3 Terms, definitions and abbreviated terms

3.1 Terms and definitions

For the purposes of this document, the terms and definitions given in OPC 10000-1, OPC 10000-3, and OPC 10000-4 and the following apply.

3.1.1 DataItem

link to arbitrary, live automation data, that is, data that represents currently valid information

3.1.2 AnalogItem

DataItem that represents continuously-variable physical quantities (e.g., length, temperature), in contrast to the digital representation of data in discrete items

3.1.3 DiscreteItem

DataItem that represents data that can take on only a certain number of possible values (e.g., OPENING, OPEN, CLOSING, CLOSED)

3.1.4 ArrayItem

DataItem that represents continuously-variable physical quantities and where each individual data point consists of multiple values represented by an array (e.g., the spectral response of a digital filter)

3.1.5 EngineeringUnits

units of measurement for AnalogItems that represent continuously-variable physical quantities (e.g., length, mass, time, temperature)

3.2 Abbreviated terms