Class Tags; How to Use Them; Deleting Class Members; Member Properties
Class structures in InduSoft web Studio SCADA software are user-defined tag types describing a generic object by its attributes. These user-defined attributes are called “members,” which describe various characteristics of the generic object. Tags created using a Class type can also be arrays just as with any other tag type.
An example of using this functionality would be when creating a recipe for a cake. Refer to the article, “Save Recipes as .XML Files in InduSoft Web Studio” for more information about the example in the following discussion.
This project uses Class tags to hold the unique member values for each cake recipe. Each Class tag has members in the Class structure that are generic to all cakes, and each class tag that is defined describes the type of cake that is to be created (Figure 1).
Figure 1: Class Structures can be viewed in the Project Explorer Tree or in the Datasheet View.
The example in the article uses 2 different Class tags of type cCake, one called “ChocoCake” and one called “VanillaCake”, each class tag having the same members, but containing values unique to that particular cake recipe (Figure 2).
Figure 2: All project tags can be viewed in the Project Explorer Tree or in the Datasheet View.
When a tag or Class member needs to be deleted, right-clicking on it will give the ability to delete the line from the tag database or the Class Structure. The tag/member list cannot be sorted or “Delete Line” will be greyed out – Choose “Disable Sort” first, if it is not already greyed out (Figure 3).
Figure 3: Tag and Class Member Right-Click Menu Options
Class tag members also have properties (Figure 4). A complete list of Tag Properties is located in the Help Manual (TechRef.chm) in the section: Contents >> Tags and the Project Database >> Setting Tag Properties >> List of Tag Properties. Member properties can be accessed during runtime by using the “->” operator (example: ChocoCake.OvenTemp->HiHiLimit).
Figure 4: Class Tag Member Properties Dialog
More information on Class Structures and Class Tags can be found in the help manual (TechRef.chm) in: Contents >> Tags and the Project Database >> Creating Database Tags >> Creating Classes and a video showing how to create and use classes in InduSoft Web Studio SCADA software is located on the InduSoft Training page.