Appendix B Home Technology Integration Glossary

Appendix B HomeTechnology Integration Glossary

The following are the terminology, phrases, and most of the major standards publishers you will most probably encounter or should know for working as a home technology integrator or a installer.

CROSS-REFERENCE

For a more complete list of the organizations you should be acquainted with as a home technology professional, see Appendix D.

10Base2 (Data Networking)

The IEEE 802.3 standard for 10Mbps thin coaxial cable Ethernet networks that have a maximum segment length of 185 meters. Also known as Thinnet or Cheapnet.

10Base5 (Data Networking)

The IEEE 802.3 standard for 10Mbps thick coaxial cable Ethernet networks that have a maximum segment length of 500 meters. Also known as Thicknet and Yellow Wire.

10BaseT (Data Networking)

The IEEE 802.3 standard for 10 Mbps Ethernet baseband networking over unshielded twisted pair cable.

100BaseT (Data Networking)

The IEEE 802.3 standard for Fast Ethernet or 100 Mbps Ethernet baseband networking over unshielded twisted pair cable.

100BaseFX (Data Networking)

The IEEE 802.3 standard for fiber optic Ethernet networks with 100 Mbps bandwidth.

100BaseT4 (Data Networking)

See 100BaseTX.

100BaseTX (Data Networking)

The IEEE 802.3 standard for UTP Ethernet networks with 100 Mbps of bandwidth. Also known as 100BaseT4.

1000BaseTX (Data Networking)

The IEEE 802.3 standard for UTP Ethernet networks with 1000 Mbps of bandwidth. Also called Gigabit Ethernet.

110 block (Data Networking/Structured Wiring)

An IDC system used to terminate telephone and data cables. Also referred to as a 110 connector or 110 punchdown.

110 punchdown tool (Data Networking/Structured Wiring)

A special tool that is used to press wires into the IDC terminals on a 110 block.

568A (Data Networking/Structured Wiring)

The EIA/TIA standard defining RJ-45 jack pin-to-wire attachment for telecommunications wiring in commercial buildings.

568B (Data Networking/Structured Wiring)

The EIA/TIA standard defining RJ-45 jack pin-to-wire attachment for data communications wiring in commercial buildings.

570 (Data Networking/Structured Wiring)

The EIA/TIA standard defining standard telecommunications wiring in residential buildings.

802.3 (Data Networking)

The IEEE reference standard that defines media access, cabling standards, and connectivity for Ethernet networks.

802.11a (Data Networking)

An IEEE standard for wireless networking.

802.11b (Data Networking)

An IEEE standard for wireless networking.

802.11g (Data Networking)

An IEEE standard for wireless networking.

A

A-line lamp (Lighting)

A standard incandescent lamp used in indoor residential lighting.

AC (alternating current) (Electricity)

An electric current in which the flow of the current is alternatively reversed. The frequency of AC electricity in the U.S. is 60 hertz (Hz), and in many parts of the world, it is 50 Hz.

Accent lighting (Lighting)

Lighting used to highlight a particular object or room feature.

Accumulator air coil (HVAC)

A coil on some heat pump types that can be used as either an evaporator or condenser.

ADSL (Asymmetric Digital Subscriber Line) (Data Networking)

A broadband DSL-telephone line technology that transmits voice, video, and data over existing copper telephone wires at very high speeds. ADSL provides faster data transfer speeds for download and slower data transfer rates for upload.

Air change (HVAC)

The amount of air needed to completely replace the air in a room, zone, or building.

Air diffuser (HVAC)

An outlet through which airflow is directed into a desired direction.

Air handler (HVAC)

The fan, blower, filter, and housing of an HVAC system.

Air infiltration (HVAC)

Air that leaks into a room or building through cracks, windows, doors, and other openings.

Air terminal (HVAC)

An air distribution outlet or diffuser.

Airflow (HVAC)

The distribution or movement of air.

AM (Amplitude Modulation) (Audio, Video, Data Networking )

The transmission method that merges a transmitted signal into a carrier signal by modulating the amplitude of the carrier.

Ambient lighting (Lighting)

The general lighting of an entire area or room made up of natural and artificial light.

Ampere (Electricity)

A standard unit measure of the rate of electron flow or electrical current in a conductor.

Amplifier (Audio, Video)

A device that increases the amplitude of a signal retaining the same waveform pattern of the original signal. Amplifiers are analog devices.

Amplitude (Audio, Video, Data Networking)

The wavelength of a transmitted signal that represents the strength or volume of the signal measured in decibels.

Analog/analogue (Audio )

The electrical representation of a signal that retains the properties of the original data.

ANSI (American National Standards Institute) (Standards)

A standards organization that administrates standards for the United States and represents the United States at the International Standards Organization (ISO).

Appletalk (Data Networking)

The network protocol suite used on proprietary Apple Computer networks.

Artifacts (Audio, Video)

Image or sound distortion that can occur when an audio or a video signal is compressed to a low bit rate. Also referred to as noise.

Armored cable (Electricity)

Electrical cable assembly in which two or more insulated conductors are protected by a flexible metal conduit.

ASCII (American Standard Code for Information Interchange) (Data Networking)

The 8-bit character encoding scheme that is the standard for computer data interchange.

ATSC (Advanced Television Systems Committee) (Video)

An international standards organization that establishes voluntary technical standards for advanced television systems.

Attenuation (Data Networking)

The decibel loss of signal that occurs when a signal is transmitted through a medium.

Attenuator (Audio, Video)

A passive transmission device used to reduce signal strength.

AWG (American Wire Gauge) (Standards)

A standard guideline used to measure wire diameter. Lower AWG values represent larger wire diameters.

B

Backbone (Data Networking)

The primary media of a data network that runs the length of the network and interconnects all network segments.

Backmount (Structured Wiring)

The mounting method used for attaching add-in modules inside a structured wiring distribution panel.

Balance point (HVAC)

The lowest outdoor temperature at which a heat pump is able to meet the heating demands of a home without using a supplementary heat source.

Balanced line (Electricity)

A cable with two conductors with identical properties that provide common symmetry to ground.

Ballast (Lighting)

An electrical device used in fluorescent or HID fixtures to supply sufficient voltage to start and operate a lamp. A ballast also limits the electrical current during lamp operation.

Balun (balanced to unbalanced) (Electricity)

A device that is used to convert an unbalanced electrical line into a balanced line.

Bandwidth (Data networking)

The amount of data that can be transmitted over a medium in a specific period. The standard bandwidth measurement is megabits per second (Mbps).

Bare wire (Lighting)

An electrical conductor wire that has no covering or insulation. Commonly ground wires in prewired lighting fixtures are bare wires.

Baseband (Data Networking, Video)

A transmission mode that transmits digital data using time division multiplexing (TDM). Baseband transmissions use the entire capacity of the transmission media.

Baseband video (Video)

Video signals that are unmodulated, such as NTSC, PAL, SECAM, and others, and carry no audio component.

Battery backup (Electricity)

A rechargeable battery that is maintained in standby mode to supply power when an interruption in the normal power supply occurs.

Bend radius (Structured Wiring)

The angle to which a cable can be bent without damaging the cable or affecting its electrical properties.

Bit (binary digit) (Data Networking)

The representation of a binary one or zero using positive and nonpositive electrical values, respectively.

Bit rate (Data Networking)

The transmission speed of a network media expressed in bits. Bit rate is equivalent to bandwidth.

Blocking (Structured Wiring)

A horizontally placed wooden or metal brace set between two wall studs.

Bluetooth (Data Networking)

A wireless RF communications technology used to link mobile devices into ad hoc networks.

BNC (Bayonet Neill Concellman) (Audio, Data Networking)

A standard coaxial cable connector that uses barrel and T connectors to join coaxial cables or connect to a networking or source device.

BPS (bits per second) (Data Networking)

A measurement of the number of bits transmitted over a medium in one second.

Branch circuit (Electricity)

A household electrical circuit that branches from the main electrical panel to an outlet box or a device.

Bridle ring (Structured Wiring)

A cable management device that is used to loosely hold cabling in a loop, or plastic, wire, or other flexible materials.

Breaker (Electricity)

A toggle switch device that is used to connect and disconnect the power to an electrical circuit by nonautomatic means and also to pen a circuit by automatic means when a predetermined level of current passes through it. Circuit breakers can be reset.

Broadband (Data Networking)

The high-speed transmission media that transmits data at speeds of 1.544 Mbps or faster. (Audio, Video) The transmission mode for data, voice, and video using frequency division multiplexing (FDM) such as is used with cable television systems. Broadband transmissions use a single medium to carry several channels at once.

BTU (British Thermal Unit) (HVAC)

A heating system measurement that measures the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit.

Byte (binary digit?eight) (Data Networking)

A grouping of eight bits that is used to store or represent numeric values or ASCII characters in computer storage.

BX Cable (Structured Wiring)

A legacy cable type that is now illegal for use in homes.

C

Cable (Structured Wiring)

A bundle of separated insulated wires wrapped with a single protective outer jacket.

Cable clamps (Structured Wiring)

Metal clips inside a distribution panel, outlet box, or other electrical box that are clamped down on a cable using screws to hold the cable in place.

Cable tie (Structured Wiring)

See Tie-wrap.

Capacitance (Electricity)

The capability of a material to store an electric charge. Capacitance is measured in farads.

Cat (category) 3 cable (Structured Wiring)

A four-pair TP cable once used for telecommunications and data networking that is now replaced by Cat 5 or Cat 5e cabling in the standards. Cat 3 cable is the minimum cable requirement for 10BaseT Ethernet networking.

Cat 5 cable (Structured Wiring)

A four-pair TP cable that provides a higher standard than Cat 3 cable because of an increased number of twists on the wire pairs and better resistance to interference. Cat 5 cable is the minimum cable requirement for 100BaseT and below Ethernet networking.

Cat 5e (expanded) cable (Structured Wiring)

The currently recommended category TP cable for use in residential cabling systems. Cat 5e cable is compatible with 1000BaseT and below Ethernet standards.

Category cable (Structured Wiring)

TP cabling is rated into several numbered categories, ranging from category 1 (Cat 1) to category 7 (Cat 7), as specified by the EIA/TIA 568 cabling standard. The higher the category number, the higher the information capacity of the circuit.

Cathode (Lighting)

An electrode in a fluorescent lamp that emits or discharges electrons to the cathode at the opposite end of the lamp.

CATV (Cable Access Television) (Video)

An RF distribution system that distributes television broadcast programs, original programs, premium programming, and other services using a network of coaxial cable.

CCD (Video)

Light detecting circuit arrays used in video cameras, scanners, and digital still cameras. Advantages include good sensitivity in low light and the absence of the burn-in and phosphor lag found in CRTs.

CCTV (Video)

A closed circuit television distribution system that limits the reception of an image to those receivers directly connected to the origination point by coaxial cable or microwave link.

Central monitoring station (Security)

A facility of a privately owned protection service company that receives remote alarm signals and acts based on customers requests.

Central monitoring station (Surveillance)

A central location in a home where surveillance images captured by video cameras are viewed and monitored.

CEDIA (Custom Electronic Design and Installation Association) (General)

A global trade association of companies that specialize in planning and installing integrated electronic systems in the home.

CFM (cubic feet per minute) (HVAC)

A standard measurement for airflow that measures the amount of air passing a stationary point.

Chandelier (Lighting)

A hanging light fixture that is often used as the focal point in a room or area.

Channel (General)

A single path for communications. Channels may be one- or two-dimensional.

Channel (Video)

A defined band within the 6 MHz RF spectrum that transmits the audio and video carriers of a television signal.

Circuit (Electricity)

A continuous loop of electrical current.

Circuit breaker (Electricity)

See Breaker.

Cladding (General)

A low refractive index material that surrounds the core of an optical fiber causing the transmitted light to travel down the core and protects against surface contaminant scattering.

CO (carbon monoxide) (Security)

An odorless and colorless gas that is often called the “silent killer.” Faulty furnaces can emit CO gas, which can poison the occupants of a home and can be lethal after extended exposure.

CO (central office) (Communications)

A term for the local telephone system’s switching center. The nearest CO to a home is also called an end office (EO) or a local exchange (LE). The telephone lines that enter a home at the NID are terminated at the CO.

CO detector (Security)

A sensor that can detect the presence of CO gas in a home and alert the occupants of the hazard.

Coaxial cable (Communications/Video)

A two-conductor copper cable made up of a solid central conductor, a dielectric layer, and a second conductive layer that is usually a metal braid or mesh, all of which are inside an insulating jacket.

CODEC (Compress/Decompress) (Video)

An algorithmic video service that encodes and decodes video files for transmission over network media.

Color temperature (Lighting)

A measure of the appearance of the light produced by a lamp that categorizes the light as either warm or cool.

Compact fluorescent lamp (CFL) (Lighting)

A small, single-end fluorescent lamp that can be installed into an incandescent lamp socket.

Composite video (Video)

The complete video signal including the brightness (Luminance) signal, the blanking and sync pulses, and the color (Chrominance).

Compressor (HVAC)

A pump used to increase the pressure of a refrigerant or gas between low-pressure and high-pressure cycles.

Conductor (General)

A material that offers little resistance to the flow of electrical current.

Conduit (Structured Wiring)

A metal or plastic tube that is used to protect the cabling running through it.

Connecting block (Communications)

A plastic block containing metal wiring terminals used to establish connections from one group of wire to another with insulation displacement connections (IDC). Also called a terminal block, a punchdown block, a quick-connect block, or a cross-connect block. Used in residential wiring for terminating CPIW and provides a means for a telephone set to connect to the CPIW through a modular jack.

Control (General)

A multiposition mechanical device, usually wall mounted, that allows for adjustment (attenuation or amplification) of the signal from the source or distribution device to an end device.

Concealed wiring (Structured Wiring)

Cable installed in a wall, between floors, in attics, or I in crawlspaces to prevent the cable from being tampered with and to improve the aesthetics of the home.

Condenser (HVAC)

A pump that receives vaporized refrigerant from an evaporator and compresses it into a liquid state for return to the refrigerant control unit.

Contacts (Security and General)

Electrically conductive points, or sets of points, that open and/or close circuits that ultimately control electrical loads.

Contrast (Video)

The range of dark and light values in a picture or the ratio between minimum and maximum brightness.

Control panel (Security)

A device that arms, disarms, and supervises an alarm system at the user’s premises.

Controller (General)

A device or group of devices that serve to govern, in some predetermined manner, the electric power delivered to the apparatus it is connect to.

Convergence (Video)

The alignment of the red, green, and blue video on a projected display such that the lines produced by the three “guns” appear to form one clearly focused white line and the perceived single image is clearly focused.

Cove lighting (Lighting)

A type of architectural lighting that uses light sources shielded by a ledge or recess to distribute light across a ceiling or wall.

CPIW (Customer Provided Inside Wiring) (Communications)

Any and all telephone wiring inside a home and beyond the NID.

Cross-connect (Structured Wiring)

A physical connection made between patch panels or punchdown blocks that interconnects cable runs from source devices and end devices.

Crossed pair (Structured Wiring)

A wiring termination error on TP cabling in which the two conductors of a wire pair are attached incorrectly exchanged with the conductors of a different wire pair at one end of a cable.

Crosstalk (Structured Wiring)

Interference on a cable caused by electrical energy being absorbed into adjacent conductors of a cable that may cause signal loss.

CRT (Video)

Cathode ray tube.

Current (General)

The flow of electricity in a circuit, measured in amperes.

D

Daisy chain (Structured Wiring)

A wiring technique in which multiple terminations are made on a cable or wiring branch that interconnects one device on the branch to the next.

Damper (HVAC)

A device located inside a duct that is used to adjust the airflow.

Data Rate (Data Networking)

The number of bits of information that can be transmitted per second.

dB (Decibel) (Electricity, Audio)

See Decibel.

DC (direct current) (Electricity)

An electrical current that has no alternations or reversals.

Decibel (dB) (Electricity, Audio)

A measurement for the loudness or strength of a signal. One decibel is considered to be the smallest amount of difference between two sound levels that a human ear can detect. One Bel indicates that an input signal is 10 times quieter or weaker than the output signal. A decibel is one-tenth of a Bel.

Definition (Video)

The fidelity of a video picture reproduction. The clearer the picture, the higher the definition.

Demarc (Demarcation point) (Communications)

The point at which a telephone company’s lines terminate and are interconnected into a home’s CPIW. Typically, the demarc of a home is the NID.

Device (General)

Any electrical or mechanical equipment attached to a cable or wire.

DHCP (Dynamic Host Configuration Protocol) (Data Networking)

A networking protocol that allows network nodes to self-configure for IP address, subnet masks, default gateways, and more.

Digital Communicator (Security)

A device that can be triggered automatically to electronically dial one or more preprogrammed telephone numbers using digital codes and report alarm or supervisory information to a receiver.

Dimmer control (Lighting)

An electrical device that controls the brightness of one or more lamps by varying the electrical current flowing to the lamps.

DIP (Dual Inline Package) switch (Data Networking)

A set of toggle switches, rockers, or slides that are used to select settings on a modem or electronic circuit board.

Distortion (Video)

An undersized change in a wave form or signal.

Distribution panel (Structured Wiring)

A centrally located panel that organizes and interconnects cable-based technologies, including data, voice, audio, and video signals throughout a home.

Dolby Pro Logic (Audio)

Advanced surround sound system for the home using two front speakers, two rear-channel speakers for ambiance reproduction, and a front center channel speaker for dialog and “logic steering.”

Door contact (Security)

A two-part magnetic sensor that detects when a door is opened and generates a trip signal.

Downlight (Lighting)

A light fixture that is typically recessed into a ceiling or an architectural feature that concentrates its light in a downward direction. Also called can or recessed can.

Drop wire (Communications)

A cable used to connect a home to telephone services that may either be underground or above ground and terminates at the home’s NID.

Drywall (General)

Also called Sheetrock (a brand name) or wallboard, drywall is a gypsum-based wall covering material that is installed in large sheets as a substitute for plaster on interior walls.

DSL (digital subscriber lines) (Data Networking)

A broadband DSL-telephone line technology that transmits voice, data, and video over existing copper telephone wires at very high speeds. See ADSL.

DSL modem (Data Networking)

A type of modem that connects a computer to a DSL network that connects to the Internet. Once connected, DSL modem users usually have a continuous connection to the Internet.

Duct (HVAC)

A pipe or enclosed conduit used to control and direct the flow of air from an air-handling device.

Ductwork (HVAC)

The system of ducts in a home.

Duplex receptacle (Electricity)

An electrical outlet that includes two AC power plug-in sockets.

DVD (digital versatile disc) (Video)

An optical disc system using MPEG-2 compression technology and the side of a CD-ROM that can store about 133 minutes of digital video.

E

EIA (Electronic Industry Association) (Structured Wiring)

A trade association of electronic equipment manufacturers that develops and publishes standards.

EIA/TIA 568 (Structured Wiring)

See 568A and 568B.

EIA/TIA 570 (Structured Wiring)

See 570.

Electrical box (Structured Wiring)

Also called outlet box, an electrical box is a metal or plastic box that is mounted to wall studs to hold electrical receptacles, light switches, and structured wiring jacks and outlets. Structured wiring runs terminate at electrical boxes.

ELV (Extra low voltage) (Electricity)

Electricity with voltage not exceeding 50 volts AC or 120 volts DC.

Emergency lighting (Lighting)

Lighting, typically powered by battery backup, that is used when the normal electrical supply is interrupted and the lighting system is not available.

EMI (Electromagnetic Interference) (Structured Wiring)

Interference in signal transmission or a reaction on a cable caused by low-frequency waves emitted from electromechanical devices.

Entry delay (Security)

A timer in most security system controllers that provides a homeowner time to disarm the security system before an alarm is sounded.

Ethernet (Data Networking)

A star or bus topology networking technology for computer data communication defined in the IEEE 802.3 standards that operates over twisted-pair, coaxial cable and RF at speeds up to 1000 Mbps. See 10BaseT.

Exit delay (Security)

A timer in most security system controllers that provides a homeowner with time to leave a home after arming the security system and setting off an alarm.

Expansion slots (Data Networking)

Slots or spaces inside a computer or controller that are used to connect additional circuit boards (cards).

F

F-type connector (Structured Wiring)

A threaded barrel connector used to terminate coaxial cable in video applications.

Fiber Optics (Structured Wiring)

Plastic or glass cable that carries a large capacity of information suing light (modulated light waves) and is immune to electrical noise, lightning, and induced voltages.

Firewall (Data Networking)

Dedicated hardware and/or a software system that protects against intrusion on a network from systems external to the network.

FireWire (General)

A reference to IEEE 1394 1995 standard. A data communication scheme that manages digitization, compression, and synchronization processes.

Fish tape (Structured Wiring)

A coil or steel tape that is used to guide a cable through a wall from above or below.

Fixture (Lighting)

A permanently installed and connected light or electrical device that consumes electrical power.

Fluorescent lamp (Lighting)

A low-pressure mercury electric-discharge lamp that has a phosphor coating on the inside of a glass tube to transform UV energy into visible light.

Foot-candle (fc) (Lighting)

A measurement for the amount of light reaching an object in the United States.

FPS (Frames per second) (Video)

The number of video frames captured or displayed in one second.

Frequency (General)

The number of cycles per second in an electrical signal, measured in Hertz.

FDM (Frequency division multiplexing) (Data Networking, Communications)

A communications technology that transmits multiple signals over a single communications link, such as cable television systems and wireless networks. Each signal is assigned a separate frequency.

FT4 (Fire Type 4) (Structured Wiring)

A cable jacket material rating for nontoxic, nonflammable materials used for the insulation and outer jackets of low voltage cable, such as speaker wire.

Furnace (HVAC)

The part of a heating system that converts gas, oil, or electricity into heat.

Fuse (Electrical)

A removable device that completes a circuit at the fuse box that will break if the circuit should have an overload or a short occurs on the circuit.

Future-proofing (General)

The practice of designing and installing wiring and/or a system that provides a home with the flexibility, expandability, and adaptability to support new and emerging technologies without requiring new wiring.

G

GA (gauge) (General)

Identifies the physical size of a wire. The lower the AWG (American Wire Gauge) number, the bigger the wire.

Gain (Audio)

A measure of amplification on a device expressed in dB for the highest frequency of operation.

Gateway (Structured Wiring)

The entry point of services in to a residence.

General lighting (Lighting)

Uniform ambient lighting of a room or area without using special lighting, such as task lighting or accent lighting.

GFCI (Ground Fault Circuit Interrupter) (Electricity)

Sometimes called GFI (Ground Fault Interrupter), this is a specific circuit protection outlet or breaker that protects homeowners from shocks. GFCI outlets are typically installed in kitchens and bathrooms.

Ghosting (Video)

Positive or negative images displaced in time from the actual image caused by signal interference from multiple paths of signal reception.

Gigahertz (GHz) (Data Networking)

A network frequency of one billion cycles per second.

Glare (Lighting)

Light coming into an eye directly for a light source that can harm vision and cause visual discomfort. Indirect glare is light reflected into an eye from a nonlight source surface.

Glass break sensors (Security)

Sensors that detect the sound or vibration of glass breaking and generate a trip signal.

Ground (Electricity)

A conductive entity with a zero electrical potential that is neither positively nor negatively charged.

Ground wire (Electricity)

One of the three common circuit wires. The ground provides a safety route for returning current. The ground circuit is joined with the neutral conductor at the main service panel.

Ground fault (Electricity)?

Current that has been misdirected from a hot or neutral lead to a grounding element such as a wire, box, or conductor.

H

HA (home automation) (General)

The use of a computer or microprocessor-based controller to control the functions and scheduling of home systems.

Halogen lamp (Lighting)

A type of incandescent lamp that contains halogen gases, such as iodine, chlorine, bromine, or fluorine, that impede the degradation of the tungsten filament. Also called a tungsten halogen lamp or a quartz lamp.

HAN (home area network) (Data Networking)

A local area network (LAN) inside a single home.

Handheld remote (General)

A portable handheld control device.

Hand-over section (Security)

If the security system detects an entry or exit through the primary entry/exit point, the entry or exit delay feature is engaged. However, if an entry or exit is made through any other point, the alarm is sounded.

Hardware (Data Networking)

The physical components of a computer or network system, including the Internet gateway, monitor, hard drive, printer, modem, network adapter, keyboard, etc.

HDTV (high-definition television) (Video)

A high-resolution, wide-screen picture format and transmission standard.

HID (High-Intensity Discharge) (Lighting)

Lamps that produce more lumens per watt and have longer lives than most other lamp types. HID lamps include mercury vapor, metal halide, high-pressure sodium, and low-pressure sodium.

High temperature sensor (Security)

A sensor that detects a rise in the ambient temperature of a room or area beyond a certain preset level and generates a trip signal.

Heat loss (HVAC)

The amount of heat lost from a space to be conditioned, measured in BTUs.

Heat pump (HVAC)

A compression cycle system that uses the heat in outdoor air to supply heat to a home or to remove heat from the home to cool it.

Hertz (General)

A unit of signal frequency equal to one cycle per second.

Home network (Data Networking)

A peer-to-peer network that allows users to share data, peripheral devices, and Internet resources on a common network inside a home.

Home run (Structured Wiring)

A wiring method where every cable is terminated at a central distribution facility and pulled directly to a single device, hub, or group of devices wired in series.

Hot wire (Electricity)

One of the three common circuit wires with neutral and ground. The current flow travels on the hot wire.

House Code (Lighting)

An alpha character (A-P) setting on an X-10 PLC device that is used to indicate an item or area/zone within the home. This code setting is combined with a Unit Code (1-16) to uniquely identify the X-10 device.

HTI (home technology integration) (General)

The integration of a home’s control and entertainment and other systems based on a structured wiring system and through the use of automated controllers.

HTI+ (General)

The certification examinations produced by the Computer Technology Industry Association (CompTIA) that certify the abilities of an HTI technician to install, troubleshoot, and maintain home automated systems.

Hub (Data Networking)

A network clustering device that connects several network-ready devices to the network media using a shared bandwidth.

HV (High voltage) (Electricity)

Electrical lines that carry voltage in excess of 1,000 V AC or 1,500 V DC.

HVAC (Heating, Ventilation, and Air Conditioning) (HVAC)

The integrated system that heats, cools, and ventilates a home.

I

IEEE (Institute of Electrical and Electronics Engineers) (Data Networking)

IEEE is a trade organization of engineers, scientists, and students that develops standards for the computer and electronics industry.

Internet gateway (Data Networking)

Also called a residential gateway or a home gateway, an Internet gateway provides a link between a home network and the Internet.

IP (Internet Protocol) address (Data Networking)

A 32-bit binary logical address that identifies a computer on a TCP/IP (Transmission Control Protocol/Internet Protocol) network.

IDC (Insulation Displacement Connector) (Data Networking, Structured Wiring)

A type of wiring terminating connection where the insulating jacket is removed from the connector when the wire is inserted/pushed/forced into the split connector with tines. This eliminates the need to strip wires first.

Impedance (General)

The resistance and reactance of a conductor or component measured in ohms. The lower the ohm value, the better the quality of the conductor.

Incandescent lamp (Lighting)

A filament heated to the point of incandescence by an electric current inside of a glass bulb produces Light.

Induction (General)

Creating an electric current on a circuit from the magnetic influence of an adjacent circuit.

Instant start (Lighting)

A type of fluorescent lamp that starts without the need for preheating the cathodes or a starter.

IP Telephony (Data Networking)

Using Internet protocols to exchange voice, fax, and other forms of information traditionally carried over dedicated circuit-switched connections of the public switched telephone network.

IR (infrared) (General)

A transmission technology that uses infrared light to transmit command signals and data. IR signals are also used in motion detectors and IR beam trip sensors.

Internet (Data Networking)

An internetwork of networks around the world that provides access to information, electronic mail, graphics, and other media on content servers connected to the network.

I/O (Input/Output) (Data Networking)

The operations of a computer that accept data inputs and transmit data outputs to and from peripheral devices.

ISDN (Integrated Services Digital Network) (Data Networking)

A telephone system of digital voice and data transmission services carried over the PSTN.

ISO (International Standards Organization) (Standards)

An international membership organization that develops computer and telecommunications standards, among others. ANSI represents the United States at the ISO.

ISP (Internet service provider) (Data Networking)

A company or organization that provides Internet connection services to subscribers.

Isolation (Video)

The amount of separation or loss between two channels or signals.

J

Jack (Structured Wiring)

The female component of a jack and plug connector that is attached to a cable as a terminator at an outlet or interconnect.

Jacket (Structured Wiring)

The outer protection covering of wire or cable that may also provide additional insulation.

K

Knockout (Structured Wiring)

A plug or piece of an electrical box or panel that can be removed to provide a pass-through for cable to enter or exit the box.

Kilohertz (KHz) (Data Network)

The equivalent of a frequency of 1,000 cycles per second.

Keypad (General)

User interface and input devices that are used to control the functions of one or more integrated systems. In a security system, a keypad is used to arm or disarm the system. In an audio/video system, keypads are used to select source devices and control volume.

Kilowatt (kW) (Lighting)

The equivalent of 1,000 watts.

Kilowatt hour (kWh) (Lighting)

The amount of kilowatts used by a device in one hour of operation.

Kilobyte (KB) (Data Networking)

The equivalent of 1,000 bytes of data.

L

Lamp (Lighting)

A light source, such as an incandescent, a halogen, a HID, or a fluorescent lamp. Also called a light bulb.

LCD (liquid crystal display) (Video)

Utilizes two transparent sheets of polarizing material with a liquid containing rod-shaped crystals between them that respond to electrical currents and align to create dark images. LCD panels do not emit light but are often backlit or sidelit for better viewing.

LCD Projector (Video)

Utilizes LCD technique, separating red, green, and blue information to three different LCD panels where the appropriate colored light is then passed through and combined before exiting through the projector lens.

Lead (Structured Wiring)

A short length of conductor wire loose in a box or service panel.

LED (light-emitting diode) (General)

A small electronic device that produces light when electricity is passed through it. LEDs are commonly used as indicator lights on keypads and other control devices.

Light fixture (Lighting)

A complete lighting device that consists of a lamp, housing, and power connection.

Line Conditioner (General)

Contains multiple protection devices in one package to provide electrical noise isolation and voltage regulation.

Line Doubler (Video)

Doubles the number of scan lines in a video picture. Fills in the space between the original lines, making them less noticeable and increases the brightness of the picture.

Line voltage (Electricity)

The normal or nominal voltage level of a line. In the United States, the line voltage of a home is typically 120 volts AC.

Local area network (LAN) (Data Networking)

A computer network in which two or more computers are connected with a communications medium for the purpose of sharing resources. Local area networks are typically created in a small geographical area, such as a home.

Load (Lighting)

Applies to all current-carrying devices on a given electrical circuit or feeder.

Logic circuit control (Security)

The system used with PIR devices to analyze changes in signal frequency to generate a trip signal, such as in a motion sensor, to determine movement before sounding an alarm. Also determines whether the object detected is a person or a pet to prevent a false alarm.

Loss (General)

The energy dissipated by a transmission line.

Louver (Lighting)

A diffuser made of opaque or translucent material in a geometric design to prevent a lamp from being viewed directly and to minimize glare.

Low temperature sensor (Security)

A sensor that detects decreases in the ambient temperature of a room or area to a preset limit and generates a trip signal.

Lumen (Lighting)

The amount of light produced by a lamp is measure in lumens.

Luminaire (Lighting)

An architectural lighting effect or fixture.

LV (low voltage) (Electricity)

An electrical circuit that carries voltage not exceeding 1,000 volts AC or 1,500 volts DC.

M

MATV (Multiple Access Television) (Video)

The method used for broadcasting television signals through the air.

Mbps (Megabits per second) (Data Networking)

The equivalent of one million bits of data transmitted in one second.

MHz (MegaHertz) (General)

The equivalent of a frequency with one million cycles per second.

Mixer (Audio)

A device that will “mix” two or more input signals to form a combined outlet signal.

MMOF (multi-mode optical fiber) (Structured Wiring)

Transmission medium that uses glass or plastic strands to carry light impulses.

Modem (modulator/demodulator) (Data Networking)

A telephone communications device that modulates digital data into analog data for transmission over a telephone line and demodulates the analog data into digital data at the receiving end for use by a computer.

Modulation (Audio, Video, Data Networking)

Raising a signal to a higher frequency by changing amplitude, frequency, or phase.

Motion detector (Security, Lighting)

A sensor that can detect movement or the presence of a person in a room or area to sound an alarm or merely turn on or off the lights.

Mounting bracket (Structured Wiring)

A bracket attached to a wall stud during rough-in that allows the mounting of a faceplate during trim out. Also called a low-voltage mounting bracket.

Mud ring (Structured Wiring)

A bracket attached to a wall stud during rough-in that ends up mounted flush with the drywall for the attachment of a faceplate during trim-out.

Multizone (General)

A home automation or home technology integration system set up that allows separate areas of a home to operate independently of other areas of the home.

Modular outlets (Structured Wiring)

Multiuse outlets that allow for a variety of jacks to be mixed into a single outlet faceplate. Modular jacks are snapped into the faceplate in any pattern desired.

N

NEC (National Electric Code) (Standards)

The NEC is a guideline for electricians, electrical contractors, engineers, and electrical inspectors put out by the NFPA that is generally accepted as the building wiring standard in the United States.

NEMA (National Electrical Manufacturer’s Association) (Standards)

An association of manufacturers that develops technical standards for electrical products.

Network (General)

Two or more computers or peripheral devices connected by a communications medium.

Network adapter (Data Networking)

The device that provides the interconnection and transceiver services to connect a computer or network-ready device to a network.

Network cable (Data Networking)

The physical wire medium used to connect two or more computers or peripheral devices.

Neutral wire (Electricity)

One of the three common circuit wires. The neutral wire returns current to the power source. The neutral conductor is joined with the ground at the main service panel.

NEXT (near-end crosstalk) (Data Networking)

Interference caused by the induction of a signal from one wire pair into another pair at the transmitting end of a cable.

NIC (network interface card) (Data Networking)

A network adapter that is installed in a computer as an expansion card and manages the flow of information over the network.

NID (network interface device) (Communications)

The interface device where the telephone company’s lines interconnect with the residential wiring. Also called the demarc.

NM (nonmetallic) cable (Electricity)

An electric service cable that is sheathed in a plastic material.

NMC (nonmetallic, corrosive) (Electricity)

An electric service cable that is sheathed in a solid plastic jacket for use in wet or corrosive areas, but is not approved for underground use.

Node (Data Networking)

Any network device where a network cable terminates.

Noise (General)

In a cable or circuit, any extraneous signal that tends to interfere with the signal normally present in or passing through the system.

Noise reduction (Audio, Video)

Processes used to reduce the amount of noise in an audio or video signal.

Normally Closed (General)

Circuit or switch where the contacts are closed during normal operation.

Normally Open (General)

Circuit or switch where the contacts are open during normal operation.

NTSC (National Television Standards Committee) (Video)

A color television broadcast signal standard that is used in North America and Japan.

O

Occupancy Sensor (Security and Lighting)

Control device that detects the presence of a person in a given space. Commonly used to detect intrusion in a security system or control lighting systems and HVAC.

Ohm (General)

The unit of measure for the resistance in a conductor.

Off-air (Video

RF signals (typically TV) that can be received by a conventional antenna system, including VHF and UHF broadcast stations.

Ohmmeter (General)

An instrument for directly measuring resistance in ohms.

P

PAN (Data Network)

Personal area network.

Parallel circuit (General)

Circuit interconnection where all components share a common positive and common negative connection.

Patch cords (Structured Wiring)

The cabling used to interconnect terminations at the central distribution panel.

Patch panel (Data Networking)

An interconnecting device that is used to terminate home-run cabling and connect it to distribution devices using patch cords.

PAL (Phase Alternation by Line) (Video)

The television signal format used in Europe and several South American countries.

PCI (peripheral component interconnect) (Data Networking)

An internal communications and expansion bus on computers. Most network interface cards are PCI compatible.

PCMCIA (Personal Computer Memory Card International Association) (Data Networking)

PCMCIA is a standard for hot-swappable cards developed for use with portable PCs.

Peer-to-peer (Data Networking)

A simple kind of network that sets up a conversation between two machines without a middle man.

Pendant light (Lighting)

Lighting fixtures used for either task or general lighting that are suspended from a ceiling.

Peripheral device (Data Networking)

External computer devices that are attached to the computer, such as CD-ROM drives, modems, and printers, through an interface cable.

PIP (Picture-In-Picture) (Video)

Display of a small picture with a larger picture, each from its own video source.

PIR (passive infrared) sensor (Security)

A detector device that senses changes in the radiation in the infrared band.

Pixel (picture element) (Video)

A video image is composed of individual dots called pixels that create the image patterns and colors.

PLC (powerline control) (Data Networking)

The use of electrical AC wiring for networking transmissions of signals.

Plenum (General)

Airflow space between the actual ceiling and a drop ceiling where ductwork for an HVAC system is installed.

Plenum-rated cable (Structured Wiring)

A cable that has a fire retardant coating that complies with local and national building codes and is suitable for installation in air ducts and plenum spaces.

Plug pack (Security)

A transformer that converts 120 or 240 volts AC to 16 volts DC to power a security system controller.

Port (Data Networking)

A receptacle on a computer or patch panel.

POTS (plain old telephone system) (Communications)

Analog telephone service that runs over copper wires based on the original Bell telephone system.

Prewire (Structured Wiring)

The installation of structured wiring in a home before the drywall is installed during new construction.

Protocol (Data Networking)

A set of rules or guidelines that govern the communication between two applications, computers, or networks.

PSTN (Public Switched Telephone Network) (Communications)

The switched telephone network that carries long distance calls and point-to-point network communications.

Punchdown (Structured Wiring)

A method for securing wire to a contact where the insulated wire is paced in a terminal groove and pushed down with a special tool. As the wire is seated, the terminal displaces the wire insulation to make an electrical connection.

Punchdown block (Data Networking)

See 110 block.

Punchdown tool (Data Networking)

A spring-loaded tool that is used to insert conductors into IDC contacts when terminating on a 110 block.

PVC (polyvinyl chloride) (General)

Material most commonly used for the insulation and jacketing of cable.

R

Raceway (Structured Wiring)

A metal or plastic channel used to hold electrical or structured wiring in a floor.

Rapid start (Lighting)

A fluorescent system without starters that requires one to two seconds of warm-up before beginning to emit light.

Rated life (Lighting)

The time in which 50 percent of a large quantity of a certain lamp burns out.

Reactance (General)

Measure of the combined effects of capacitance and inductance on an alternating current.

Recessed downlight (Lighting)

A light fixture that is recessed into a ceiling that concentrates its light downward.

Refrigerant (HVAC)

The substance used in a refrigerating mechanism that absorbs heat in an evaporator by changing its state from liquid to a gas and then releases its heat in a condenser as it is returned to a liquid state.

Register (HVAC)

A device that combines a grille and damper to cover an air opening.

Relay (General)

An electromechanical switching device.

Remodel box (Structured Wiring)

An electrical box designed for use during remodeling projects for installing electrical receptacles such as HYPERLINK "http://www.netday.org/" l "jack" jacks or light switches in existing walls.

Remote alarm (Security)

An alarm signal that is transmitted to a remote central monitoring station.

Repeater (Data Networking)

A network device that amplifies and regenerates signals so they can travel for longer distance on a cable.

Reset (Security and General)

To restore an electrical component or a alarm to its original (normal) condition after improper performance or an alarm signal.

Residential gateway (Data Networking)

See Internet gateway.

Resistance (General)

The amount of opposition a cable has to the flow of electrical current that is measured in ohms.

Resolution (Video)

The density of lines or dots for a given area that make up an image. Resolution determines the detail and quality in an image.

Retrofit (General)

A modification to an existing building.

Return air (HVAC)

Air drawn into a heating unit after being circulated in a room by the HVAC system supply.

RF (radio frequency) (General)

Transmission of wireless signals over a high-frequency carrier.

RFI (radio frequency interference) (General)

Interference inducted into a conductor from radio frequency signals on a nearby carrier.

RG6 (radio grade 6) coaxial cable (Data Networking)

Type of coaxial cable with a 20-gauge center conductor that is the current standard for data communications over coaxial cable as it allows for higher bandwidth than RG59.

RG59 coaxial cable (Video)

A type of coaxial cable typically used for video signal transmission.

RGB (red, green, and blue) (Video)

The chroma information in a video signal. The basic components of the color television system.

RGB monitor (Video)

A color monitor that accepts separate red, green, and blue input signals to produce a high-quality picture.

Rheostat (General)

A variable resistor.

Ring (Communications)

The side of a two-wire circuit that is connected to the negative side of a power source at the telephone company CO.

RJ-11 (Communications)

A modular jack/plug connector that accepts a single pair of conductors. Used for single line telephones and modems.

RJ-31X (Security)

A modular jack/plug connector that is used to interconnect a security system to a telephone distribution panel and allows for seizure of an in-use phone line.

RJ-45 (Data Networking)

A modular jack/plug connector that is used to terminated twisted-pair cabling per EIA/TIA 568 termination standards.

Romex (Electricity)

A brand of nonmetallic-sheathed cable that is also the generic name used for NM sheathed cable.

Rough-in (Structured Wiring)

The phase of a structured wiring project in which the boxes, cables, and in-wall connections are installed. Rough-in occurs before the drywall is installed.

Router (Data Networking)

A device where the basic function is to efficiently route network traffic from one network to another network.

Run (Structured Wiring)

The path of a length of cable from a distribution panel to an outlet or other termination point.

S

Secam (Systeme Electronique Couleur Avec Memoire) (Video)

A color TV standard developed in France.

Sensor (Security)

A device designed to produce a signal or other indication in response to an event or stimulus within its detection.

Serial Interface (Data Networking)

An I/O port that transmits data one bit at a time in contrast to parallel transmission that transmits multiple bits simultaneously. RS-232 is a common serial signaling protocol.

Series wiring (Structured Wiring)

See daisy chain.

Server (Data Networking)

An application running on a centralized computer that processes requests from network clients (nodes).

Service drop (General)

The overhead conductors between the electrical supply, such as the lat pole, and the building being served.

Service loop (Structured Wiring)

A length of cable coiled near the end of a cable run to facilitate future changes in the wiring system.

Service entrance (SE) (Electricity)

The point where the incoming electrical line enters a home.

Service lead (Electricity)

An incoming electrical line that supplies power to a service panel. Also called supply lead.

Service panel (Electricity)

The distribution facility that ties the service lead to the interior electrical circuits of a home. The service panel is typically a main circuit breaker panel or a fuse box.

Set point (HVAC)

The temperature setting a thermostat is to maintain in a room or area.

Setback thermostat (HVAC)

An electronic programmable thermostat that can be set to provide different temperature settings for different times of the day.

Set-top box (Video)

A generic term for a device connected between the television set and the cable service coming in. It performs selection and decryption processes.

Sheetrock (General)

A brand name for drywall material. See Drywall.

Shield (Structured Wiring)

A metal braid, mesh, or foil placed around a cable to conduct return current and to prevent signal leakage or interference.

Short circuit (General)

The condition caused when a current flow is interrupted short of or before reaching the device terminating the cable. A short circuit is caused when a hot conductor comes into contact with neutral or ground conductors.

Shunt (Security)

To remove some portion of an alarm system from operation, allowing entry into a protected area without initiating an alarm signal.

Signal (Security and Communications)

Any visible or audible indication that can convey information. Also, the information conveyed through a communications system.

Signal strength (General)

The intensity of a signal measured in volts (V), millivolts (mV), microvolts (uV), or dbmV.

Silent alarm (Security)

A remote alarm without local indication that an alarm has been transmitted.

Single-zone (General)

A whole-house system in which all devices operate from a single controller.

Siren (Security)

A sounding device that emits a harsh and loud sound when a trip signal is received from a directly connected sensor or the security system controller.

Skin effect (General)

The tendency of alternating current to travel only on the surface of a conductor as its frequency increases.

SMOF (single-mode optical fiber) (Structured Wiring)

A type of fiber optic cable that carries a single signal stream over long distances.

Smoke detector (Security)

A device where an electrical circuit runs through a chamber where two electrodes are placed very close together to allow electricity to cross the gap, completing the circuit. Should smoke particles collect on one or both of the electrodes, the circuit is broken and a trip signal or an alarm is generated.

Snow (Video)

Visual noise displayed on a television screen caused by excessive signal noise on a circuit.

Speaker siren (Security)

A siren that receives audio signals from the security system controller for playback.

Spike (General)

A momentary increase in electrical current that can damage electrical equipment.

Splice (General)

The joining of two or more cables together by connecting the conductors pair to pair.

Splitter (Video)

A device that divides (or combines) the RF energy on the coaxial cable to two or more cables. Splitters are also two-way and they combine as well as divide.

Star topology (Structured Wiring)

A wiring pattern where each cable run emanates from a central distribution facility and is terminated at a single device. See Home run.

Starter (Lighting)

The electrical device that works with a ballast to start a fluorescent or HID lamp.

Stereo (Audio)

A process of using separate signals on separate channels for the left and right audio, thereby giving depth, or dimension, to the sound.

STP (shielded twisted-pair) (Structured Wiring)

A type of twisted pair cable that includes a foil shielding around each wire pair.

Streaming media (Video)

This type of network-download video file allows a user to watch the media content of a file without first downloading the entire file. The user is able to watch the content while the download is in progress.

Strobe light (Security)

A high-intensity light that strobes when an alarm is activated.

Structured wiring (Structured Wiring)

A system of installing home wiring in which all cable runs are distributed from a central distribution panel using a star topology and home-run cable pulls.

Subwoofer (Audio)

A loudspeaker that reproduces very low sounds usually in the range of 20 Hz to 1000 Hz.

Super VHS (Video)

A video tape player that combines with compatible S-VHS tape to produce images featuring an increase in HRLS and a sharper picture.

Supply (HVAC)

The ductwork that carries conditioned air to a room.

Surge (General)

A rapid rise in current or voltage usually followed by a fall back to a normal level.

Surround sound (Audio

A system that separates the various components of the sound track, then disperses them to speakers placed around the room. Four to five speakers are incorporated and a surround sound processor is used to create the effect.

SVGA (Super Video Graphics Array) (Video)

Term used to denote resolutions higher than VGA (640 x 480). SVGA computer graphics cards have a resolution of 800 x 600 pixels (480,000 pixels) but may be able to output resolutions of up to 1280 x 1024 and 16 million colors.

S-VHS (Super Video Home Systems) (Video)

A high band video recording process for VHS that increases the picture quality and resolution capabilities.

S-Video (Video)

The composite video signal is separated into the lum (Y, black, and white information) and the chroma (C, color information)

Switch (Data Networking)

A LAN switch is used to efficiently forward messages on a network. In addition to several other features, the advantage of a switch over a hub is that each port has its own dedicated bandwidth.

Switch (General)

A two position wall-mounted device that toggles between the completion or interruption of a circuit between two devices.

System (General)

A group of electrical devices that processes inputs into outputs, allowing for feedback and control. For example, an audio system includes audio source devices, audio distribution and amplification devices, cabling, speakers, and controls.

Systems integration (General)

Having intelligent subsystems that communicate with each other and act upon the information shared.

T

T1 (Communications)

A standard for digital transmission in North America. T1 lines are used for connecting networks across remote distances.

Tamper sensor (Security)

A sensor or switch used to detect the unauthorized tampering with a sensor or contact.

Tap (Communications)

A device inserted into a communications line that allows the line to be shared.

Task lighting (Lighting)

Lighting specifically placed to illuminate an area used for a particular activity.

TCP/IP (Transmission Control Protocol/Internet Protocol) (Data Networking)

The primary protocol suite for networks that use IP addressing.

TDM (time division multiplexing) (Data Networking)

A communications technology that transmits multiple signals over a single communications link, assigning each signal a certain time slice.

Telecommunications (Communications)

Any transmission, emission, or reception of signs, signals, writing, images, and sounds or information of any nature by cable, radio, visual, optical, or other electromagnetic systems.

Terminator (Structured Wiring)

A resistive device that is attached to the end of a cable run. A terminator must match the impedance of the cable to which it is attached.

Thermostat (HVAC)

A set point device used to control the operation of a HVAC system.

Thinnet (Data Networking)

See 10Base2.

TIA (Telecommunications Industry Association) (Standards)

A trade organization that develops and publishes standards for the telecommunications industry.

TIA/EIA (Standards)

Trade associations that collaborate on communications, electronic, and cabling standards. See EIA and TIA.

THX (Video)

A trade name of Lucasfilm Ltd for a movie sound enhancement technology that sets the standard of performance for Dolby sound; originally THX represented Tomlinson Holman Experiment.

Three-way switch (Lighting)

A switch that allows control of power from two or more locations.

Tie-wrap (Structured Wiring)

Plastic or nylon strapping used for binding or bundling cables together or holding them in place. Several styles of tie-wraps are available cinching, hole-mounted, and adhesive closure.

Tip (Communications)

A conductor in a two-wire telephone circuit that is attached to the circuit leading to a positive power source at the telephone company’s CO.

Ton (HVAC)

A cooling system unit of measure that is the equivalent of 12,000 BTUH. Single-family residences typically are equipped with air conditioning units that provide between 2 and 5 tons of cooling.

Topology (General)

The physical or logical pattern of a cabling system. These include star, ring, and bus configurations.

Touch screen (General)

A visual display terminal screen that responds to instructions as the user touches the screen.

Transformer (General)

An electrical device used to reduce or convert the current of an electrical circuit.

Traveller Wires (Lighting)

Wires interconnecting switches when more than one switch can control circuit power independently.

Trip signal (Security)

A signal generated by a sensor or contact and transmitted to an alarm or the security system controller when an out-of-norm condition occurs.

Troffer (Lighting)

A large recessed luminaire that is typically flush-mounted on a ceiling.

Tuner (Audio)

A device used to select signals at a specific radio frequency for amplification and conversion to sound.

Twisted pair (Structured Wiring)

A communications cable made up of one or more wire pairs that have been looped around each other. An increased number of twists in the pair reduce the vulnerability of the wire pair to external interference and signal radiation.

TVSS (Transient Voltage Surge Suppressor) (General)

A device designed to protect connected devices from transient voltages.

Tweeter (Audio

A loudspeaker designed to reproduce high-pitched or treble sounds.

U

UF (underground feeder) cable (Electricity)

A cable designed and rated for underground and outdoor use that is molded into solid plastic.

UHF (ultra high frequency) (Video)

Off-air signal frequencies that carry television channels 14 through 69.

UPS (uninterruptible power supply) (General)

Provides protection against all power disturbances.

Upstream (General)

The transfer of data from an in-house device to elsewhere in the home.

USB (Universal Serial Bus) (Data Networking)

A standard high-speed interface mode for attaching peripheral devices to a PC.

UTP (unshielded twisted-pair) (Structured Wiring)

A type of twisted pair cable that does not include additional shielding to resist EMI or RFI.

UV (ultraviolet) radiation (General)

Invisible light that is composed of electromagnetic radiation with a wavelength of less than 400 nanometers (nm) and greater than 100 nm. UV radiation can be harmful to humans and pets.

USOC (Universal Standards Ordering Code) (Communications)

A standard coding scheme for registered jacks used in telecommunications.

V

Valves (HVAC)

Devices inserted into air ducts that are used to open or restrict the air resistance of a HVAC system.

VHF (very high frequency) (Video)

Off-air signal frequencies that carry television channels 2 through 13.

VHS (video home service) (Video)

The half-inch video cassette format originated and developed by JVC and adopted by different manufacturers.

Volt (General)

Unit of electrical measure that indicates the amount of electrical pressure on a circuit.

Voltage drop (General)

A loss of the power level of a circuit caused by the electrical resistance of the wire.

Voltmeter (General)

An instrument designed to measure a difference in electrical potential in volts.

W

Wall sconce (Lighting)

A decorative wall-mounted light fixture.

Wall washing (Lighting)

A lighting technique used to illuminate a wall.

WAN (wide area network) (Data Networking)

A computer network that interconnects LANs over a large geographic area.

Watt (General)

An electrical unit measure that indicates the amount of electrical power on a circuit.

Wattage (Lighting)

The amount of electricity consumed by a lamp.

Wi-Fi (Wireless Fidelity) (Data Networking)

A certification awarded to IEEE 802.11b wireless networking products that meet the standards developed by WECA (Wireless Ethernet Compatibility Alliance) aimed at ensuring interoperability.

WEP (Wired Equivalent Privacy) (Data networking)

The encryption protocol used to encode data transmitted over an 802.11b wireless network using either 40-bit or 128-bit encryption.

Whole-house controller (General)

A computer-based system dedicated to integrating and managing all home electronics systems.

Whole-house network (General)

A network designed to allow any appliances, electronic products, or systems to communicate directly with any other electronic product or system also on the network, regardless of application.

Wire (Structured Wiring)

A single solid metal conductor or a multiple strand metal conductor used to carry an electrical signal or a current.

Wire clamps (Structured Wiring)

see Cable clamps.

Wire stripper (Structured Wiring)

A tool used to remove portions of insulation from a wire.

Wiremold (Structured Wiring)

A brand name for surface-mounted cable raceway.

Window contact (Security)

A magnetic device used to detect when a window is opened and generate a trip signal to an alarm or the security system controller.

Woofer (Audio)

A loudspeaker that reproduces bass frequency.

X

X-10 (Data Networking, Security)

A popular powerline carrier (PLC) technology that transmits signals over AC power lines to transfer data on a network or to control lights, appliances and other devices.

XLR Connector (General)

A type of audio connector featuring 3 leads; 2 for the signal and one for overall system grounding. A secure connector often found on high quality audio and video equipment, also called a cannon connector.

Z

Zone (General)

A single room, a group of rooms, or an entire house in which automated or centrally located devices are controlled from a single controller. For example, in an audio zone all occupants hear the same audio playback.