Limitations and Restrictions

You can include any item in a Group Template, except the following:

• Another Group Template
• An Operator Document Store
• A Data Table
• A User
• A Script Library
• A Function Block Library
• A Structured Text Library.

If need be, you can Optionally Add Items Directly into a Group Instance. However, you need to be aware of the following:

• Any item that you add locally to a Group Instance will be automatically deleted if the Instance’s configuration is later changed to reference a different Group Template.
• You can add any item other than a Group Template locally to a Group Instance.
• If you add a Group Instance to another Group Instance, each of those Instances has to reference a different Group Template (a Group Instance cannot reference the Group Template of any Group Instance in its parent chain).

• The impact of the Exclude From Exclusive Control setting on a Group, Group Template, or Group Instance when adding, copying, or importing database items into that Group, Group Template, or Group Instance: see Copying Database Items when using the Exclusive Control Feature.

If need be, you can optionally nest a Group Instance inside a Group Template. However, be aware of the following:

• The Property Overrides settings of the outer Group Template (the one within which the Group Instance is nested) will not change when the Group Instance is moved into (or out of) that Group Template. Instead, for those Property Overrides settings that are to differ from the default in the Group Instance that is nested within that Group Template, you have to specify the required Property Overrides settings. You do this using the Property Overrides feature on the outer Group Template within which that Group Instance is nested.

  Any Property Overrides settings that you adjust in the outer Group Template will then impact any instances of that Group Template, including the Group Instance that is nested within the instances of that Group Template.

Geo SCADA Expert supports Incremental Import. If you use the Import menu option to import configuration from one Geo SCADA Expert database to another, be aware of the following:

• The configuration of a Group Instance that is imported successfully into a database is compared to that of its Group Template (Geo SCADA Expert automatically runs the Repair Instance method on each imported Group Instance). Geo SCADA Expert checks whether any changes have been made to the Group Template between the Instance being exported and then imported. It then applies any changes that are found to the Group Instance.
• If a Group Instance is imported into a database and that import would result in a situation in which the Group Instance would be invalid:
  • The imported Group Instance will be converted into a ‘normal’ Group
  • Any database items in the Instance that are not supported by normal Groups (such as Abstract Items) will be deleted.

    Situations in which a Group Instance would be invalid include:

  • A Group Instance being imported into a database in which the Instance’s referenced Group Template does not exist
  • A Group Instance being imported into its own Group Template
  • A Group Instance being imported into another Group Instance, which itself references the same Group Template as the Group Instance that is being imported.

Should you make changes to a Group Template which has Group Instances that reference it, Geo SCADA Expert will automatically propagate the changes to each of those Group Instances. With Group Templates that are referenced by fewer than 100 Group Instances, the time taken to propagate such changes should take only seconds, if noticeable at all. With large or complicated Group Template and Group Instance set-ups, there may be a noticeable period for which access to the database is prevented while the server propagates those changes. During this time Geo SCADA Expert will block attempts to make certain changes locally to a Group Instance while the server is in the process of propagating any Group Template configuration changes to that Group Instance (see Activities that are Restricted when Configuration or Structure Changes are Pending). For a summary of the type of changes that Geo SCADA Expert blocks until it has completed propagating Group Template changes to a Group Instance, see Configuration Changes and Structure Changes.