Characteristics of a Group

Key characteristics

A Group has some special characteristics as compared to the other object types:

A Group is a collection of related objects and descriptors
A Group cannot be represented by one unique descriptor.
Instead the Group typically contains a set of descriptors with underlying objects.
A Group will always be created in the Global area
A Group can be included in another Group
A Group can be exported to a file (.cgf) for import into another configuration
A set of name and PLC addressing substitution rules can be set up for a Group allowing you to reuse the Group members again and again.

Direct members and dependants

A Group is a self-contained object that can be pasted into the current configuration or imported into another configuration. Therefore, the Group contains not only the descriptors or objects you include, but also their dependants in the source configuration.

Member type

Characteristics

Direct member

A direct member is:

A descriptor you select on a diagram and add to the Group via the Add Selection button in the Group Manager dialog box.
An object added to the Group via the Browse button in the Group Manager dialog box

In order to include templates and unreferenced objects as direct members of the Group, you must use the Browse button. This may be relevant, for example, if you want to create Groups that only contain templates.

Likewise, you must use the Browse button in order to include a Group into another Group.

Dependant

When you include a direct member in a Group, its dependants in the source configuration are automatically included. The following elements are included when used by the direct members or dependants of the Group.

Templates
Areas and diagrams
Scaling objects, Protect objects and Connect objects
Alarm texts
Report formats
VBA code
Symbols
Base units
OPC configuration

An example

To illustrate the above with a simple example, let us imagine that we create a Group including the five descriptors shown in the figure below. We select the descriptors on the diagram and add them to the Group via the Add Selection button. The figure below shows a portion of the Pump Station diagram in the Demo configuration.

$images\Group_Members_and_Dependants_wmf.gif$

Limitations

When you create and use Groups, please be aware of the following limitations:

An IGSS object or descriptor can only be a direct member of one Group.
When you paste a Group, you can paste it either into the current diagram or into a new diagram. In the latter case, only the first diagram reference included in the Group will be pasted to a new diagram. The remaining diagram references will be pasted to existing diagrams, if applicable.
When you include a descriptor with a reference to an object, the descriptor is included as a direct member of the Group, but not the object itself. To include the object itself, click the Browse button in the Group Manager dialog box and drag the object name into the Group.
When you include an object to which VBA code has been attached, the object’s host module will be included as a dependant in the Group. But it is not possible to analyze what dependencies this host module may have in other VBA modules.