In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a DTE such as a computer terminal or PC, and a DCE, such as a modem. The standard defines the electrical characteristics and timing of signals, the meaning of signals, and the physical size and pinout of connectors. The current version of the standard is TIA-232-F Interface Between Data Terminal Equipment and Data Circuit-Terminating Equipment Employing Serial Binary Data Interchange, issued in 1997. The RS-232 standard had been commonly used in computer serial ports and is still widely used in industrial communication devices.
Ethernet over twisted-pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. They are a subset of all Ethernet physical layers.
A data circuit-terminating equipment (DCE) is a device that sits between the data terminal equipment (DTE) and a data transmission circuit. It is also called data communication(s) equipment and data carrier equipment. Usually, the DTE device is the terminal, and the DCE is a modem.
Data terminal equipment (DTE) is an end instrument that converts user information into signals or reconverts received signals. It is also called data processing terminal equipment or tail circuit. A DTE device communicates with the data circuit-terminating equipment (DCE), such as a modem. The DTE/DCE classification was introduced by IBM.
On computers, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, terminals, various peripherals, and directly between computers.
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.
RS-422, also known as TIA/EIA-422, is a technical standard originated by the Electronic Industries Alliance, first issued in 1975, that specifies electrical characteristics of a digital signaling circuit. It was meant to be the foundation of a suite of standards that would replace the older RS-232C standard with standards that offered much higher speed, better immunity from noise, and longer cable lengths. RS-422 systems can transmit data at rates as high as 10 Mbit/s, or may be sent on cables as long as 1,200 meters (3,900 ft) at lower rates. It is closely related to RS-423, which uses the same signaling systems but on a different wiring arrangement.
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smallest connectors used on computer systems.
The Video Graphics Array (VGA) connector is a standard connector used for computer video output. Originating with the 1987 IBM PS/2 and its VGA graphics system, the 15-pin connector went on to become ubiquitous on PCs, as well as many monitors, projectors and high-definition television sets.
Null modem is a communication method to directly connect two DTEs using an RS-232 serial cable. The name stems from the historical use of RS-232 cables to connect two teleprinter devices or two modems in order to communicate with one another; null modem communication refers to using a crossed-over RS-232 cable to connect the teleprinters directly to one another without the modems. It is also used to serially connect a computer to a printer, since both are DTE, and is known as a Printer Cable.
A telephone jack and a telephone plug are electrical connectors for connecting a telephone set or other telecommunications apparatus to the telephone wiring inside a building, establishing a connection to a telephone network. The plug is inserted into its counterpart, the jack, which is commonly affixed to a wall or baseboard. The standards for telephone jacks and plugs vary from country to country, though the 6P2C style modular plug has become by far the most common type.
Power over Ethernet (PoE) describes any of several standards or ad hoc systems that pass electric power along with data on twisted-pair Ethernet cabling. This allows a single cable to provide both a data connection and enough electricity to power networked devices such as wireless access points (WAPs), IP cameras and VoIP phones.
In electronics, a pinout is a cross-reference between the contacts, or pins, of an electrical connector or electronic component, and their functions. "Pinout" now supersedes the term "basing diagram" which was the standard terminology used by the manufacturers of vacuum tubes and the RMA. The RMA started its standardization in 1934, collecting and correlating tube data for registration at what was to become the EIA. The EIA now has many sectors reporting to it and sets what is known as EIA standards where all registered pinouts and registered jacks can be found.
RS-485, also known as TIA-485(-A) or EIA-485, is a standard, originally introduced in 1983, defining the electrical characteristics of drivers and receivers for use in serial communications systems. Electrical signaling is balanced, and multipoint systems are supported. The standard is jointly published by the Telecommunications Industry Association and Electronic Industries Alliance (TIA/EIA). Digital communications networks implementing the standard can be used effectively over long distances and in electrically noisy environments. Multiple receivers may be connected to such a network in a linear, multidrop bus. These characteristics make RS-485 useful in industrial control systems and similar applications.
A medium-dependent interface (MDI) describes the interface in a computer network from a physical-layer implementation to the physical medium used to carry the transmission. Ethernet over twisted pair also defines a medium-dependent interface – crossover (MDI-X) interface. Auto–MDI-X ports on newer network interfaces detect if the connection would require a crossover and automatically choose the MDI or MDI-X configuration to complement the other end of the link.
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.
An Ethernet crossover cable is a crossover cable for Ethernet used to connect computing devices together directly. It is most often used to connect two devices of the same type, e.g. two computers or two switches to each other. By contrast, straight through patch cables are used to connect devices of different types, such as a computer to a network switch.
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.
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).
