This article needs additional citations for verification .(May 2022) |
A 66 block is a type of punch-down block used to connect sets of wires in a telephone system. They have been manufactured in four common configurations, A, B, E and M. [lower-alpha 1] A and B styles have the clip rows on 0.25" centers while E and M have the clip rows on 0.20" centers. The A blocks have 25 slotted holes on the left side for position the incoming building cable with a 50 slot fanning strip on the right side for distribution cables. They have been obsolete for many years. The B & M styles have 50 slot fanning strip on both sides. The B style is used mainly in distribution panels where several destinations (often 1A2 key telephones) need to connect to the same source. The M blocks are often used to connect a single instrument to such a distribution block. The E style has 5 columns of 10 2 clips rows and are used for transitioning from the 25 pair distribution cable to a 25 pair RJ21 style female ribbon connector.
66 blocks are designed to terminate 20 through 26 AWG insulated solid copper wire or 18 & 19 gauge skinned solid copper wire. The 66 series connecting block, introduced in the Bell System in 1962, was the first terminating device with insulation displacement connector technology. The term 66 block reflects its Western Electric model number.
The 25-pair standard non-split 66 block contains 50 rows; each row has two (E) or four (M) or six (A) & (B) columns of clips that are electrically bonded. The 25-pair split 50 66 block is the industry standard for easy termination of voice cabling, and is a standard network termination by telephone companies—generally on commercial properties. Each row contains four (M) or six (B) clips, but the left-side clips are electrically isolated from the right-side clips. Smaller versions also exist with fewer rows for smaller-scale use, such as residential.
66 E blocks are available pre-assembled with an RJ-21 female connector that accepts a quick connection to a 25-pair cable with a male end. These connections are typically made between the block and the customer premises equipment (CPE).
Circuit pairs are connected to the block with a punch-down tool by terminating the tip wire on the leftmost slot of one row and ring wire on the leftmost slot of the row beneath the mating tip wire. Typically, a 25-pair cable coming from the phone company is punched down on the left side of a split-type block in pairs. The right hand side of the block is wired to the customer premises equipment with jumper wires. Bridging clips are used to connect the two center terminals, connecting the left-hand side of a split block with its right-hand side, thus completing the circuit. The clips form the point of interface between the subscriber and the provider. The bridging clips can be easily removed by either the subscriber or phone company personnel for trouble isolation, allowing the ability to split a circuit and determine in which direction trouble may exist. An orange insulating cover attached to a 66 block denotes its designation as a demarcation point by the local exchange carrier.
Modern 110 blocks (Originally designated as 88 blocks) have largely supplanted 66 blocks for new commercial installations at the end of the 20th century, as the capability for a circuit to carry digital data overlaid its ability to carry analog voice conversations. 110 block termination is almost always compliant with Category 5 (or higher) and therefore capable of supporting 100 MHz (or faster) signaling. Compared to 110 and higher-density wire terminating blocks, 66 blocks are physically large; and because of their maximum 16 MHz Category 3 signaling compatibility, they are ill-suited for high speed (faster than 10BASE-T) data circuits. However, special Category 5e Certified 66 blocks are available from manufacturers such as Siemon which meet all standards for Cat5e termination. [2]
Split 50 66 blocks are still used as network interface blocks in distribution frames to interconnect circuits with bridging clips, but are primarily limited to narrowband circuits such as POTS/DSL, DS0, or DS1 circuits.
In telephony, a main distribution frame is a signal distribution frame for connecting equipment to cables and subscriber carrier equipment.
Category 5 cable (Cat 5) is a twisted pair cable for computer networks. Since 2001, the variant commonly in use is the Category 5e specification (Cat 5e). The cable standard provides performance of up to 100 MHz and is suitable for most varieties of Ethernet over twisted pair up to 2.5GBASE-T but more commonly runs at 1000BASE-T speeds. Cat 5 is also used to carry other signals such as telephone and video.
Twisted pair cabling is a type of communications cable in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted balanced pair, a twisted pair reduces electromagnetic radiation from the pair and crosstalk between neighbouring pairs and improves rejection of external electromagnetic interference. It was invented by Alexander Graham Bell.
Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between parts of an electrical circuit, or between different electrical circuits, thereby joining them into a larger circuit. Most electrical connectors have a gender – i.e. the male component, called a plug, connects to the female component, or socket. The connection may be removable, require a tool for assembly and removal, or serve as a permanent electrical joint between two points. An adapter can be used to join dissimilar connectors.
A digital subscriber line access multiplexer is a network device, often located in telephone exchanges, that connects multiple customer digital subscriber line (DSL) interfaces to a high-speed digital communications channel using multiplexing techniques. Its cable internet (DOCSIS) counterpart is the cable modem termination system.
In telephony, the demarcation point is the point at which the public switched telephone network ends and connects with the customer's on-premises wiring. It is the dividing line which determines who is responsible for installation and maintenance of wiring and equipment—customer/subscriber, or telephone company/provider. The demarcation point varies between countries and has changed over time.
DMX512 is a standard for digital communication networks that are commonly used to control lighting and effects. It was originally intended as a standardized method for controlling stage lighting dimmers, which, prior to DMX512, had employed various incompatible proprietary protocols. It quickly became the primary method for linking controllers to dimmers and special effects devices such as fog machines and intelligent lights.
A registered jack (RJ) is a standardized telecommunication network interface for connecting voice and data equipment to a service provided by a local exchange carrier or long distance carrier. Registered interfaces were first defined in the Universal Service Ordering Code (USOC) system of the Bell System in the United States for complying with the registration program for customer-supplied telephone equipment mandated by the Federal Communications Commission (FCC) in the 1970s. They were subsequently codified in title 47 of the Code of Federal Regulations Part 68. Registered jack connections began to see use after their invention in 1973 by Bell Labs. The specification includes physical construction, wiring, and signal semantics. Accordingly, registered jacks are primarily named by the letters RJ, followed by two digits that express the type. Additional letter suffixes indicate minor variations. For example, RJ11, RJ14, and RJ25 are the most commonly used interfaces for telephone connections for one-, two-, and three-line service, respectively. Although these standards are legal definitions in the United States, some interfaces are used worldwide.
The 25-pair color code, originally known as even-count color code, is a color code used to identify individual conductors in twisted-pair wiring for telecommunications.
A lineman's handset is a special type of telephone used by technicians for installing and testing local loop telephone lines. It is also called a test set, butt set, or buttinski.
A 110 block is a type of punch-down block used to terminate runs of on-premises wiring in a structured cabling system. The designation 110 is also used to describe a type of insulation displacement contact (IDC) connector used to terminate twisted pair cables, which uses a punch-down tool similar to the type used for the older 66 block.
An insulation-displacement contact (IDC), also known as insulation-piercing contact (IPC), is an electrical connector designed to be connected to the conductor(s) of an insulated cable by a connection process which forces a selectively sharpened blade or blades through the insulation, bypassing the need to strip the conductors of insulation before connecting. When properly made, the connector blade cold-welds to the conductor, making a theoretically reliable gas-tight connection.
A punch-down block is a type of electrical connection often used in telephony. It is named because the solid copper wires are "punched down" into short open-ended slots which are a type of insulation-displacement connector. These slots, usually cut crosswise across an insulating plastic bar, contain two sharp metal blades which cut through the wire's insulation as it is punched down. These blades hold the wire in position and make the electrical contact with the wire as well.
BIX is part of a telephony cross-connect system created in the 1970s by Nortel Networks. As a system, it consists of various sizes of punch-down blocks, cable distribution accessories, and a punch-down tool to terminate wires at the punch-down block. The BIX cross-connect system as a whole is certified for Category-5e. The BIX cross-connect system is primarily composed of two parts: the mounts, and the connectors.
Parallel SCSI is the earliest of the interface implementations in the SCSI family. SPI is a parallel bus; there is one set of electrical connections stretching from one end of the SCSI bus to the other. A SCSI device attaches to the bus but does not interrupt it. Both ends of the bus must be terminated.
The 1A2 Key Telephone System is a business telephone system developed and distributed by the Western Electric Company for the Bell System.
A modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking, telecommunication equipment, and audio headsets.
A punch down tool, punchdown tool, IDC tool, or a Krone tool, is a small hand tool used by telecommunication and network technicians. It is used for inserting wire into insulation-displacement connectors on punch down blocks, patch panels, keystone modules, and surface mount boxes.
British telephone sockets were introduced in their current plug and socket form on 19 November 1981 by British Telecom to allow subscribers to connect their own telephones. The connectors are specified in British Standard BS 6312. Electrical characteristics of the telephone interface are specified by individual network operators, e.g. in British Telecom's SIN 351. Electrical characteristics required of British telephones used to be specified in BS 6305.
ANSI/TIA-568 is a technical standard for commercial building cabling for telecommunications products and services. The title of the standard is Commercial Building Telecommunications Cabling Standard and is published by the Telecommunications Industry Association (TIA), a body accredited by the American National Standards Institute (ANSI).