Tag Properties Database (Points.mdb)

VTS provides a graphic user interface with which you can add, configure, modify and delete tags while your application is running.  There is no need to open and modify the tag properties database directly. (See: Tag Browser)

Using the Tag Browser you can view all the tags stored in the tag properties database, filter them by type, and add, delete, and copy them. At the click of a button, you can view each tag's properties in a clearly organized tag properties folder. The Tag Browser also gives you access to drawing methods tailored specifically for each type of tag, allowing you to create effective operator interfaces.

The relationship between the tag properties database and the VTS environment is illustrated in the following diagram:

 

The individual properties of each tag are stored in the database. These properties can be viewed and modified in the VTS environment by means of the Tag Browser. Because VTS provides you with the tools you need to view, add, modify and delete tags and their properties using the Tag Browser, you need not be familiar with databases or with Microsoft Access.

If you are familiar with databases, there may be occasions there is an advantage to making offline changes to the tag properties database. For example, you might wish to do a search and replace to driver used by multiple I/O tags or to add multiple tags to the database by importing a delimited text file or spreadsheet.

With an understanding of how the tag properties database is used by VTS you can make offline modifications to its data to save time when working on larger applications.

Every new application is given its own copy of the tag properties database. This database contains the structure required to store the properties for all standard tag types, but contains no data until you begin to configure tags for your application. By default, the tag properties database is named Points.mdb; however, this name can be changed to meet your needs. To do so, please refer to Changing the Name of the Tag Properties Database (Points.mdb).

As indicated by the file name extension, Points.MDB is in the format of a Microsoft Access Database file (.mdb file).  VTS applications may use databases that are stored in any format provided that the ODBC drivers that are installed on your workstation support the format. VTS uses a file DSN to provide the parameters for the appropriate ODBC driver to the tag properties database.

Any program that can create and alter databases, and their tables, and records mau be used to manage your tags without running VTS or your application.

Each of the standard tag types available in VTS has a set of properties inherent to that tag type, and each tag of that type is uniquely identified and defined by the properties it is given. Below is a list of the database tables that make up the default VTS tag properties database, one for each of the standard tag types.

 

 

Each of these tables is composed of fields that correspond to the properties of each tag type.

The records in each table define each individual tag. The fields of each record make up the properties or parameters of the tag. Each field holds one unit of information, usually either a series of characters or a numeric value.

Tags are stored in the application database as follows:

•    Each table stores all tags of one tag type

•    Each record stores one individual tag

•    Each field stores one tag property for a specific tag

 Every time you create a tag or make changes to the properties of an existing tag, the database is updated with the new tag information. All of this happens while your application is running.

Topics in this section:

Offline Tag Properties Database (Points.mdb) Editing

About Custom Queries and Constraints in the Tag Properties Database

Tag Properties Database and Remote Applications

Tag Properties Database and Security

Interface to the Tag Properties Database