IEEE C37.1-1987 pdf free.IEEE Standard Definition,Specification, and Analysis of Systems Used for Supervisory Control, Data Acquisition, and Automatic Control.
IEEE C37.1 of terms contained in thisstandard，or in other American National Standards referred to in this standard，are not intended to em brace all legitimate meanings ofthe terms.They are applicable only to the subject treated in this American National Standard.Supervisory control and data acquisition systems may use computers.For standard definition of computer terms refer to ANSI x3 TR-1-1983[1].
Definitions in this standard may also be listedin ANSI/IEEE C37.100-1981 [18].
Definitions in ANSI/IEEE Std 100-1984 [20]are used whenever possible; however, sometimessuch definitions do not include the meaningassociated with the equipment governed bythis standard.
alarm condition. A predefined change in thecondition of equipment or the failure of equipment to respond correctly. Indication may beaudible or visual, or both.analog device. A device that operates withvariables represented by continuously mea-sured quantities such as voltages，resistances,rotations, and pressures.analog-to-digital (a/d) conversion. Productionof a digital output corresponding to the valueof an analog input quantity.
analog quantity. A continuous variable that istypically digitized and represented as a scalarvalue.
automatic. Pertaining to a process or devicethat，under specified conditions，functionswithout intervention by a human operator.
automatic circuitrecloser. A self-controlleddevice forautomaticallyinterrupting andreclosing an alternating current circuit，witha predetermined sequence of opening and re-closing followed by resetting, holdclosed，orlockout operation.
automatic line sectionalizer. A self containedcircuit-opening device that automatically opensthe main electrical circuit through it after sensing and responding to a predetermined numberof successive main current impulses equal to orgreater than a predetermined magnitude. Itopens while the main electrical circuit is deenergized. It may also have provision to bemanually operated to interrupt loads.automatic load throwover equipment (transferor switchover). An equipment that automatically transfers a load to another source of powerwhen the original source to which it has beenconnected fails, and that automatically restoresthe load to the original source under desiredconditions.IEEE C37.1 pdf download.