Tag properties

Tag properties are metadata associated with each project tag in the database.

Most of the time, you may think of project tags as simple program variables that store values, because that is how you typically use them in your project. Each tag, however, is in fact a complex data structure that can be handled in different ways during project run time, depending on how the tag properties are configured.

In addition to handling standard metadata like array size, data type, description, and scope, the tag properties can be used to configure alarm conditions, get tag quality, convert between different units of measurement, access individual bits, retain values through project restarts, save historical data, and so on.

Many tag properties can be viewed and edited directly in the Project Tags datasheet. In fact, every column in the datasheet (including Name) is another tag property, and while the datasheet shows the most common properties by default, you can configure it to show other properties in additional columns.

You can also open the Tag Properties dialog box, which shows all of the properties of a selected tag:

• Right-click the tag in the Project Tags datasheet and choose Tag Properties on the shortcut menu.

• Select the Properties command on the Home tab of the ribbon, in the Tags group.

  

Finally, you can get and set many tag properties during project run time, just as you would get and set the values of the project tags themselves.