Local Area Lingo: A Turn-of-the-Century Controls Glossary

02/01/2001


Control network : A collection of DDC microcontrollers distributed throughout a facility that use a control protocol and one or more network media to communicate.

Control protocol : An electronic language spoken between microcomputer-based DDC controllers to pass values and commands.

Direct-digital control (DDC): An automated control scheme using microcomputers connected to electronic sensors and actuators.

Distributed control : Automated control using microcomputer-based controllers distributed on a control network throughout a facility. Each microcontroller in a distributed system has local "intelligence" or logic capability and also communicates via a control protocol to other microcontrollers on a control network over one or more network media.

Gateway : A hardware or software device that translates from one control protocol to another.

Hierarchical control network : A method of building control networks where parent controllers manage small subnetworks with fixed numbers of controllers under a given parent device.

Media converter : A device used to move from one network media to another.

Microcontroller : A microcomputer with local logic capability as well as sensory input and actuator outputs used in a distributed control network .

Network media : The physical method of transmission of a control protocol . Examples include radio frequency, power-line carrier, infrared light and various wiring schemes such as Ethernet, twisted-pair and serial connections.

Parent controller : A logic device used in hierarchical control networks to manage a fixed number of smaller devices. Typical hierarchal implementations use this controller also as a gateway or media converter .

Peer-control network : A control network in which any device can communicate to any other device without the need to pass through a parent controller or gateway .

Plug-in : A small, device-specific software application or wizard provided by a manufacturer intended to add value to the product.

TCP/IP : The acronym for transmission-control protocol/Internet protocol, the common underlying protocol spoken by all devices and applications on the Internet.

Return to "Keeping Up with the Protocols .





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