Tag Template Modules

Tag template modules contain the code that defines each tag type available to your application. Tag template modules define not only what data types are available, but also how those data types can be displayed, their logic, their control actions, their alarm behavior, and all other characteristics native to tags of that type.

The modules for a tag template are typically stored in three separate files. This makes it easier to maintain and update the tag's code and makes it easier to find the various parts of the complete tag template. In the following example "Cnf" (appended to the tag name) indicates "Configuration modules" and "Cmn" indicates "Common modules"

You must declare all of the custom tags that you add to an application in the [POINTS] class of the application’s AppRoot.SRC file. VTScada will do this automatically when you run the Create New Type command on a Context tag.

You must also declare the configuration module and common module in the [PLUGINS ] class of AppRoot.SRC. You will then edit the source code for the tag itself so that it can find and use those submodules when needed.

Note that neither of these submodule are necessary for a context-derived type and VTScada will not create either of the submodules for you when creating a new type from a Context tag. If you choose to have a custom configuration panel and common module, you must write that code yourself. Examples are provided later in this chapter.

New types derived from Context tags do not count against your VTScada license limit until you add custom code to them, after which every instance of that type will be counted.