Attribute value updates

An attribute with a PI point data reference can write a value to a PI point. In the PI Point Data Reference configuration window, the Read only check box determines whether the attribute can write data to the referenced PI point. By default, the check box is selected (Read only = True), meaning that the PI AF attribute cannot change the value of the PI point.

In rare cases, you might want to write the attribute value back to the point value. For example, if the attribute value is the result of a calculation or analysis, you can update the PI point with the result of that analysis. In this case, you would clear the Read only check box to allow the attribute to write its value to the point.

Note: Applications that use the AF SDK UpdateValue method, such as the PI Analysis Service, can write data to the PI point regardless of whether the Read only check box is selected or not.