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DMX (lighting)
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 (such as a lighting console) to dimmers and special effects devices such as fog machines and intelligent lights. DMX512 has also expanded to uses in non-theatrical interior and architectural lighting, at scales ranging from strings of Christmas lights to electronic billboards and stadium or arena concerts. It can now be used to control almost anything, reflecting its popularity in all types of venues. DMX512 uses a unidirectional EIA-485 (RS-485) differential signaling at its physical layer, in conjunction with a variable-size, packet-based communication protocol. DMX512 does not include automatic error checking and correcti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Termination
In electronics, electrical termination is the practice of ending a transmission line with a device that matches the characteristic impedance of the line. Termination prevents signals from reflecting off the end of the transmission line. Reflections at the ends of unterminated transmission lines cause distortion which can produce ambiguous digital signal levels and mis-operation of digital systems. Reflections in analog signal systems cause such effects as video ghosting, or power loss in radio transmitter transmission lines. Transmission lines Signal termination often requires the installation of a terminator at the beginning and end of a wire or cable to prevent an RF signal from being reflected back from each end, causing interference, or power loss. The terminator is usually placed at the end of a transmission line or daisy chain bus (such as in SCSI), and is designed to match the AC impedance of the cable and hence minimize signal reflections, and power losses. Les ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twisted Pair
Twisted pair cabling is a type of wiring used for communications 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 neighboring pairs and improves rejection of external electromagnetic interference. It was invented by Alexander Graham Bell. For additional noise immunity, twisted-pair cabling may be shielded. Cable with shielding is known as shielded twisted pair (STP) and without as unshielded twisted pair (UTP). Explanation A twisted pair can be used as a balanced line, which as part of a balanced circuit can greatly reduce the effect of noise currents induced on the line by coupling of electric or magnetic fields. The idea is that the currents induced in each of the two wires are very nearly equal. The twisting ensures that the two wires are on av ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Characteristic Impedance
The characteristic impedance or surge impedance (usually written Z0) of a uniform transmission line is the ratio of the amplitudes of voltage and current of a single wave propagating along the line; that is, a wave travelling in one direction in the absence of reflections in the other direction. Alternatively, and equivalently, it can be defined as the input impedance of a transmission line when its length is infinite. Characteristic impedance is determined by the geometry and materials of the transmission line and, for a uniform line, is not dependent on its length. The SI unit of characteristic impedance is the ohm. The characteristic impedance of a lossless transmission line is purely real, with no reactive component. Energy supplied by a source at one end of such a line is transmitted through the line without being dissipated in the line itself. A transmission line of finite length (lossless or lossy) that is terminated at one end with an impedance equal to the charac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimmer
A dimmer is a device connected to a light fixture and used to lower the brightness of the lighting, light. By changing the voltage waveform applied to the lamp, it is possible to lower the luminous intensity, intensity of the light output. Although variable-voltage devices are used for various purposes, the term ''dimmer'' is generally reserved for those intended to lighting control system, control light output from resistive incandescent light, incandescent, halogen lamp, halogen, and (more recently) compact fluorescent lamps (CFLs) and light-emitting diodes (LED lamp, LEDs). More specialized equipment is needed to dim fluorescent lamp, fluorescent, mercury-vapor lamp, mercury-vapor, solid-state lighting, solid-state, and other arc lamp, arc lighting. Dimmers range in size from small units the size of domestic light switches to high-power units used in large theatrical or architectural lighting design, architectural lighting installations. Small domestic dimmers are generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Master/slave (technology)
Master/slave is a model of asymmetric communication or control where one device or process (the "master") controls one or more other devices or processes (the "slaves") and serves as their communication hub. In some systems, a master is selected from a group of eligible devices, with the other devices acting in the role of slaves. The ''master/slave'' terminology was first used in 1904. Since the early 21st century, the terms have become a subject of controversy from their association with slavery and some organizations have opted to replace them with alternative terms. Examples * In electronics, master/slave relationships are used to describe some of the following scenarios: ** In parallel ATA hard drive arrangements, the terms master and slave are used to describe drives on the same cable, but neither drive has control or priority over the other. ** A master clock that provides time signals used to synchronize one or more slave clocks as part of a clock network. ** In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daisy Chain (electrical Engineering)
In electrical and electronic engineering, a daisy chain is a wiring scheme in which multiple devices are wired together in sequence or in a ring, similar to a garland of daisy flowers. Daisy chains may be used for power, analog signals, digital data, or a combination thereof. The term ''daisy chain'' may refer either to large scale devices connected in series, such as a series of power strips plugged into each other to form a single long line of strips, or to the wiring patterns embedded inside of devices. Other examples of devices which can be used to form daisy chains are those based on Universal Serial Bus (USB), FireWire, Thunderbolt and Ethernet cables. Signal transmission For analog signals, connections usually consist of a simple electrical bus and, especially in the case of a chain of many devices, may require the use of one or more repeaters or amplifiers within the chain to counteract attenuation (the natural loss of energy in such a system). Digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Node (networking)
In telecommunications networks, a node (, ‘knot’) is either a redistribution point or a communication endpoint. The definition of a node depends on the network and protocol layer referred to. A physical network node is an electronic device that is attached to a network, and is capable of creating, receiving, or transmitting information over a communication channel. A passive distribution point such as a distribution frame or patch panel is consequently not a node. Computer networks In data communication, a physical network node may either be data communication equipment (DCE) such as a modem, hub, bridge or switch; or data terminal equipment (DTE) such as a digital telephone handset, a printer or a host computer. If the network in question is a local area network (LAN) or wide area network (WAN), every LAN or WAN node that participates on the data link layer must have a network address, typically one for each network interface controller it possesses. Examples a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multidrop Bus
A multidrop bus (MDB) is a computer bus in which all components are connected to the electrical circuit. A process of arbitration determines which device sends information at any point. The other devices listen for the data they are intended to receive. Multidrop buses have the advantage of simplicity and extensibility, but their differing electrical characteristics make them relatively unsuitable for high frequency or high bandwidth applications. In computing Since 2000, multidrop standards such as PCI and Parallel ATA are increasingly being replaced by point-to-point systems such as PCI Express and SATA. Modern SDRAM chips exemplify the problem of electrical impedance discontinuity. Fully Buffered DIMM is an alternative approach to connecting multiple DRAM modules to a memory controller. For vending machines MDB/ICP MDB/ICP (formerly known as MDB) is a multidrop bus computer networking protocol used within the vending machine industry, currently published by the Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American National Standards Institute
The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international standards so that American products can be used worldwide. ANSI accredits standards that are developed by representatives of other standards organizations, government agencies, consumer groups, companies, and others. These standards ensure that the characteristics and performance of products are consistent, that people use the same definitions and terms, and that products are tested the same way. ANSI also accredits organizations that carry out product or personnel certification in accordance with requirements defined in international standards. The organization's headquarters are in Washington, D.C. ANSI's operations office is located in New York City. The ANSI annual operati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
