C

A structured, procedural programming language

C/I

Carrier-to-Interface Ratio

C/N

Carrier-to-Noise Ratio

CA

Conditional Access/Authority

CAC

Carrier Access Code

CAI

Common Air Interface

CALC

Customer Access Line Charge

CALEA

Communications Assistance for Law Enforcement Act

Caller ID

Calling Number Identification

CAMEL

Customized Application for Mobile network Enhanced Logic

CAN

Campus Area Network

CAP

Carrierless Amplitude and Phase Modulation

CAP

Competitive Access Provider

CAPI

Common ISDN API

CARS

Cable Television Relay Service

CAS

Channel-Association Relay Service

CAT5

Category 5 Cabling

CAT5e

Category 5e (extended) Cabling

CAT6

Category 6 Cabling

CATV

Community Antenna Television

CAU

Controller Access Unit

CBCH

Cell Broadcast Channel

CBR

Committed Bit Rate; Constant Bit Rate

CBT

Core-Based Trees

CC

Common Carrier; Cost Component; Cross Connection

CCCH

Common Control Channel

CCDF

Complementary Cumulative Distribution Function

CCH

Control Channel

CCIS

Common Channel Interoffice Signaling

CCITT

Comité Consultatif International de Télégraphie, or International Telephone and Telegraph Consultative Committee, Now called ITU

CCLC

Carrier Common Line Charge

CCS

Centi Call Seconds

CCS

Common Channel Signaling

CCSA

Common Control Switching Arrangement

CCTV

Closed Circuit Television

CDDI

Copper Distribution Data Interface

CDF

Channel Definition Format

CDF

Cumulative Distribution Function

CDG

CDMA Development Group

CDM

Code Division Multiplex

CDMA

Code Division Multiple Access

CDMA20001xEV

The EV means “Evolution”

CDMA20001xEV-DO

The 1xEv-DoO means “1x-Evoltion-Data Optimized” (or Evolution- Data Only)

CDMA20001xEV-DV

The EV-DV means “1xEvolution-Data and Voice.”

CDMA20001xRTT

The RTT means single carrier Radio Transmission Technology

CDMA3Xrtt

Code Division Multiple Access 3-Carrier Radio Transmission Technology

CDMAOne®

Code Division Multiple Access One

CDP

Code Domain Power

CDPD

Cellular Domain Power

CDR

Call Detail Record

CD-ROM

Compact Disc, Read-Only-Memory

CDV

Cell Delay Variation

CDVCC

Coded Digital Verification Color Code

CDVT

Cell Delay Variation Tolerance

CE

Conditioning Equipment

CELP

Code-Book Excited Linear Predictive

CEN

Comite Europeen De Normalisation

CEN/ISSS

European Committee for Standardization/ Information Society Standardization System

CENELEC

Comite European De Normalisantion Electrique; The European Committee for Electrotechnical Standardization

CEPT

Committee of European Posts and Telephones

CERN

European Organization for Nuclear Research

CES

Circuit Emulation Service

CES-IWF

CES Internetworking Function

CEV

Controlled Environmental Vault

CFA

Carrier Facility Assignment

CFA

Carrier Failure Alarm

CFIN

Carrier Frequency Identification Number

CFTC

Copper From The Curb

CGA

Carrier Group Alarm

CGI

Common Gateway Interface

CGMP

Cisco Group Multicast Protocol

CGSA

Cellular Geographic Services Area

CHAP

Challenge Handshake Authentication Protocol

CHTML

Compact HTML

CI

Customer Installation

CIC

Carrier Identification Code

CICS

Customer Identification Code

CID

Customer Information Control System

CIDR

Channel Identifier

CIF

Common Intermediate Format

CIR

Committed Information Rate

CLASS

Custom Local Area Signaling Services

CLDC

Connected Limited Device Configuration

CLE

Customer Located Equipment

CLEC

Competitive Local Exchange Carrier

CLEI

Common Language Equipment Identifier

CLI

Command Line Interface

CLI, CLID

Calling Line Identification

CLLI

Common Location Language Identifier

CLP

Cell Loss Priority

CMA

Construction and Maintenance Agreement

CMR

Cellular Mobile Radio

CMRS

Commercial Mobile Radio Service

CMS

Call Management Service

CMTS

Cable Modem Termination System

CNG

Comfort Noise Generation

CNI

Communication Network Intelligence

CNI, CNID

Calling Number Identification

CO

Central Office

COAM

Customer Owned And Maintained

COAX

Coaxial Cable

COCOT

Customer Owned Coin Operated Telephone

CODEC

Compressor/Decompressor

.com

“Company,” one of the Internet’s top-level domain names

COM

Component Object Model

CompTIA

Computing Technology Industry Association

COMSAT

Communications Satellite Corporation

CONNACK

Connect Acknowledgement

COP

Character Oriented Protocol

CORBA

Common Object Request Broker Architecture

COS

Class of Service

COT

Central Office Terminal

COW

Cell Site On Wheels

CP

Call-Progress Tones

CPD

Call Processing Data

CPE

Customer Premise Equipment

CP-IWF

Customer Premises Interworking Function

CPL

Commercial Private Line

CPL

Call Processing Language

CPM

Continuous Phase Modulation

CPN

Calling Party Number

CPNI

Calling Party Number Identification

CPSB

CompactPCI Packet Switching Backplane

CPU

Central Processing Unit

CR

Custom Record

CRC

Cyclic Redundancy Check/Code

CREDFACS

Conduit, Raceway, Equipment Ducts, and Facilities

CRIS

Customer Record Information System

CRM

Customer Relationship Management

CRTP

Compressed Real-Time Transmission Protocol

CS

Calling Seconds; Carrier System

CSA

Carrier Service Area

CS-ACELP

Conjugate Structure Algebraic Code Excited Linear Prediction

CSD

Circuit-Switch Data

CSMA

Carrier Sense Multiple Access

CSMA/CD

Carrier Sense Multiple with Collision Detection

CSPDN

Circuit Switch Public Data Network

CSTA

Computer Supported Telephony Application

CSU

Channel Service Unit

CSU/DSU

Channel Service Unit/ Data Service Unit

CSV

Circuit-Switch Voice

CT

Computer Telephony

CT

Cross Talk (also XT)

CT2

Cordless Telephone 2. Also written CT-2

CT3

See DECT

CT3

See DCT 900

CTD

Cell Transfer Delay

CTI

Computer Telephone Intergration

CTIA

Cellular Telecommunications and Internet Association

CTS

Clear To Send

CTS

Cordless Telephone System

CTT

Click-to-Talk

CTTC

Copper To The Curb

CU

Control Unit

CUT

Coordinated Universal Time

CW

Continuous Wave

CXR

Carrier

Cable

Either a stranded conductor with or without insulation and other coverings (single-conductor cable), or a combination of conductors insulated from one another (multiple-conductor cable).

Cable Assembly

A cable with plugs or connectors on each end.

Cable Clamp

A device used to give mechanical support to the wire bundle or cable at the rear or a plug or receptacle.

Cable Fiber Optic

A jacketed fiber in a form that can transmit optical signals.

Cable Terminal

In power work, a device that seals the end of a cable and provides insulated egress for the conductors, Also known as a pot head or an end bell.

Cantilevered Contact

A spring contact in which the contact force is provided by one or more cantilevered springs. It permits more uniform contact pressure and is used almost exclusively in PC board connectors.

Capacitance

That property of a system of conductors and dielectrics that permits the storage of electricity when potential difference exists between the conductors. Its value is expressed as the ratio of quantity of electricity to a potential difference. A capacitance value is always positive.

Captive Device

A multi-part fastener, usually screw-type, which has components that are retained without separation when loosened from its base assembly.

Card Cages/Racks

Containers that provide compact packaging of printed boards. Variously sized, they hold varying numbers or cards; allow heat dissipation; and, in sophisticated models, incorporate a ground plane with connectors and DIP devices to take advantage of highly automated back panel wiring techniques.

Card Edge Connector

A connector that mates with printed wiring leads running to the edge of a PC board. Also called Edgeboard Connector.

Card Guide

A plastic or metal support for printed boards. It relieves the stress on connector contacts, makes insertion into and extraction from the connector easier and eliminates the possibility of twisting the board.

Card Slot

The lengthwise opening in a printed circuit edge connector that receives the PC board.

Castellation

Metallized feature that is recessed on the edge of a chip carrier used to interconnect conducting surfaces or planes within or on the chip carrier.

Catalyst

A substance that initiates and/or accelerates a chemical reaction but normally does not enter into the reaction.

Cathode

The negative pole of plating apparatus at which positively charged ions leave the plating solution. A metal is deposited on the cathode. See Anode.

Cavity

The lengthwise opening in a printed circuit edge connector that receives the printed circuit board.

Center-to-Center Distance

See Pitch.

Center-to-Center Spacing

The nominal distance between the centers or adjacent features on any single layer of a PC board, component package, or cable connector. See Pitch.

Certification

Verification that specified testing has been performed and required parameter values have been attained.

Chamfer

Angle on the inside edge or the barrel entrance of a connector that permits easier insertion of the cable into the barrel.

Characteristic Impedance

The ratio of voltage to current in a propagating wave, ie., the impedance that is offered to this wave at any point of the line. In printed wiring, its value depends on the width of the conductor, the distance from the conductor to ground planets) and the dielectric constant or the media between them.

Chip

The unpackaged and norm any leadless form of an IC semiconductor, either passive or active, discrete or integrated. Chip components have metallized terminations for interconnecting to the substrate.

Chip Carrier

A low profile surface mount comge, usually square, having a semiconductor chip cavity or mounting area that is a large portion or the package size and having external connections on all four of its sides. The package may have leads or may be leadless, with pads instead of leads.

Circuit

(1) A complete path or electron flow from a negative terminal of a voltage source through a conductor and back to the positive terminal. (2) The interconnection of a number or elements or parts to accomplish a desired function.

Circuit Element

A basic constituent or a circuit, exclusive or interconnection.

Circuit Verifier

An assembly that electrically stimulates an item to be tested and monitors for proper response. This includes shorts and opens testing as well as functional diagnostic testing. Also called – Analyzer, Test Set, and Tester.

Circumferential Crimp

Final configuration of a terminal barrel made when crimping dies completely surround the barrel and form symmetrical indentations.

Circumferential Separation

A crack in the plating extending around the entire circumference of a plated through-hole, in the solder fillet around the lead wire, in the solder fillet around an eyelet or at the interface between a solder fillet and a land.

Clad

A base material covered by a relatively thin layer or a sheet of metal foil that has been bonded to one or both of its sides.

Cladding

(1) A method of applying a layer of metal over another metal whereby the junction of the two metals is continuously welded. (2) A low refractive index material that surrounds the core and provides optical insulation and protection to the core. Optical cladding promotes total internal reflection for the propagation of light in a fiber.

Cladding Mode

A mode that is confined by virtue of a lower index medium surrounding the cladding. See also: Mode.

Cladding Mode Stripper

A device that encourages the conversion of cladding modes to radiation modes; as a result of its use, cladding rays are stripped from the fiber.

Clamping Screw

One element of a clamping system that is used in terminal blocks. When the screw is tightened, counteraction forces the damping yoke upward, compressing the conductor firmly against the current bar. See Yoke; Current Bar.

Clinched-Wire Through Connection

A connection made by a wire that is passed through a hole in a PC board, subsequently formed or clinched in contact with the conductive pattern on each side of the board and soldered.

Clip Terminal

The point at which the hook-up wire is clipped against the connector post.

Clocking

The arrangement of connector inserts, jack-screws, polarizing pins/sockets, keys/keyways or housing configurations to prevent the mismating or crossmating of connectors. Also called Polarization.

Closed Barrel Terminal

A wire barrel, terminal configuration available in strip form, or as loose pieces. See Open Barrel Terminal; Brazed Terminal.

Closed Base

A design for terminal junction blocks which is useful in applications requiring single point circuit terminations or circuit completion via tip mounted, single and two-sided quick connects.

Closed End Splice

An insulated splice in which two or more wires overlap and enter the splice from the same end of the barrel.

Closed Entry

A design that limits the size of mating parts to a specified dimension. Usually used in reference to pin and socket contacts.

Closed Entry Contact

A female contact designed to prevent the entry of a pin or probing device having a cross-sectional dimension (diameter) greater than the mating pin.

Coat

To cover with a finishing, protecting or enclosing layer of any compound.

Coaxial Cable

A high-bandwidth cable consisting of two concentric cylindrical conductors with a common axis that is used for high-speed data communication and video signals.

Coefficient of Thermal Expansion (CTE)

The linear dimensional change of a material, per unit change in temperature, usually expressed as parts per million or as inch per inch, per degrees centigrade.

Coil Form Terminals

Used on small transformer coils to connect coil wires. Terminals are attached to coil base or collar.

Cold Flow

Permanent deformation of insulation due to mechanical forces, without the aid of heat softening of the insuli1ting material.

Cold Short

The brittle condition in a metal at temperatures below the recrystallization temperature.

Cold Weld

A weld achieved by pressure only, i.e., without electrical current or elevated temperature.

Cold Work

Embrittlement of metal due to repeated flexing action.

Color Coding

Marking a terminal or contact with color to aid in identification and selection of wire size and crimping tool.

Commutator Fusing

Method of joining lead wires, which are usually magnet wires, of a universal or DC electric motor's armature to the commutator.

Complete Solder Joint

A soldered connection between a wire lead and a terminal area where the solder wets and forms a void-free fillet between the wire lead and the complete terminal area.

Component Density

The quantity of components on a PC board per unit area.

Component Hole

A hole used for the attachment and electrical connection of component terminations, including pins and wires, to the PC board.

Component Lead

The solid or stranded wire or formed conductor that extends from a component and serves as a readily formable mechanical or electrical connection or both.

Composite

A homogenous material that differs from alloys by retaining the characteristics of individual components that are so incorporated into the composite as to take advantage of their attributes, not their shortcomings. A material that consists of a strengthening phase in the form of particulates, whiskers, short, discontinuous or continuous fibers embedded in another phase called a matrix. Composite materials are usually divided into three broad groups identified by the matrix material - resin, metal and ceramic.

Compression Connector

Connector crimped by an externally applied force; the conductor is also crimped by such force inside the tube-like connector body. Compression connectors are in very intimate contact with the two ends of the conductors being spliced.

Compressive Strength

The maximum compressive stress a materia1 is capable of sustaining. For materials that do not fail by a shattering fracture, the value is arbitrary, depending on the distortion allowed.

Concentricity

In a wire or cable, the measurement of the location of the center of the conductor with respect to the geometric center of the surrounding insulation.

Conductance

The reciprocal of resistance. lt is the ratio of current passing through a material to the potential difference at its ends.

Conductive Contaminant Growth

The bridging of circuits by conductive salts. This contamination develops from plating and etching residues as well as from flux residues.

Conductive Pattern

The configuration or design of the conductive material on the base material. Includes conductors, lands and through connections when these connections are an integral part of the manufacturing process, such as additive.

Conductivity

The ability of a material to conduct electric current. It is expressed in terms of the current per unit of applied voltage. It is the reciprocal of resistivity.

Conductor

A wire or combination of wires not insulated from one another, suitable for carrying electric current.

Conductor Spacing

The distance between adjacent edges (not centerline to centerline) of isolated conductive patterns in a conductor layer.

Conductor Stop

A device on a terminal splice, contact or tool used to prevent excessive extension of the conductor beyond the conductor barrel.

Configuration

Arrangement of contacts in a multiple-contact connector.

Confined Crescent (CC) Crimp

A crimp that remains within the OD of the original barrel. It is usually identified by two crescent-shaped forms on the top and bottom of the wire barrel crimp.

Confined Time

(I) In a telephone system, the time duration of a connection between two points. (2) In a computer-based dati1 communications assembly, the switching time required to set up a connection between two terminal points.

Conformal Coating

An insulating protective coating that conforms to the configuration of the object coated, applied to the completed PC board assembly.

Connection

That part of a circuit that has negligible impedance and that joins components, devices, etc., together.

Connection Diagram

A pattern illustrating the connections needed to place an electronic system in operation when such system includes one or more assemblies, power supplies and devices controlled.

Connector

(1) A device providing electrical connection/ disconnections. It consists of a mi1ting plug and receptacle. Various types of connectors include DIP, card edge, two-piece, hermaphroditic and wire-wrapping configurations. Multiple contact connectors join two or more conductors with others in one mechanical assembly. (2) A junction that allows an optical fiber or cable to be repeatedly connected or disconnected to a device such as a source or detector.

Connector Area

That portion of printed wiring used for the purpose of providing external electrical connections.

Connector Assembly

A mated plug and receptacle.

Connector Block

Connector housing.

Connector Discontinuity

An ohmic change in contact resistance.

Connector Housing

Insulating material, usually plastic, that encapsulates contacts. Once pins and sockets are inserted into the housing, the assembly is called a connector. (Also called a block.)

Connector Insert

For connectors with metal shells, the insert holds contacts in proper arrangement while electrically insulating them from each other and from the shell.

Connector Insertion Loss

The loss of power due to insertion of a mated connector onto a cable.

Connector Module

A family of connector inserts that are uniform in external dimension, but that have the ability of each accepting different types of contacts or having different contact densities or configurations.

Connector Patch

Center-to-center measurement of conductive layers.

Connector Set

Two or more separate plug and receptacle connectors designed to be mated together.

Connector Shell

The case that encloses the connector insert and contact assembly. Shells of mating connectors can protect projecting contacts an provide proper alignment.

Constriction Resistance

The portion of the contact resistance that is due to the contact to circuit board interface.

Contact

The conducting part of a connector that acts with another such part to complete or break a circuit; contacts provide a separable through connection in a cable-to-cable, cable-to-box or box-to-box situation. Types include:

Bellows Gontact: A contact that is a flat spring folded to provide a uniform spring rate over the full tolerance range of the mating unit.

Bifurcated Gontact: A contact (usually a flat spring) which is slotted lengthwise to provide redundant points of contact.

Blade Gontact: Used in multiple contact connectors, a flat male contact designed to mate with a tuning fork or a flat formed female contact.

Buff Gontact: A mating contact configuration in which the mating surfaces engage end-to-end without overlap, with their axes in alignment. This engagement is usually under spring pressure with the ends designed to provide optimum surface contact.

Bulton-Hook Contact: A contact with a curved, hooklike termination, often located at the rear of hermetic headers to facilitate soldering or de-soldering of leads.

Closed Entry Contact: A female contact designed to prevent the entry of a pin or probing device that has a cross-sectional dirnensioll (diameter) greater than that of the mating pin.

Crimp Contact: A contact with a back portion in the shape of a hollow cylinder to allow it to accept a wire. After a bare wire is inserted, a tool is applied to crimp the contact metal firmly against the wire. A crimp contact often is referred to as a solderless contact.

Dressed Contact: A contact with a permanently attached locking spring member.

Fixed Contact: A contact that is permanently locked, cemented or imbedded in the connector body, housing insulator during molding.

HermaphroditipContact: A contact in which both mating elements are precisely alike at their mating face.

Nude Contact: A contact with a locking member that remains in the insert at all times.

Open Entry Contact: A female-opening contact unprotected from possible damage or distortion from a test probe or other wedging device.

Pin Contact: A male-type contact, usually designed to mate with a socket (female) contact, and normally connected to the "dead" side of a circuit.

Press Fit Contact: Either a solid pin or a pin having a compliant member that makes an interference connection with a through-hole on a PG board. The pressure developed between interconnecting surfaces is sufficient to provide gas-tight electrical reliability without the use of solder.

Rear Release Contact: A contact that is released and removed from the rear (wire side) of the connector. The removal tool engages the contact from the rear and pulls the contact out of the connector contact retainer.

Removable Contact: A contact that can be mechanically joined to or removed from an insert. Usually, special tools are required to lock the contact in place or remove it for repair or replacement.

Screw-Machined Contact: A precision machined goblet-shaped brass receptacle with an insert having 3, 4 or 6 contact tines that mate with the male contact.

Sheet Metal Contact: A contact made by stamping and bending sheet metal rather than by the machining of metal stock. Available in a wide variety of configurations, such contacts are usually less expensive than machined contacts.

Solder Contact: A contact having a cup, hollow cylinder, eyelet or hook to accept a wire foldered termination.

Spade Contact: A contact with fork-shaped female members designed to dovetail with spade-shaped male members. Proper alignment in some types is very critical if good conductivity is to be achieved.

Strip Contact: One of a continuous length of formed contacts for use in an automatic installation machine.

Taper Pin Contact: A pin-type contact having a tapered end designed to be inserted into a tapered hole for a separable (changeable) termination.

Two-Piece Contact: A contact made of two or more separate parts joined by swedging, brazing or other means of fastening to form a single contact. This type provides the mechanical advantages of two metals but also has the inherent electrical disadvantage of difference in conductivity.

Contact Alignment

Defines the overall side play that contacts shall have within the insert cavity so as to permit self-alignment of mated contacts. Sometimes referred to as amount of contact float.

Contact Area

Area in contact between two conductors, or a conductor and a connector:, permitting flow of electrical current.

Contact Arrangement

The number, spacing and pattern of contacts in a connector.

Contact Back Wipe

An actuated contact surface where a contact travels on the surface of its mating contact during the actuation cycle, then moves back to a clean wiped surface at the completion of the actuation cycle.

Contact Cavity

A defined hole in the connector insert into which the contacts must fit.

Contact Chatter

Connector ohmic discontinuities.

Contact Durability

Endurance measured by the number of insertion and withdrawal cycles that a connector withstands remaining within its specified performance levels.

Contact Engaging and Separating Force

Force needed to either engage or separate pins and socket contacts when they and out of connector inserts. Values are generally established for maximum and minimum forces.

Contact, Female

A contact located in an insert or body in such a manner that mating contact is inserted into the unit. If is similar in function to a socket contact.

Contact Inspection Hole

A hole in cylindrical rear portion of a contact used to check the depth to which a wire has been inserted.

Contact Length

Length of travel made by one contact in contact with another during assembly or disassembly of a connector. (Sometimes called Contact Mating Length. Also see Wiping Action.)

Contact, Male

A contact located in all insert or body in such a manner that the mating portion extends into the female contact. lt is similar in function to a pin contact.

Contact Plating

Plated-on metal applied to the base contact metal to provide the required contact resistance and / or wear-resistance.

Contact Positions

In most connectors, the maximum number of contacts that can be actively engaged. In edge connectors, the number of contact positions along the length of the connector, as opposed to the total number of contacts. (See Readout.)

Contact Pressure

Force that mating surfaces exert against each other.

Contact Resistance

Maximum permitted electrical resistance of pin and socket contacts when assembled in a connector under typical service use.

Contact Retainer

A device either on the contact or in the insert to retain the contact.

Contact Retention

The minimum axial load in either direction that a contact must withstand while remaining firmly fixed in its normal position within the connector insert or housing.

Contact Shoulder

The flanged portion of the contact that limits its travel into the insert.

Contact Size

Defines the largest size wire that can be used with the specific contact. By specification dimensioning, it also defines the diameter of the engagement end of the pin.

Contact Spacing

The distance between the Centerlines of adjacent contact areas.

Contact Spring

The spring placed inside the socket-type contact to force the pin into a position of positive intimate contact.

Contact Wipe

The area over which mating contact surfaces are touching during engagement and separation. (See Wiping Action.)

Continuity

A continuous path for the flow of current in an electrical circuit.

Continuous Current Rating

The designated rms alternating or direct current that the connector can carry continuously under specified conditions.

Control Cable

A multiconductor cable made for operation in control or signal circuits, usually flexible, relatively small in size, and with relatively small current ratings.

Controlled Impedance Cable

Package of two or more insulated conductors where impedance measurement between respective conductors is kept essentially constant throughout entire length.

Controlled Part

Any item that requires specialized manufacturing and procurement techniques.

Convection

A conveying or transference of heat or electricity by moving particles of matter.

Convection

A definite formatting method used in electronic diagrams to present the clearest picture of the circuit function.

Copper and Copper Alloys

Copper is the most widely used electrical conductor in wires and cables; copper and its alloys are used extensively for contacts, fuse clips, terminals and connectors. On a volume basis, copper has the best conductivity of the common (non-precious) metals. Copper and copper alloys offer excellent corrosion resistance, high thermal conductivity and ease of fabricating, joining and forming.

Cordwood Module

A module formed by bundling or stacking parts between a pair of end plates and interconnecting them into circuits by welding or soldering leads together.

Core

The light conducting portion of a fiber defined by its high refractive index. The core is normally the center of a fiber bounded by concentric cladding.

Corrosion

The destruction of the surface of a metal by chemical reaction.

Corrosive Fluxes

Fluxes, consisting of inorganic acids and salts, are generally required where the condition of a surface is well below the ideal for rapid wetting by molten solder. (Also called Acid Fluxes.)

Coupler

(1) A component that transfers energy from one circuit to another. (2) An optical component that interconnects three or more optical conductors. (3) A device that distributes optical power among two or more ports or concentrates optical power from two or more fibers into a single port. Couplers may be active or passive.

Coupling

See Bayonet Coupling.

Coupling Efficiency

The fraction of available output from a radiant source, which is coupled and transmitted by an optical fiber. The coupling efficiency for a Lambertian radiator is usually equal to the sin20 max. for the optical fiber being used. (See also: Lambertian Radiator.)

Coupling Loss

(1) Non-preferred term for connector insertion loss. (2) The power loss suffered when coupling light from one optical device to another.

Coupling Ring

A device used on cylindrical connectors to lock plug and receptacle together. It mayor may not give mechanical advantage to the operator during the mating operation.

Coupling Torque

Force required to rotate a coupling ring or jackscrew when engaging a mating pair of connectors.

Cover

An item specifically designed to cover the mating end of a connector for mechanical and/or environmental protection.

Creep

The dimensional change with time of a material under load, following the initial instantaneous elastic deformation; the time-dependent part of strain resulting from force. Creep at room temperature is sometimes called "cold flow."

Creep Distance

Shortest distance on the surface of an insulator separating two electrically conductive surfaces.

Creep Tests

Tests on soldered joints performed by stressing the joint at a specific load to determine the rate of strain obtained.

Creepage

Conduction of electricity across the surface of a dielectric.

Crimp

Final configuration of a terminal barrel formed by the compression of terminal barrel and wire.

Crimp Contact

A contact with a back portion that is a hollow cylinder to allow it to accept a wire. After a bared wire is inserted, a swedging tool is applied to crimp the contact metal firmly against the wire. (A crimp contact often is referred to as a Solderless Contact.)

Crimp Terminal

A point at which the bared portion of the hook-up wire is crimped to either the contact or a tab or pin that mates with the contact terminal.

Crimp Termination

Connection in which a metal sleeve is secured to a conductor by mechanically crimping the sleeve with pliers, presses or automated crimping machines. Splices, terminals and multi-contact connectors arc typical terminating devices attached by crimping. Suitable for all wire types.

Crimper

That part of the crimping die, usually the moving part, that indents or compresses the terminal barrels. Also called Indenter.

Crimping Chamber

Area of a crimping tool, formed by mating the anvil (nest) and crimper (indentor), in which a contact or terminal is crimped.

Crimping Die

Portion of the crimping tool that shapes the crimp.

Crimping Tool

Mechanism used for crimping.

Critical Angle

The smallest angle at which a meridional ray may be totally reflected within at the core-cladding interface. When light propagates in a homogeneous medium or relatively high refractive index (n1) onto an interface with a homogeneous material of lower index (n2), the critical angle is defined by sin -1 (n1/n2).

Critical Temperature

The maximum temperature at which superconductivity occurs in a substance.

Cross Connector

Connector that joins two branch conductors to the main conductor. The branch conductors are opposite to each other and perpendicular to the main conductor.

Cross Crimp

A crimp that shapes the terminal by pressing the top and bottom of the terminal barrel without confining the sides.

Cross Linking

When chemical links set up between molecular chains, the plastic is said to be cross-linked. In thermosets, cross linking makes one infusible super-molecule of all the chains, contributing to strength, rigidity and high-temperature resistance. Thermoplastics (e.g., polyethylene) can also be cross-linked (e.g., by irradiation or chemically through formulation) to produce three-dimensional structures that are thermoset in nature and offer improved tensile strength and stress-crack resistance.

Cross Modulation

A form of signal distortion in which modulation from one or more RF carrier(s) is imposed on another carrier.

Crossed Wire

Technique of measuring contact resistance that eliminates all resistances but the resistance of the contact point.

Crosshatching

The breaking of large conductive areas by the use of a pattern of voids in the conductive material.

Crossover

Point at which two conductors that are insulated from each other cross.

Crosstalk

(1) Undesired electrical currents in conductors caused by electromagnetic or electrostatic•coupling from other conductors or hom external sources. Also called Spurious Signal. (2) Leakage of optical power from one optical conductor to another. (3) The introduction of signals from one communication channel into another, which often happens when cables cross each other.

Cure

To change the physical properties of a material (usually from a liquid to a solid) by chemical reaction, by the action of heat and catalysts, alone or in combination, with or without pressure.

Current

A movement of electrons, positive ions, negative ions or holes; the rate of transfer of electricity from one point to another. Current is usually measured in amperes.

Current Bar

One element of a clamping system that is designed for maximum contact area. Some current bars contain longi¬tudinal grooves that cut through the oxide skin of the conductor to provide linear con¬tact lines. (See Yoke; Clamping Screw.)

Current Carrying Capacity

The maximum current an insulated conductor can safely carry without exceeding its insulation and jacket temperature limitations.

Current Density

The maximum current that can be carried by a superconductor.

Current Penetration

The depth a current of a given frequency will penetrate into the surface of a conductor carrying the current.

Current Rating

Maximum current that a device is designed to conduct for a specified time at a specified operating temperature.

Cutout

The hole, usually round or rectangular, cut in a metal panel for mounting a connector. May include holes for mounting screws or bolts.