satellite TV applications.

 

Dolby Digital – the first implementation of Surround Sound that is encoded to a digital signal. See 5.1. Dolby Digital is widely available and is the de facto standard on DVD’s today. Named for the company that invented the technology, Dolby Laboratories.

 

Drain wire – this is a small conductor (typically 28 gauge or smaller) of aluminum or copper that makes physical contact with the shield, often wrapped around or simply lain against the shield. Because a shield is round and covers the whole cable, terminating it is often difficult. Using a drain wire makes terminating the shield more practical, because the shield can then be utilized as if it were a standard conductor in the cable.

 

Driver – See Device Driver.

 

DSL – Digital Subscriber Line. A type of broadband internet service that is carried over standard phone lines. DSL can typically provide speeds up to 1.5 Mbps, which is over 30 times greater than standard dial-up speeds.

 

D-sub – or, d-subminiature. Simply refers to the shape (d) and size (sub or subminiature) of the connector. D-sub (db) connectors are the most common type of connector used on computers and electronics equipment.

 

DTS – Digital Theater Sound. A competing technology for Dolby Digital. Many claim that DTS provides superior channel separation, deeper bass tones, and cleaner overall sound. DTS encoded audio requires much more storage space, so it is not found on every DVD.

 

Duplex, or duplex cable – refers to cable assembly with two separate cable paths, usually one transmit and one receive. Typically used in reference to fiber cables.

 

DVD – Digital Versatile Disc. A 5-inch optical disk that stores audio and video information. It is currently the most popular format for storing movies.

 

DVI – Digital Visual Interface. A set of digital signal standards created by the Digital Display Working Group (DDWG) for the transmission of high-bandwidth digital video information. DVI is commonly used on PC’s for the connection of digital flat panel monitors, but is now becoming a common interface on HDTV equipment. There are two main types of DVI; DVI-D, which is the digital only version of DVI and uses a 24-pin connector, and DVI-I, which adds backward compatibility with analog signals and uses a 29-pin connector. Of the two, DVI-D is the most common.

 

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Elongation – measured as a percentage that a conductor will stretch before it reaches the point of fracture.

 

EMI – Electromagnetic Interference. Any electronic device gives off an electrical field when it is operating. EMI is when the electrical field of one device interferes with the electrical field of another device. EMI is bad for a signal going through a cable as it can corrupt the signal, so to prevent EMI in a cable, a shield is used. Conversely, the shield also prevents the signal going through the wire from causing EMI in other devices. See also RFI.

 

Enclosure – a box or cabinet that holds electronic components.

 

Ethernet – a network architecture and set of standards defined by the IEEE as the 802.3 specification. Ethernet is the standard way that computers get on the Internet and communicate with each other today. Ethernet has evolved over the years from bulky systems that only ran at 10 Mbps (megabits per second) to small fast systems that run at over 1 Gigabit (1000 Mbps). The most common cable used with Ethernet is the Cat5 patch cable, which uses the RJ-45 modular connector, but fiber optic cables can also be used.

 

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Farad – the unit of measure for capacitance.

 

F-Connector, or F-type connector – A round, inside-threaded, barrel connector used with coaxial cable and common for CATV use.

 

Ferrite – , or ferrite bead – a block or cylinder of magnetized iron used to help reduce RFI emissions from entering a cable. It works by creating an inductance field that acts as resistance to the interference…in theory; in practical experience ferrites do little if anything to actually reduce a wide range of interference. This is not a fault of the ferrite itself; it is due to the way it is improperly implemented or due to being made of poor quality materials.

Fiber – or, fiber optic - a type of conductor made of a fine thread of plastic or glass used to carry a signal that consists of pulses of light. Fiber Optic cables are capable of much greater bandwidth capacity than standard electrical cables, and can also go much greater distances without signal degradation.

 

Fibre Channel – A set of standards for a high-speed serial interface, Fibre Channel offers data rates of up to 1.06Gbps. Often used as a backbone technology in storage area networks, Fibre Channel is typically deployed on fiber (as you'd probably expect from the name), but it can also be carried over twisted-pair or coax cable. Fibre Channel’s popularity is waning with the advent of new technologies such as Gigabit Ethernet, Serial ATA, and newer SCSI standards such as SAS (Serial Attached SCSI).

 

FireWire - FireWire is Apple’s trademark for the technology known as IEEE-1394 High Performance Serial Bus, or simply 1394. Developed by Apple in the 1980’s. See IEEE-1394.

 

Flat ribbon – a type of cable named for its shape. The conductors are bonded together and laid flat in a ribbon-like configuration. Flat ribbon cables are commonly used for connection of internal computer peripherals. They are also designated by their number of conductors, such as 40-pin flat ribbon (40 conductors) or 50-pin flat ribbon (50 conductors). The type of connector used on a flat ribbon cable is typically the IDC.

 

Flexibility – the ease with which a conductor or cable can be bent.

 

Flex Life – a rating of a conductor or cables ability to bend repeatedly without breaking.

 

Frequency – The measure of the number of complete electrical cycles that occur within a specific period of time. Frequency is measured is Hertz (Hz), or cycles per second. See bandwidth.

 

Friction fit – a type of retention that has no physical mechanism to it other than simple friction between the male and female contact surfaces. Friction fit retention is used for connections intended to be plugged/unplugged frequently, such as USB and Firewire connectors.

 

Front projection – a type of display that uses a CRT projected onto a large screen mounted to the wall or hanging from the ceiling. This is the type of system a movie theater uses.

 

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Gauge – See AWG.

 

Gender – refers to the orientation of the contacts on a connector as male or female. Male connectors typically have pins, and are called plugs. Female connectors typically have sockets, and are called jacks.

 

Gender Changer – A special type of adapter that simply changes the gender from male to female, or vice versa. Gender changers can also be used as couplers.

 

Gigabit – 1000 Megabits, or 1 billion bits per second. Smokin’!

 

Ground loop – a problem that can occur when you connect a cable between two pieces of equipment that have a difference in their ground potential. This will create noise in the signal going through the cable. The problem typically manifests itself as an audible hum, or a scrolling pattern on a display.

 

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HDTV – High Definition Television. A set of standards for television that produces film-quality images and a widescreen format. Typically, HDTV has 1080 or 720 lines of resolution vs. 480 for standard television. HDTV is still a relatively new technology though, so prices are high and because the standards have not yet finalized there are sometimes compatibility problems.

 

Hex post – Retention hardware used on a connector hood. The hex post screws into the hood, and has a hex nut screw receptacle.

 

Hex nut – A six-sided nut used to retain a screw or thumbscrew.

 

Home Theater – term used to describe an audio/video system designed to bring a movie theater experience into the home by the use of a large screen television and surround sound.

 

Hood – The outer shell that covers a connector. It can be made of metal, plastic, or be molded. It protects the pins and conductors from damage, provides strain relief, and is the anchor for the mechanical retention.

 

Hot Swap - The act or process of removing and replacing an electronic peripheral or component from a device without first powering down the device.

 

Hub – a device used to connect multiple computers or peripherals together so that they may be shared. A hub is typically a boxed shaped device with several ports on it. Each device to be shared plugs into one of the ports. Hubs are common in Ethernet and USB applications.

 

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IDC – Insulation Displacement Connector. A special type of crimp connector. IDC works by piercing or pushing aside the insulator on a wire so that the connector pins can make contact with the conductor material . IDC connectors are typically pre-loaded with the pins. They are commonly used with flat ribbon cables.

 

IDE - Integrated Device Electronics. Refers to a hard drive or storage disk where the controller is integrated to the drive itself. See ATA.

 

IEEE – Institute for Electrical and Electronics Engineers, pronounced I-triple-E. A body of engineers, students, and scientists that develop and govern standards for the computer and electronics industry.

 

IEEE-1284 – A set of new standards set by IEEE in 1994 to upgrade the aging parallel interface. It defined a set of protocols to enable bi-directional communication between the computer and the peripheral, improving speed and functionality.

 

IEEE-1394 –The technology known as IEEE-1394 High Performance Serial Bus, or simply 1394. Developed by Apple in the 1980’s (see FireWire) 1394 is a versatile, high-speed, and low-cost method of interconnecting personal computer peripherals and consumer electronics devices. Similar to USB, but with a few distinct differences. First, FireWire is a peer-to-peer technology, so no host is needed; devices can connect directly together. Second, FireWire is faster with speeds up to 800Mbps (called 1394b, or FireWire800). Even when running at speeds comparable to USB (such as the common 400 Mbps mode) FireWire is able to achieve higher sustained bandwidth throughput due to more intelligent logic circuits. Therefore, FireWire is a much more common interface for Digital Video (DV). Sony has adapted the trade name of i-Link for it’s implementation of the IEEE-1394 technology.

 

i-Link – Sony’s trademark name for the technology know as IEEE-1394 High Performance Serial Bus, or simply 1394. See IEEE-1394.

 

Impedance –Impedance is a measure of how much a component or wire resists the flow of current through it. It is calculated by adding together the electrical properties of resistance and reactance. Because impedance affects the flow of current, it is important for a cable to maintain a constant impedance from one end to the other. Because impedance is a derivative of resistance, it is measured in Ohms.

 

Incompatible – not compatible; will not work together, and there is nothing you do about it.

 

Input – on an electronic device, a connector jack used to allow a signal to enter the device for processing.

 

Insertion Loss - The attenuation that occurs from inserting a connector, coupler, or splice into the signal path on a cable.

 

Insulation – or, insulator – a material that is a non-conductor of electricity, like rubber or plastic. Insulation is used on wires to block the flow of electricity from leaking out of the conductor. The insulation is placed around the conductor itself. See also, jacket.

 

Interference – any type of corruption, such as noise, that degrades an electronic signal. See EMI, RFI.

 

Interlaced - a type of video display where the image is drawn in an alternating pattern. The odd lines are drawn first, and then the even lines are drawn. See also, progressive. On a typical display, this alternating pattern occurs 30 times a second, so it can cause the display to flicker. Interlaced video was developed so that only half an image has to be transmitted at a time, saving bandwidth. Standard televisions are interlaced. Most computer monitors and HDTV’s are non-interlaced.

 

ISP - Internet Service Provider. A company or organization that provides Internet connections to individuals or companies. Popular ISP’s are AOL (America Online) and Earthlink.

 

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Jack – a female connector.

 

Jacket – The outer covering of a cable. The jacket material is typically a type of PVC (Poly-vinyl Chloride). Some jackets are made with FEP (Fluorinated Ethylene Propylene) or other Teflon derivatives when a plenum-rated version of a cable is needed. See also insulator.

 

Jumper -, or jump(s) – in cable or adapter, a jumper is a small wire or solder joint that fuses two or more conductors into one. Many times jumps are needed to fulfill the signal requirements of a particular cable’s pinout.

 

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Keyboard – an input device. The typewriter-like object used to input data into a computer.

 

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LAN – Local Area Network. Refers to a computer network or segment of a network that is confined to a single physical space, such as a building or group of buildings (such as a campus). Multiple LAN’s can be connected together via telephone lines, radio waves, or the Internet. See WAN (Wide Area Network).

 

Latch , or latch-clips – see squeeze-latch.

 

LCD – Liquid Crystal Display. A type of display that consists of a layer of liquid crystals sandwiched between two layers of glass. As an electrical current is applied to the crystals, they change their shape allowing more or less light to shine through. LCD displays are popular because they are bright, sharp, thin, and lightweight. They are most commonly used on laptop computers.

 

LED – Light Emitting Diode. A circuit that emits light when an electrical current is applied to it.

 

Letterbox – a technique used to show a widescreen image on a standard 4:3 aspect ratio display. This is accomplished by fitting the image to the width of the center of the screen and placing black bars over the empty space at the top and bottom of the screen.

 

LFE – Low Frequency Effects. The .1 in 5.1, it is the audio channel that carries only low frequency information of 80 Hz and below (the deep bass sounds).

 

Line Level – the low level audio signals that connect between devices. Eventually, the line level signals will need to be sent to an amplifier. They do not have enough power to drive speakers directly.

 

Luminance – the brightness and darkness (black and white) portion of a video signal. Also called “Y”.

 

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Meter – Metric measurement of length. 1 Meter is equal to 3.28 feet. Centimeters are 1/100 of a meter. 1 Centimeter is equal to 0.39 inches or roughly 1/3 of an inch. Millimeters are 1/1000 of a meter. 1 Millimeter is equal to 0.039 of an inch, or about 1/32 of an inch.

 

Mini-Din – A type of DIN connector that is smaller in diameter, with the pins arranged in rows rather than in a circular manner. The most common mini-DIN connectors are the 4-pin version used for S-Video, and the 6-pin version used for PS/2-style keyboards and mice.

 

Modular – when used in reference to a cable or adapter, refers to telephone-like square plastic connectors. Also called an RJ connector. As with other connector types, modular connectors come in different sizes. The most common modular connector is the RJ-45 used with Ethernet networks, and the RJ-11/12 uses for telephones.

 

Molding, or molded – A method used to seal or encase a connector hood in a mold of plastic or rubber via an injection molding process. Molded hoods provide superior strain relief and an attractive appearance. Because the connector is sealed, it also prevents tampering. Most off-the-shelf PC cables are molded cables.

 

Monitor – a display device. This is the screen that shows the image for you to view.

 

Mono – a single channel, typically in reference to audio.

 

Mouse – an input device. It controls the cursor or pointer on the monitor. Buttons on the mouse are used to make selections. The name comes from its rounded shape and attached cable, which has the appearance of a mouse and its tail.

 

Multimode – a term used for a fiber optic cable with a core thick enough to carry multiple modes (beams) of light.

 

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Network – a system of connected computers. The purpose of a network is so the connected computers can easily share data, peripherals, or printers. The most popular type of network today is Ethernet and, of course, the Internet. See also LAN, WAN, peer-to-peer, client, server, topology, protocol, router, switch, hub.

 

Node – a processing location on a network. A node can be a client, a server, or a device, such as a printer.

 

Noise – electrical interference.

 

Non-interlaced – a type of video display where the image is drawn in an single pass, as opposed to interlaced. Because the image is drawn in a single pass, flicker is eliminated. Standard televisions are interlaced. Most computer monitors and HDTV’s are non-interlaced. See also, progressive.

 

NTSC - National Television Systems Committee. Federal government agency that established the analog color television standard used in the United States. Delivers 525 lines of resolution at 60 half-frames per second.

 

Nut – a threaded receptacle for a screw. See thumbscrew.

 

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O.D., or OD – Outer Diameter or Outside Diameter. A cable measurement of the thickness of a cable’s jacket when measured from the outside.

 

Ohm – the unit of measure of electrical resistance and impedance.

 

Output - on an electronic device, a connector jack used to allow a signal to exit the device.

 

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Packet – a piece of data formulated in a specific pattern so it can be transmitted over a network. Information is broken into smaller packets so that sending it can be easier to manage. As the packets are collected at the receiving end, they are reassembled into the data. The protocol determines the design of the packets.

 

Pair – two conductors that are bonded or twisted together in a cable. Pairs are used in differential and balanced applications.

 

PAL – Phase Alternating Line. Television broadcast standard developed in England and Germany and used in many countries throughout Europe. Delivers 625 lines of resolution at 50 half-frames per second.

 

Pan and scan - a technique used to show a widescreen image on a standard 4:3 aspect ratio display. This is accomplished by fitting the image to the height of the center of the screen and cropping off portions of the image to the sides.

 

Parallel – refers to a type of interface where the signal lines are running over multiple channels running parallel to each other. Think of parallel as a multi-lane highway for data. Common parallel interfaces are IEEE-1284, SCSI, and ATA. Parallel cables are typically thicker and larger because of the number of conductors necessary. Opposite of serial.

 

PATA – Parallel ATA. Simply called ATA (or incorrectly IDE/EIDE) before SATA was introduced. The P was added to clearly distinguish the two technologies. See ATA, SATA.

 

Passive – used to describe a device or circuit that does not require power to operate. Opposite of Active.

 

Patch cable – any cable used to patch or connect one device to another device. Most common in reference to Ethernet cables.

 

Peer-to-peer – A type of network architecture in which each computer has equivalent responsibilities in regard to the sharing of data or resources. The opposite of a client/server architecture. Peer-to-peer architectures are generally simpler because they do not require dedicated server hardware, but the performance can suffer greatly under a heavy load.

 

Peripheral – a device that attaches to a computer. Common peripherals are printers, keyboards, mice, etc.

 

Phosphor – a substance that glows when an excited by an electrical field. Phosphors are used in display devices. Typically, phosphors that give off the colors red, green, and blue are arranged to produce an image.

 

Pin – The actual metal contact surface inside a connector. The pin is the part that is actually physically terminated to the conductors in the cable. Pins can be both male and female (see gender). Pins are typically made of brass, tin, gold, nickel, or combinations of them.

 

Pinout -, or pinmap – the signal map of a cable. It shows how the signal conductors in the cable are arranged from one connector to the other. The pinout is what makes the signals flow correctly so the cable can work for its intended purpose. If the cable you are using does not have the correct pinout, data will not flow and your application will not work.

 

Pixel – picture element. The smallest component of a video display. Pixels are the individual dots that make up the image. The number of pixels is measured by the resolution of the display. The more pixels available, the sharper the image.

 

Plasma display, or Plasma TV, or Plasma screen - A type of display that consists of a layer of plasma gas sandwiched between two layers of glass. As an electrical current is applied to the plasma it gives off energy which excites phosphors coated on the glass, producing an image. Plasma displays are bright, sharp, and thin. They are the “TV on the wall” you see in the commercials.

 

Plenum, or plenum-rated – (pronounced plnm) A type of cable jacket with fire-rated properties typically made of Teflon or Teflon derivatives. The building codes in most localities require the use of fire-rated cables when they are run through the plenum spaces of a building to prevent the spread of fire or the release of toxic gases that can result from the burning of standard PVC materials. The plenum space is typically the open space between a drop ceiling and the roof, or the open space inside walls, for which the cable gets its name.

Plug – a male connector.

 

Poke – to push; when building a cable, this refers to the action of placing the conductor pins into the connector housing.

 

Polarity – An electrical circuit has two sides; positive and negative. The polarity is which condition exists for a particular side. It is important to maintain polarity when connecting electrical circuits, or current will not flow. In some cases, it can damage the equipment.

 

Port – a jack.

 

Progressive, or progressive scan – see non-interlaced.

 

Protocol – the language or format that is transmitted from one device to another. In order for two devices to communicate, they must be able to use the same protocol.

 

Push terminal – a type of speaker wire connection. See Spring Connector.

 

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So lonely….

 

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Rack – a metal frame or enclosure used to mount equipment.

 

RFI – Radio Frequency Interference – A special type of EMI (electromagnetic interference) that is specific to transmitted fields within the radio frequency band, typically over 1Mhz. Whereas EMI is a by-product of electrical devices, RFI is typically a deliberate signal transmission such as a radio station, TV, cordless phone, etc. Because RFI is a type of EMI, is can be just as detrimental to the signals in a wire and may need to be shielded against.

 

RCA – A type of connector primarily used for connecting audio and video equipment. It is a single pin connector with a surrounding shield ring that was developed by the company whose name it bears. Also called phono-plug, because the connector was originally develop for phonographs.

 

Rear projection – a type of display that uses a CRT projected onto a mirror and reflected onto the back of a large screen. What most people think of when considering large screen or big screen TV’s.

 

Receiver – a component or an audio system that consists of an amplifier, pre-amplifier, signal processor, tuner, and junction point for the other components. The receiver is the heart of any audio/video or home theater system. Also used to define the collector end of a signal path.

 

Refresh rate – also called scan rate, or frequency rate. It is the number of times a display can paint its screen with a complete image.

 

Resolution – the measure of the number of pixels a display can produce. It is shown as the number of pixels (horizontal) by the number of lines (vertical). The higher the resolution, the more detailed the image.

 

Resistance –the measure of the amount of opposition of a body or substance to the electrical current passing through it. The more resistance you have in a cable, the less current flows through the cable. Resistance is measured in Ohms, named for Georg Simon Ohm, a German physicist.

 

Retention – the mechanical anchor mechanism used to secure two connectors together. Typical retention methods are thumbscrews, squeeze latches, or friction fit.

 

Router – A special type of Ethernet switch that provides a superior level of packet routing. Routers are often used as the bridge between a LAN and a WAN.

 

RS-232 – a set of standards and protocols used for the transmission of serial data. RS-232 is one of the most robust methods for transmitting data, but it is also one of the most confusing, due to the almost near infinite number of ways it can be implemented. There is no such thing as a “standard” RS-232 cable.

 

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SATA – Serial ATA, or Serial Advanced Technology Attachment. SATA is the latest evolution of the aging ATA storage technology interface. SATA advantages are speed (up to 150 MB/s currently), smaller and thinner cables and connectors, and lower power requirements. Opposite of PATA.

 

SCSI – Small Computer System Interface. Pronounced “skuzzy”. A set of standards designed for the connection of peripheral devices to computers. SCSI was ratified in 1986 (earlier versions date back to 1979) and has evolved much over the subsequent years to keep up with demands of speed and reliability. SCSI is a parallel bus interface that requires termination. The evolution over the years has created a large array of connectivity options for SCSI, and makes it one of the most confusing technologies to implement. See the SCSI charts for more information on the different options available.

 

Screw – see thumbscrew.

 

Semiconductor - A material that is neither a good conductor of electricity (like copper) nor a good insulator (like rubber). Semiconductors are used to make computer chips, and other electronic components like transistors.

 

Serial - refers to a type of interface where the signal lines are run over a single channel one bit at a time. Think of serial as a single-lane highway for data. Common serial interfaces are RS-232, USB, and SATA. Serial cables are typically thinner and smaller because of the few number of conductors necessary. Opposite of parallel.

 

Server – A computer or device or a network that manages applications or resources. Servers are powerful computers often dedicated to a singular task. Types of servers are: File servers – used to store, retrieve, and archive files; Print servers - manage one or more printers; Network servers - manage network traffic; and database or application servers – process one or more applications or programs. See Client/Server.

 

Shield – Used in a cable to provide a protective layer of the signal conductors from EMI (Electro-Magnetic Interference) and RFI (Radio Frequency Interference). The shield works by providing a low-resistance path that collects the stray interference signals and grounds them to earth so that they do not get into the signal wires. There are two types of shields used in cables; a foil shield, and a braided shield. When both are used in a cable, it is called a double-shield, or foil and braid.

 

Shell – See Hood. Also used to refer to the electrical ground in a connector; the termination point for the drain wire or braid.

 

Signal – the electrical pulses that travel through a cable whose variations represent data. The signal is the thing that you want to get from point A to point B when you connect a cable. Because the information is coded, it must be decoded at the other end. This is why you cannot just connect anything to anything (incompatible) or you must use a converter.

 

Signal loss – attenuation.

 

Solder – a type of pin to conductor termination method. To solder means to fuse two conductive surfaces together by using a molten bridge material (called solder, or solder flux) typically made of a mixture of lead and tin. The two surfaces are placed together and covered with the molten solder, which quickly cools to form a permanent bond between the materials. See soldering iron.

 

Soldering Iron - The tool used to heat and place the solder.

 

Solid – a type of conductor. Solid conductors are made with a single rigid piece of metal, typically copper. Solid conductors are better for use when the cable is going to be placed in a permanent position, such as inside a wall or over a ceiling. The rigid nature of the solid wire makes it easier to pull through the space and it hold its shape and position better. Solid wire can actually fatigue and eventually break if bent or twisted repeatedly. If you are not permanently placing the wire, consider stranded wire.

 

Solid State - Electronic component composed of transistors and integrated circuits using no vacuum tubes.

 

Spade Lug - Type of U-shaped speaker connector attached to the ends of speaker wire and used to connect the wire to the input or output terminals of amplifiers and speakers.

 

Splice – Joining two or more conductors together without using any type of connector, such as soldering or twisting them together. Splices are often crude, and can create a great deal of insertion loss.

 

Spring Connector -  Inexpensive method of connecting speaker wires to amplifiers (particularly amplifiers integrated into receivers) and speakers using a thin sheet of metal that is pushed against bare speaker wire or a pin-type connector by a small spring.

 

Squeeze-latch – A method of retention used on a cable that consists of a spring loaded clasp and hook mechanism. The retention is released by squeezing the latch arms which release the clasp. Relaxing the latch engages the clasp. The latch and clasp are typically found on the male connector, and the female connector would have the hook.

 

Stranded – a type of conductor. Stranded conductors are made with a series of fine, almost hair-like, strands of metal (usually copper) woven or wrapped together. Stranded conductors are better for use when the cable needs to be more flexible, such as when you need to route the cables through you computer desk or audio/video rack, because it can bend or move around easily without fatiguing or breaking. If you are not permanently affixing the wire, stranded is the perfect choice. Otherwise, consider solid wire. Most off-the-shelf cables are made with stranded conductors.

 

Strain relief – a component of a cable assembly that is used to protect the cable from stress at the point where it exits from the connector hood. Typically consisting of a rubber grommet or molded ridges, it allows flexibility in a cable without putting stress on the termination point.

 

Strip – to remove; in cable parlance, specifically to remove the insulation from a conductor. This is done to prepare it for termination, whether crimp or solder. It can also refer to the removal of the outer jacket to expose the conductors for use.

 

Subwoofer - Special form of speaker used to reproduce only the lower portion of the audible frequency spectrum usually from 80 Hz down to or below 20 Hz. See LFE.

 

Surge protection, or surge protector – a device used to protect against lightning and other electrical power fluctuations that can damage electronic equipment.

 

Surround sound – literally, surrounded by sound. A speaker setup that puts the listener in the center of a series of speakers so that sounds can be heard from any direction. Popular with home theater setups and cinemas.

 

S-Video - The “middle of the road” video signal, found on most consumer grade video hardware today. S-Video separates the picture into two separate components, Chrominance and Luminance. This lets the video signal bypass the comb filter, which helps maintain signal integrity. S-video typically uses a 4-pin mini-DIN connector. Also known as S-VHS, or Super VHS, it was developed in the 80s by JVC as a response to attempts by Sony to corner the VCR market with their Beta technology.

 

Switch – a electronic gate that is used to open or divert a signal from one point to another. Switches are used to share electronic devices by allowing more that one to connect to the same input or output and switching between them. In Ethernet, a switch is a special type of hub that provides superior performance by intelligently moving the data from point-to-point.

 

Synchronous - synchronized; refers to a data communication that occurs at pre-determined intervals. The time between data segments is of a specific duration of evenly spaced intervals. Opposite of asynchronous.

 

 

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Television, or TV - a video display that has an integrated tuner used to reproduce visual images. A display device that does not have a built-in tuner should be more appropriately be called a monitor.

 

Tensile strength – the pulling force, expressed in P.S.I. (pressure, or pounds per square inch), that will cause a conductor to fracture.

 

Termination – to end; to terminate a wire means to put a connector or connector pin on it. You are putting an end to the cable. In SCSI applications, it means you are putting an end to the SCSI chain by the use of a terminator.

 

Terminator - A terminator is device used to end a signal chain, typically used for SCSI and older type of Ethernet such as 10-Base2. The terminator brings an abrupt end to the electrical signals moving down the cable. Without the terminator, the signals would hit the end of the cable and bounce back, causing interference and data corruption. Also, a cybernetic organism played by Arnold Schwarzenegger.

 

Thinnet – A type of Ethernet so named because the cables used were a thin RG-58 coaxial, versus the much thicker RG-11 coaxial cable used in earlier designs. See 10-Base2.

 

Thumbscrew - A method of retention used on a cable. Thumbscrews are screws of various thread sizes that have a knob or burl on the end making them easy to turn by grasping between the thumb and forefinger. The thumbscrew is typically found on the male, and the female connector would have a nut with a matching thread pattern.

 

THX - Set of specifications and certifications designed by Lucasfilm to ensure optimum reproduction of movie sound and video in movie theaters and home theaters. Stands for Tomlinson Holman eXperience. Tom Holman was a Lucasfilm sound engineer.

 

Toslink – the most common type of digital optical connector. Comes in two types; a square shaped plug used on home theater equipment, and a mini-plug (similar to a headphone plug) used on handheld digital devices like mini-disc players.

 

Topology – the shape or design abstract of a LAN or connected system. Three principle topologies are used; bus topology – all nodes are connected in a linear fashion to a single bus or backbone (also called a daisy-chain) ; star topology – all nodes are connected to a central point, typically a hub; and ring topology – all nodes are connected together in a closed loop.

 

Transformer – an electronic component that is used to convert the power from a wall jack (AC) to something that is useable by an electronics device (DC). Transformers are the main components of power supplies and AC adapters. Also, robots in disguise.

 

Transistor – a device composed of semiconductor material that amplifies a signal or opens or closes a circuit. Invented in 1947 at Bell Labs, transistors have become the key ingredient of all digital circuits, including computers.

 

Tuner – an electronic device used to receive coded signal transmissions and decode them into audio and video information.

 

Twisted pair – two conductors twisted together. The purpose of twisted pair is to help reduce EMI/RFI interference by utilizing a principle called differential or balanced signaling. If the transmitting device does not utilize either of those methods, there is no technical advantage to using a twisted pair cable. Cat-5 cable, used for Ethernet, is the most famous type of twisted pair cable used today.

 

 

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USB – Universal Serial Bus. An interface system designed for the easy connection of peripherals to a computer. USB is the most popular connection interface today, due to its plug-n-play nature and faster speeds. It was designed to replace older legacy interfaces like parallel, serial, and PS/2 and is well on its way to doing just that. USB has three operating speeds; low-speed which is 1.5 Mbps, full-speed which 12 Mbps, and high-speed which is 480 Mbps (called USB 2.0). USB is a host-based technology, which means that peripherals require the services of a host. The PC acts as the host and up to 127 different peripherals can be connected in series using hubs. All the logic control (and sometimes the power) is provided by the host. Peripherals have no intelligence on their own, so they cannot be directly connected together.

 

USB 2.0 – Universal Serial Bus version 2.0. The latest iteration of USB, which upped the speed 480 Mbps. USB 2.0 is fully backward compatible with older USB devices. To utilize USB 2.0, the computer’s host controller must be USB 2.0, the device itself must be USB 2.0, and any interim connections such as hubs must also be USB 2.0. If any component in the chain is not USB 2.0, you will not get USB 2.0. Things will still work, just at the slower USB speeds.

 

UTP – unshielded twisted-pair.

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Video - of or relating to the transmission, reception, or storage of pictures or moving pictures.

 

Voltage – electrical pressure. A measure of the force or "push" given the electrons in an electrical circuit. Named for Alessandro Volta, an Italian physicist best known for inventing the battery. Voltage is measured in Volts, which uses the symbol V. Also common is the designation VAC, for Volts Alternating Current, or VDC for Volts Direct Current which are used with power supplies.

 

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WAN – Wide Area Network. Multiple LAN’s connected together via telephone lines or radio waves. The Internet is a WAN. See network.

 

Wavelength – The distance between one peak or crest of a wave of light, heat, or electrical signal and the next corresponding peak or crest.

 

Wire – see Conductor. Wire is often used in lieu of the word cable, but the term conductor is a better definition.

 

Widescreen – a display with a wider aspect ratio, typically 16 units wide for every 9 units high. See 16:9. Widescreen displays are popular because they more accurately represent the aspect ratio of a movie theater and present a better viewing experience.

 

Wire Gauge – see AWG.

 

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So lonely…

 

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Y/C – Luminance/Chrominance. Another term for S-Video.

 

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So lonely …