Class tags are compound tags that permit a high-degree of encapsulation within the Tags database. Where basic tags receive a single value, classes are designed to receive multiple values.
You can create a class-type tag by grouping basic or array tags, which then become the class members. The maximum number of members for any class depends on the product specification.
You specify class-type tags in one of two formats:
- For a simple class tag the syntax is TagName.ClassMemberName. (Where the period is used as a separator.)
For example, if you wanted to monitor several different conditions (such as temperature, level and pressure) in a tank, you might create a class tag as follows:
- For creating a complex class tag (using an array tag) the syntax is ArrayTagName[ArrayIndex].ClassMemberName. (Where again, the period is used as a separator.)
If you wanted to monitor the temperature, level, and pressure conditions in multiple tanks, you might create a class tag as follows:
Where tk is an array index, representing the tank number.