Setting Up Group Templates and Group Instances

This section explains how to set up a Group Template and a Group Instance. You can use the principles of the following procedure to construct more complex Group Template and Group Instance set-ups that are more suited to your specific requirements.

To set up a Group Template and Group Instance:

1. Ensure that you have carried out any necessary Preparation.
2. Add a Group Template.
3. Configure the Group Template (see Configure a Group Template).
4. Add items to the Group Template.

   You need to add database items that meet your requirements. Remember that these items do not actually represent ‘live’ data.

   For further information, see Add Items to a Group Template and, if applicable, see Add an Abstract Item to a Group Template.

5. Configure the items in the Group Template (see Configure the Items in a Group Template).
6. Use the Property Overrides feature to define which properties can be overridden locally by the Group Instances (see Define which Property Values Derive from a Group Template).
7. Set the required security for the Group Template and its content (the same security settings will apply to all Instances that reference the Template, unless you set security to be overridden locally by the Group Instances).
8. Add a Group Instance.

   Versions of the items that you have added and configured in the Group Template will be added automatically to the Group Instance. Each item in the Group Instance will have the same configuration as the corresponding item in the Group Template.

   The database items in the Group Instance will be ‘live’ and will represent actual programs, or plant, and so on. (The exception to this is any Abstract Items that you will need to convert into specific types of point or outstation in order for them to become ‘live’.)

9. Configure the Group Instance (see Configure a Group Instance).
10. For each item within the Group Instance, configure those properties that can be overridden locally in the Group Instance (see Configure the Properties that are Unique to the Items in a Group Instance).
11. If applicable, convert into specific point or outstation types, any Abstract Items that are to be used in the Group Instance (see Convert an Abstract Item into a ‘Real’ Point or Outstation).

    You will need to configure any type-specific properties in the converted item.

    Where an Abstract item remains unconverted, it will effectively be ignored by ClearSCADA.

12. Repeat steps 8 onwards for any further Group Instances that are to reference the same Group Template.

If required, you can make further configuration changes to a Group Template and items in that Group Template after Group Instances have been associated with that Group Template. ClearSCADA will propagate any such changes to each of the Group Instances that reference that Group Template. The time taken to do this, if noticeable, should only be seconds providing that fewer than 100 Group Instances reference the Group Template. With a larger number of Group Instances, access to the database might be prevented for a more noticeable amount of time (see Activities that are Restricted when Configuration or Structure Changes are Pending).