Technical Reference Manual - InduSoft

Tags and the Project Database
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Project Tags dialog: Click the Datasheet View icon in the Project Tags folder.
The Project Tags datasheet contains five columns (see the following sample dialog).
Project Tags dialog
Use this dialog to create, modify, or delete tags or tag properties. You can right-click on a tag property and use
standard Windows commands to cut (Ctrl+X), copy (Ctrl+C), or paste (Ctrl+V), any tag and its properties. You
can also undo (Ctrl+Z) the last modification to a field.
Tip: You can sort the data in the Project Tags sheet and/or insert/remove additional columns to/
from the sheet by right-clicking on it and choosing the applicable option from the shortcut menu.
EXTENDING THE PROJECT TAGS DATASHEET
The Project Tags worksheet can be extended up to 65,488 rows, if necessary.
The datasheet is normally limited to a maximum of 32,721 rows. (This is separate from the maximum size of
the project database as a whole, as well as the runtime limit that is set when you select a target platform for a
new project.)
To extend the worksheet, edit your project file (project_name.app) to include the following entry:
[Options]
EnableExtendedTagCount=1
Doing so, however, brings the following restrictions:
• Project tags in rows 32,722–65,488 of the worksheet cannot be used as array indices in expressions. That
is, in an expression like Abs(numArray[indexTag]), indexTag cannot be in that range of rows. (This
restriction does not apply to the VBScript interface.)
• In a Class worksheet, only the first 32 class members can have alarms. For all class members after the
first 32, alarms will not work.
Generally speaking, extending the Project Tags datasheet stretches the capabilities of IWS and should be done
only when it's absolutely necessary. It is better to design your project to conserve tags.
Classes Folder
The Classes folder contains all of the project classes and their respective members. Classes are compound
tags consisting of user-defined data-type structures or tag types (Integer, Real, Boolean, and String). Classes
allow for high-level encapsulation in the project database. A class-type tag provides a set of values for its
members.
To define a class you must define the members and their types. Class members are variables that hold values
for an object with particular characteristics. Thus, the defining a class can be very useful for projects with a
repeating group of variables.
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