Company Information

66-Type Punch-Down Block
A block consisting of four columns of 50 pins each, onto which the 50 wires of the 25-pair group are placed. Each wire is placed in a pin, and then punched into place, stripping the insulation in the process. The pins in columns 1 and 2 are shorted together, and the pins in columns 3 and 4 are shorted together. This creates an input and output side of the block.

To connect the two halves, bridging or shorting clips are used between pins 2 and 3 of any particular row. The 66-Type Punch-Down Block provides easy access to each wire and is used to terminate most twisted-pair cable. Most installed 66-Type Blocks do not support Category 5.

The Institute of Electrical and Electronic Engineers (IEEE) physical layer standard for Ethernet coaxial cable. It specifies the carrier sense multiple accesses with collision detection (CSMA/CD) access method on bus topologies.

An IEEE standard for token ring networks that provides for a ring topology configuration (a closed set of active taps connected by point-to-point links). Access to the ring is granted when a token is received and passed in a logical (and physical) ring sequence between the workstations.

A twisted-pair Ethernet cable standard that conforms to IEEE 802.3 specifications and can carry data at 10 Mbps.

Alternating Current (AC)
An electric current whose direction is periodically reversed. This is the common form of electricity generated in homes and offices. All electronic digital systems use direct current (DC) in their circuits and have built-in power supplies to convert the AC into DC.

American National Standards Institute.

An acronym for Attached Resource Computer Network, a token-passing bus architecture network developed by Datapoint Corporation.

ARCNET, the first local area network technology, has a flexible architecture that allows both star and bus topology networks, or a combination that can be described as a distributed star with branches. ARCNET can use single twisted-pair, coax and duplex fiber optic cabling.

The decreasing of a transmitted signal as it travels along a cable. The longer the cable the more loss there will be. Above a certain amount of loss, the cabling may not transmit network data reliably.

Attenuation to Crosstalk Ratio (ACR)
An indication of how much larger the received signal of a pair is compared to the noise (NEXT) on the same pair.

Maximum information carrying capacity of a channel.

Basic Link
A basic link is a model defined by TSB-67. A basic link is similar to what an installer might work with - including the wall plate, horizontal wiring and first cross connection. It is intended to be used by system designers and users of data telecommunications systems to verify the performance of permanently installed cabling.

A basic link consists of up to 90 meters of horizontal cabling, a connection at each end, up to 2 meters of test equipment cord from the main unit of the field tester to the local connection, and up to 2 meters of test equipment cord from the remote connection to the remote unit of the field tester.

Comite Europeen de Normalization Electrotechnique

An automated test process that verifies that test results meet established standards requirements.

All elements of the communications link connecting a DTE (typically a PC or server) to a hub in the wiring closet. Includes fiber cabling, patch cords, connections, and splices if any. A channel is a model defined by TSB-67.

It is similar to what a user works with to transmit information between a personal computer and its hub, or concentrator.

A channel includes up to 90 meters of horizontal cable, a work area equipment cord, a telecommunications outlet/connector, an optional transition connection close to the work area, and two cross-connect connections in the telecommunications closet.

According to the TSB-67, the total length of equipment cords, patch cords and jumpers shall not exceed 10 meters. It is important to note that the connections to the equipment at each end of the channel are not included in the channel definition.

A protective layer made of glass or plastic, which surrounds the core. The cladding has a lower index of refraction than the core, which helps keep light in the core.

The center of a fiber optic cable usually made of extremely clear glass or plastic, through which the light travels.

Electronic Industries Association (EIA)
An organization of manufacturers of electronic parts and systems. The EIA sets such standards as the EIA-232 interface specification.

Electromagnetic Interference
An unwanted signal that enters the transmission line from fluorescent lights, fan motors, etc. See also RF Interference.

Equal Level Far End Crosstalk. This is far end crosstalk adjusted for attenuation. It can be thought of as far end ACR.

Fiber Data Distributed Interface

Hertz (Hz)
The frequency of electrical vibrations (cycles) per second. One Hz equals one cycle per second.

IDC-Type Punch-Down Block
A twisted-pair wiring panel in which each wire is placed in a pin, and then punched into place, stripping the insulation in the process.

International Electro-technical Commission Institute of Electrical and Electronic Engineers (IEEE). A membership organization, including engineers, scientists and students in electronics and allied fields, that is involved with setting standards for the computer and communications field.

The resistance to the flow of alternating current in a circuit.

International Standards Organization

Local Area Network (LAN)
A communications network serving multiple users within a confined geographical area (as in the same building or group of adjacent buildings).

It usually refers to the interconnection of personal computers. Shared data is stored in a high performance PC called a fileserver, which serves as a remote disk drive to all network users. Users may also share printers, modems and other peripheral devices.

The shorting together of wires in a connector so that a signal sent along the wire returns to its place of origin.

Megahertz (MHz)
One million cycles per second. See Hertz (Hz).

1 millionth of a meter

Multimedia network
A network that allows access to Integrated Voice and Data (IVD) over standard unshielded telephone twisted-pair wiring. Multimedia LANs use existing wiring to carry both voice and medium-to-high speed data in typical office environments.

Fiber optic cabling with a wider core (typically 50 or 62.5 microns) that allows light to travel in multiple paths, such that it is reflected back from the cladding back into the core as it travels down the core.

Near End Crosstalk (NEXT)
The interference measured on a wire adjacent to the wire on which the signal is being sent. Near end crosstalk measurements show the amount of signal leaking when measured close to the signal generation point.

If the crosstalk coupling across at the near end is great enough, it can interfere with signals coming from a remote point, which are diminishing as they reach the same spot.

Any extraneous signal that invades the transmission of electrical pulses or frequencies along a cable. Noise is measured as impulse or Root-Mean-Square (RMS).

Nominal Velocity of Propagation (NVP)
The speed of data transmission along a cable relative to the speed of light in a vacuum.

Optical Link Budget

Optical Time Domain Reflectometer. A sophisticated fiber test tool that locates fiber breaks, and can determine loss per connection, splice, or segment.

Patch cable (Test Cable)
A short, flexible cable terminated at both ends that are used to interconnect LAN equipment.

One of the male leads on a multiple line plug, such as an RJ-45 connector or an EIA-232 connector.

Plenum cable
Cable certified to be fire resistant and to produce a minimum of smoke. It can be installed in the space between the false ceiling and the floor or ceiling above, called the plenum.

Punch-Down Block
A central termination point for twisted-pair cable. Each wire is placed in a pin, and then punched into place, stripping the insulation in the process. See also 66-Type Punch-Down Block and IDC- Type Punch-Down Block.

A property of a conductor, which resists or opposes the flow of current in an electronic circuit.

Return Loss
This is a measure of the overall uniformity of a link's impedance relative to 100 ohms.

RF Interference
An unwanted signal that enters the transmission line from radio and television transmitters. With this type of interference, the cable acts as an antenna. See also Electromagnetic Interference and Noise.

Screened Twisted-Pair (ScTP) cable
Four pair UTP, with a single foil or braided screen surrounding all four pairs in order to minimize EMI radiation or susceptibility. Screened twisted pair is sometimes called Foil Twisted Pair (FTP).

Screened/Shielded Twisted Pair (SSTP)
Four pair cabling, with each pair having its own individual shield, in addition to an overall shield surrounding all four pairs. SSTP offers similar performance to Type 1 STP except with 4 pairs (rather than 2) and in a 100-ohm impedance (rather than 150).

An insulating material used with coax or twisted-pair cable to reduce electrical interference.

Shielded Twisted Pair (STP)
Two pair cabling, with both pairs having its own individual shield, in addition to an overall shield surrounding both pairs. STP is most familiar to LAN users as the heavy black IBM Type 1 cabling found in token ring networks.

Fiber optic cabling with a narrow core (8-9 microns) that only allows light to travel in one path (i.e. one mode).

Time Domain NEXT (TDNXTSM)
A totally new concept in cable troubleshooting offers unique advantages:

  1. True NEXT vs. length pinpoints causes of NEXT failures can clearly and accurately identify whether connectors or cable are the cause of the failure.
  2. Magnitude scaling (Cat 5, 5E, 6) auto-adjusts for relative NEXT of different category links.
  3. When used with S-Band Technology (patent pending), creates foolproof diagnostic capability.

Time Domain Return Loss (TDRLSM)
Measures return loss versus length and delivers benefits:

  1. True return loss versus length identifies sources of RL patent pending S-Band technology for precision faultfinding.
  2. Can easily tell if connections meet Cat 5, Cat 5E, Cat 6, or Cat 7 requirements

Telecommunications Industry Association

Time Domain Reflectometry (TDR)
A diagnostic technology in which a pulse of known amplitude and duration is sent along a cable. When an open or short is detected, a pulse reflects back to the device generating the signal.

The device then measures how long the round trip took and converts this to distance using the cable's NVP.

Token Ring Network
A physical ring network topology. On a token ring network, data moves around the entire ring, from one workstation to the next, eventually receiving the transmitted information back after it completes one round trip around the ring.

The token, a specific bit sequence that circulates around the nodes, gives permission to transmit.

Twisted-Pair cable
Cable in which two wires are wrapped (or twisted) around each other between two and 12 times per foot of length. Most twisted-pair cabling contains either four or 25 pairs of wires.

Unshielded Twisted-Pair (UTP) cable A common type of twisted-pair cable that does not have a shield wrapped around the wires.

Wire closet
An area in a building in which punch-down blocks are centralized; a central termination area for network or telephone cabling.