About Tags and the Project Database

Tags are a core component of any IWS project. Simply put, tags are variables used by IWS to receive and store data obtained from communication with plant floor devices, from the results of calculations and functions, and from user input. In turn, tags can be used to display information on screens (and Web pages), to manipulate screen objects, and to control runtime tasks.

But tags are more than simple variables. IWS includes a real-time database manager that provides a number of sophisticated functions such as time-stamping of any value change, checking tag values against runtime minimum and maximum values, comparing tag values to alarming limits, and so on. A IWS tag has both a value and various properties that can be accessed, some at development and others only at runtime.

All tags are organized into one of the following categories, which are represented by folders on the Global tab of the Project Explorer:

After creating a tag, you can use it anywhere within the project, and you can use the same tag for more than one object or attribute.