Understand elements and attributes

Elements are the building blocks of PI AF (like Modules in PI MDB). Elements can represent anything. Some elements represent actual equipment or processes. Other elements are there only to create the context.

Elements that represent equipment or processes have associated data; this data is defined in attributes on the element. Attributes can hold simple values, representing fixed information, such as the diameter of a tank. Alternatively, attributes can get their values from a data reference. Data references can be a PI point, a constant value, a formula, a value from a relational database, and so on.

The following figure shows a tree of elements organizing various corporate assets. The organization makes it easy to find the asset you are interested in. You can drill down on each element to see the associated attributes, which hold the data. The attributes for an element called Chemical Tank 101 are shown here.

Data is stored in attributes associated with each element

Use the PI System Explorer to work with AF elements and attributes. PI AF also allows you to create and use element templates to easily create new elements of a common type. Element templates essentially define a set of base attributes and ports for all elements that use that template. Create the template once and you can create as many elements based on the template as needed. Element templates save time and help ensure consistency across all elements.

Note: When an element is based on a template, you cannot edit the aliases and properties on the corresponding PI Module. This restriction is to prevent modifications that are not consistent with the template.