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Data Link
A data link is a means of telecommunications link, connecting one location to another for the purpose of transmitting and receiving digital information (data communication). It can also refer to a set of electronics assemblies, consisting of a transmitter and a receiver (two pieces of data terminal equipment) and the interconnecting data telecommunication circuit. These are governed by a link protocol enabling digital data to be transferred from a data source to a data sink. Types There are at least three types of basic data-link configurations that can be conceived of and used: * Simplex communications, most commonly meaning all communications in one direction only. * Half-duplex communications, meaning communications in both directions, but not both ways simultaneously. * Duplex (telecommunications), Duplex communications, communications in both directions simultaneously. Aviation In civil aviation, a data-link system (known as Controller Pilot Data Link Communications) is use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telecommunications Link
In a telecommunications network, a link is a communication channel that connects two or more devices for the purpose of data transmission. The link may be a dedicated physical link or a virtual circuit that uses one or more physical links or shares a physical link with other telecommunications links. A telecommunications link is generally based on one of several types of information transmission paths such as those provided by communication satellites, terrestrial radio communications infrastructure and computer networks to connect two or more points. The term ''link'' is widely used in computer networking to refer to the communications facilities that connect nodes of a network. Sometimes the communications facilities that provide the communication channel that constitutes a link are also included in the definition of ''link''. Types Point-to-point A point-to-point link is a dedicated link that connects exactly two communication facilities (e.g., two nodes of a networ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nav Canada
Nav Canada (styled as NAV CANADA) is a privately run, non-profit corporation that owns and operates Canada's civil air navigation system (ANS). It was established by statute in accordance with the ''Civil Air Navigation Services Commercialization Act'' (ANS Act). The company employs approximately 1,900 air traffic controllers (ATCs), 650 flight service specialists (FSSs) and 700 technologists. It has been responsible for the safe, orderly and expeditious flow of air traffic in Canadian airspace since November 1, 1996 when the government transferred the ANS from Transport Canada to Nav Canada. As part of the transfer, or privatization, Nav Canada paid the government CA$1.5 billion. Nav Canada manages 12 million aircraft movements a year for 40,000 customers in over 18 million square kilometres, making it the world's second-largest air navigation service provider (ANSP) by traffic volume. Nav Canada, which operates independently of any government funding, is headquartered in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timex Datalink
Timex Datalink or Timex Data Link is a line of early smartwatches manufactured by Timex and is considered a wristwatch computer. It is the first watch capable of downloading information wirelessly from a computer. As the name implies, datalink watches are capable of data transfer through linking with a computer. The Datalink line was introduced in 1994 and it was co-developed with Microsoft as a wearable alternative to mainstream PDAs with additional attributes such as water resistance, that PDAs lacked, and easy programmability. The watch was demonstrated by Bill Gates on 21 June 1994 in a presentation where he downloaded information from a computer monitor using bars of light and then showed to the audience the downloaded appointments and other data. The early models included models 50, 70, 150 and model 150s (small size). The model numbers indicated the approximate number of phone numbers that could be stored in the watch memory. These early models were, at the time of their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal (telecommunication)
In the context of telecommunications, a terminal is a device which ends a telecommunications link and is the point at which a signal enters or leaves a network. Examples of terminal equipment include telephones, fax machines, computer terminals, printers and workstations. An end instrument is a piece of equipment connected to the wires at the end of a telecommunications link. In telephony, this is usually a telephone connected to a local loop. End instruments that relate to data terminal equipment include printers, computers, barcode readers, automated teller machines (ATMs) and the console ports of router (computing), routers. See also * Communication endpoint * Data terminal equipment * End system * Host (network) * Node (networking) * Terminal equipment References External links Directive 1999/5/EC of the European Parliament and of the Council of 9 March 1999 on radio equipment and telecommunications terminal equipment and the mutual recognition of their conform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tactical Data Link
A tactical data link (TDL) uses a data link standard in order to provide communication via radio waves or cable. NATO nations use a variety of TDL standards. All military C3 systems use standardized TDL to transmit, relay and receive tactical data. Multi-TDL network (MTN) refers to the network of similar and dissimilar TDLs integrated through gateways, translators, and correlators to bring the common tactical picture and/or common operational picture together. Change of terminology The term ''tactical digital information link (TADIL)'' was made obsolete (per DISA guidance) and is now more commonly seen as ''tactical data link (TDL)''. Tactical data link character TDLs are characterized by their standard message and transmission formats. This is usually written as <Message Format>/<Transmission Format>. TDL standards in NATO In NATO, tactical data link standards are being developed by the ''Data Link Working Group (DLWG)'' of the ''Information Systems S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Probe
Uncrewed spacecraft or robotic spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input, such as remote control, or remote guidance. They may also be autonomous, in which they have a pre-programmed list of operations that will be executed unless otherwise instructed. A robotic spacecraft for scientific measurements is often called a space probe or space observatory. Many space missions are more suited to telerobotic rather than crewed operation, due to lower cost and risk factors. In addition, some planetary destinations such as Venus or the vicinity of Jupiter are too hostile for human survival, given current technology. Outer planets such as Saturn, Uranus, and Neptune are too distant to reach with current crewed spaceflight technology, so telerobotic probes are the only way to explore them. Telerobotics also allows exploration of regions that are vulnerable to contamination by Earth micro-organisms sinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Deep Space Network
The NASA Deep Space Network (DSN) is a worldwide Telecommunications network, network of spacecraft communication ground segment facilities, located in the United States (California), Spain (Madrid), and Australia (Canberra), that supports NASA's interplanetary spaceflight, interplanetary spacecraft missions. It also performs radio astronomy, radio and radar astronomy observations for the exploration of the Solar System and the universe, and supports selected Earth-orbiting missions. DSN is part of the NASA Jet Propulsion Laboratory (JPL). General information DSN currently consists of three deep-space communications facilities located such that a distant spacecraft is always in view of at least one station. They are: * the Goldstone Deep Space Communications Complex () about north of Barstow, California, Barstow, California. For details of Goldstone's contribution to the early days of space probe tracking, see Project Space Track (1957-1961), Project Space Track; * the Mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ACARS
In aviation, ACARS (; an acronym for Aircraft Communications Addressing and Reporting System) is a digital data communication system for transmission of short messages between aircraft and ground stations via airband radio or satellite. The protocol was designed by ARINC and deployed in 1978, using the Telex format. More ACARS radio stations were added subsequently by SITA. History of ACARS Prior to the introduction of datalink in aviation, all communication between the aircraft and ground personnel was performed by the flight crew using voice communication, using either VHF or HF voice radios. In many cases, the voice-relayed information involved dedicated radio operators and digital messages sent to an airline teletype system or successor systems. Further, the hourly rates for flight and cabin crew salaries depended on whether the aircraft was airborne or not, and if on the ground whether it was at the gate or not. The flight crews reported these times by voice to geographi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telemetry
Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', 'far off', and ''metron'', 'measure'. Systems that need external instructions and data to operate require the counterpart of telemetry: telecommand. Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio, ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a telephone or computer network, optical link or other wired communications like power line carriers. Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data. A ''telemeter'' is a physical device used in telemetry. It consists of a sensor, a transmission path, and a display, recording, or control device. Electronic devices are widely u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control System
A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial control systems which are used for controlling processes or machines. The control systems are designed via control engineering process. For continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable (PV) being controlled with the desired value or setpoint (SP), and applies the difference as a control signal to bring the process variable output of the plant to the same value as the setpoint. For sequential and combinational logic, software logic, such as in a programmable logic controller, is used. Open-loop and closed-loop control Feedback control systems Logic control Logic control systems for indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half-duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow for simultaneous communication in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment of equipment in the field. There are two types of duplex communication systems: full-duplex (FDX) and half-duplex (HDX). In a full-duplex system, both parties can communicate with each other simultaneously. An example of a full-duplex device is plain old telephone service; the parties at both ends of a call can speak and be heard by the other party simultaneously. The earphone reproduces the speech of the remote party as the microphone transmits the speech of the local party. There is a two-way communication channel between them, or more strictly speaking, there are two communication channel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
