Connectors | RJ11, RJ45, BNC Connector

Connectors, RJ11, RJ45, BNC Connector

Connectors in networking

In computer network or networking connectors are an essential component. Connector in networking is used for termination of a segment of cabling or provides a point of entry for networking devices such as computers, hubs, and routers. They can be differentiate according to their physical appearance and mating properties, such as jacks and plugs (male connectors) or sockets and ports (female connectors).

Connectors attach components together. Several types of connectors are available, serving various purposes. For example, connectors are used to:

  1. Connect network interface cards, such as an Ethernet card, to a cable;
  2. Connect cable segments (e.g., thin coax to thin coax); and
  3. Terminate a segment.

In this last category, connectors actually connect the cable to a terminating resistor or an array of resistors and are consequently known as terminators. The type of Connectors used is usually a function of cable type.

Connectors are also classified on their genders, and they do indeed “mate”. You can your imagination about how a connector’s gender is derived, but a “plug” is usually lebel a clear specification of exactly which of a mating pair of connectors should be used in the particular application.

Types of connectors

Connectors are also frequently labeled by their type.

Three common types are

  1. DB (DataBase) type,
  2. Centronics, and
  3. DIN (Deutsche Industrie Norm)

DB (data bus) connector serves as an interface between a computer and a peripheral device such as a printer or external modem; they are distinguished as a rectangular row of “pins” (for male connectors) or “holes” (for female connectors). Several types of DB connectors exit and are distinguished by the number of pins they contain. Common types include DB-9 (a 9-pin serial or video interface), DB-15 (A 15-pin video interface), DB-25 (a 25-pin serial interface – RS-232 – or parallel printer interface), and DB-37 (a 37-pin serial interface based on RS-422).

DIN (Deutsche Industrie Norm, a German industrial standard) and Centronics connectors are similar to DB-type connectors except DIN connectors are circular instead of rectangular, and Centronics connectors contain “teeth” instead of pins. DIN connectors are typically used to connect a keyboard to computers.

Other connectors types include coax, v-type, fiber, video, SCSI, and modular.

Registered Jack (RJ)

A registered jack (RJ) is a standardized physical network interface — both jack construction  and wiring pattern — for connecting telecommunications or data equipment to a service provided by a local exchange carrier or long distance carrier. The standard designs for these connectors and their wiring are named RJ11, RJ14, RJ21, RJ48, etc. Many of these interface standards commonly used in North America, though some interfaces are used world-wide.

Registered Jack Connectors, RJ, Registered Jack Connector
Registered Jack Connectors

The physical connectors that registered jacks use are mainly of the modular connector and 50-pin miniature ribbon connector types. For example, RJ11 uses a 6 position 2 conductor (6P2C) modular plug and jack, while RJ21 uses a 50-pin miniature ribbon connector.

There is much confusion over these connection standards. The six-position plug and jack commonly used for telephone line connections may be used for RJ11, RJ14 or even R125, all of  which are actually names of interface standards that use this physical connector. The RJ11 standard dictates a 2-wire connection, while RJ14 uses a 4-wire configuration, and RJ25 uses all six wires.

The RJ abbreviations, though, only pertain to the wiring of the jack (hence the name registered jack); it is commonplace but not strictly correct to refer to an unwired plug connectors by any of these name.

The most familiar registered jack is probably the RJ11. This is a modular connector wired for one plain old telephone service line (using two wires out of six available positions). and is found in most homes and offices in most countries of the world for single-line telephones.

Registered Jack- 45 (RJ-45)

Ethernet cables are terminated with RJ45 connectors. Often termed an 8P8C connector, this means there are eight positions which are occupied by eight contacts and, it fits into a socket called a module.

RJ-45 connector, RJ45 connectors
RJ-45 connector

When viewed end-on, RJ45 connectors are oblong. Do not Confuse this connector with, the RJ11 connector. The RJ11 standard, also called 6P4C, is widely used to connect DSL routers to telephone lines. An RJ11 plug when viewed end-on is square-ish not oblong.

RJ45 is a keyed connector, meaning the connector can be inserted in only one way.

The above figure of the RJ45 connector wiring plan. There is no need to strip the eight cables bare before they are located inside the connector. The plug contacts have teeth that bite through the insulation in a technique called insulation displacement. The contacts must be punched down firmly in order to make reliable contact.

Registered Jack- 11 (RJ-11)

The six-position plug and jack commonly used for telephone line connections may be used for RJ11, RJ14 or even RJ25, all of which are actually names of interface standards that use this physical connector.

RJ11
RJ11 Connector

The RJ11 standard dictates a 2-wire connection, while RJ14 uses a 4-wire configuration, and RJ25 uses all six wires. The RJ abbreviations, though, only pertain to the wiring jack (hence the name “registered jack”); it is commonplace but not strictly correct to refer to an unwired plug connector by any of these names. 

BNC Connector

The BNC connector (Bayonet Neill-Concelman connector) is a common type of RF connector  used for the coaxial cable which connects to various types of radio, television, and other radio frequency electronic equipment.

The connector was named after its bayonet mount locking mechanism and inventors, Paul Neill and Carl Concelman. Neill worked at Bell Labs and also invented the N connector; Concelman worked at Amphenol and also invented the C connector.

BNC Connector
BNC Connector

The BNC connector is often called other names. Among, them are the Baby Neill-Concelmun conncetor, the Baby N connector, the British Naval connector, and the Bayonet Nut connector.  It is usually applied for frequencies below 3 Gilz and voltages below 500 Volts.

Three types of BNC connectors exist such as

  • BNC-T: Connect the network boards in the PC to the network.
  • BNC Terminator: A BNC terminator is a special connector that includes a resistor that carefully matched the characteristics of the cable system.
  • Barrel BNC connector: A BNC barrel connector connects to Thin net cables.
  • BNC cable connector: It attaches cable segment to the T-connectors.

Uses

Many types of electronic test equipment components are configured for the BNC connector. Aviation equipment also frequently employs the use of BNC connectors as well. A third application with amateur radio antenna connections, making it a popular option with ham radio operators.

Early in the development of consumer-based access to the Internet, the BNC connector was used with Ethernet networks. This application has mainly fallen out of favor since modern Ethernet network components tend to use a construction that does not include coaxial cables.

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