Close

Create a link to this page

Copy and paste this link tag into your Web page or blog:

<a href="http://www.encyclopedia.com/doc/1E1-signalin.html" title="Facts and informations about signaling">signaling</a>

signaling

signaling transmission of information by visible, audible, or other detectable means. Since prehistoric times humans have sought and employed ever more effective means of communicating over distance. Signal fires on mountain tops announced awaited events. In Africa a sophisticated system of drum beating was used, where the tone and the rhythm determined the meaning. Some Native Americans used smoke signals to send messages. In the American Revolution the colonists used combinations of three articles for signaling—a barrel, a basket, and a flag placed in different positions atop a post. In the early days of railroading, men were posted at places where accidents might occur, e.g., at stations and tunnels, and signaled to the engineer by flag or lamp. Modern railroad signaling depends upon electrically operated indicators which constitute a semaphore system. The position of a movable arm swinging from a pivot indicates whether the train can go forward or must wait and whether it should go rapidly or slowly. Most electric trains, including subways, are fitted with automatic devices that turn the power off and the brakes on if the engineer ignores a stop signal. Railroads also use light signals to duplicate the positions of a semaphore arm. In marine signaling, flags have been used for hundreds of years. The International Code of Signals was compiled by the British government in 1857 and, by international agreement, was amended to the present system in 1901. It utilizes a number of flags of various colors and forms; each flag represents a certain letter or number, and the flags are hoisted to convey a message to another vessel or to the shore. Blinker lights are much used by naval units. At night flash lamps using Morse code or another code may be used for signaling. Fog signals are commonly used by vessels and lighthouses when visibility conditions make visual warnings ineffective. While radio and telephone apparatus have largely superseded many of these devices, they are still used as backup systems of communication. In modern times aerial and marine craft are commonly given directional data through radio beacon signals or from orbiting satellites to get a fix on their position. In the home, signaling takes on numerous forms from the simple doorbell to intercom systems. Some intercom systems use dedicated wires, and others the power lines by means of carrier-current signaling. Various remote-control devices use signaling: infrared signals, sent in coded pulses, are used to control the function of audio and video entertainment devices. See information theory ; code .

Related newspaper, magazine, and trade journal articles from HighBeam Research

(Including press releases, facts, information, and biographies)

	Intercom firm guarantees service till year 2000. (Jordan Intercom Systems) (Brief Article) Magazine article from: Real Estate Weekly; 11/13/1991; 179 words ; ...most residential or commercial intercom systems are given a one-year warranty at best, Jordan Intercom Systems of New York, is now guaranteeing...Jordan Lubitz, president of Jordan Intercom Systems, the need for more sophisticated... Read more
	Flags 'intimidating' claim. Newspaper article from: Lurgan Mail (Portadown, Northern Ireland); 7/3/2008; 376 words ; A NUMBER of people have said unionist flags put up around the town is intimidating...community. Over the weekend Union and Ulster flags were put up on flag poles and lamp posts...MAIL' to say they were angered over the flags throughout the town. One Lurgan man said... Read more
	Mayor lambasts 'provocative' flags. Newspaper article from: Tyrone Times (Dungannon, Northern Ireland); 7/10/2007; 473 words ; ...has broken out over the flying of Union flags in Dungannon's Market Square. Dungannon...Monteith has criticised the proliferation of flags, claiming that it is 'an attempt to make...Larry McLarnon, the Mayor warned that the flags 'were extremely provocative at this time... Read more
	Florence booster makes sure flags fly.(General News) Newspaper article from: The Register-Guard (Eugene, OR); 2/16/2005; 280 words ; ...program, responsible for the myriad U.S. flags found flapping in the coastal breeze on...contract with Iholts to install and remove the flags was up, the program was in jeopardy of...Chamber of Commerce, boosting Florence's flags from 92 to a whopping 420. That's not all... Read more
	Majority of Catholics and Protestants surveyed say: We don't want flags. Newspaper article from: Derry Journal (Derry, Northern Ireland); 3/11/2008; 365 words ; ...Derry don't want republican and loyalist flags flown in the city, new research reveals...Columb's Park House, says the issue of flags has generated much debate within and between...added: When we discussed the results of our flags research with community development workers... Read more
	Derry people speak out: We don't want flags. Newspaper article from: Derry Journal (Derry, Northern Ireland); 3/10/2008; 401 words ; ...Derry don't want republican and loyalist flags flown in the city, new research reveals...Columb's Park House, says the issue of flags has generated much debate within and between...added: When we discussed the results of our flags research with community development workers... Read more
	USA: NORTHROP GRUMMAN AWARDED CONTRACT FOR INTERCOM SYSTEMS. Newspaper article from: IPR Strategic Business Information Database; 8/7/2005; 68 words ; Northrop Grumman of Linthicum, Md., was awarded Aug. 1, 2005, a $37,502,620 firm-fixed price contract for vehicular intercom systems. Work will be performed at Northrop Grumman's Reston, Va., facilities and will be completed by Jan. 31, 2007... Read more
	USA: NORTHROP GRUMMAN AWARDRD CONTRACT FOR VEHICULAR INTERCOM SYSTEMS. Newspaper article from: IPR Strategic Business Information Database; 3/10/2005; 94 words ; ...awarded on March 4, 2005, a delivery order amount of $0 as part of a $70,000,000 firm-fixed-price contract for Vehicular Intercom Systems, 9,500 Master Control Station/Light, and 19,000 Full Function Crew Station/Lights. Work will be performed in Reston, Va... Read more
	Rate-payers intimidated by flags claims Digney. Newspaper article from: Ballymena Times (Ballymena, Northern Ireland); 7/29/2008; 303 words ; ...intimidated' by the flying of unionist flags at the Council's amenity site. The Sinn Fein councillor called on NIE to remove the flags from lampposts at the Council yard, off...and intimidated by the presence of these flags, in what is meant to be shared space, I... Read more
	Loyalists remove Republican flags from town centre. Newspaper article from: Mid Ulster Mail (Portadown, Northern Ireland); 5/7/2008; 324 words ; ...to have removed a number of Republican flags erected Magherafelt town centre, the MAIL...at the weekend over the removal of seven flags erected to commemorate the Easter Rising...It's the second time in a week that the flags, including an Irish tricolour and a starry... Read more

For more facts and information, see all related premium articles

Related entries from encyclopedias, dictionaries, and thesauruses

	Signaling and Signal Transduction Book article from: Biology Signaling and Signal Transduction All cells are able to sense and...transmitted through the body by the action of extracellular signaling molecules called neurotransmitters . Insulin, a hormone...hormones are two important examples of extracellular signaling molecules released by one cell to influence ... Read more
	spread spectrum signaling Book article from: A Dictionary of Computing spread spectrum signaling A form of modulation in which the frequency of the carrier for the...predetermined possible frequencies. This has several advantages over signaling using a fixed allocation of frequencies. Its use may allow a number... Read more
	baseband signaling Book article from: A Dictionary of Computing baseband signaling See baseband networking . Read more
	d.c. signaling Book article from: A Dictionary of Computing d.c. signaling See baseband networking . Read more
	telegraph Book article from: The Columbia Encyclopedia, Sixth Edition ...communication date back thousands of years (see signaling ). As electricity came into greater use...practical and experimental methods of signaling were tried. A method that came into general...clicks, is a swift and reliable method of signaling. The first permanently successful telegraphic... Read more

See all related entries