Configuring an ArchestrA Group Object

Although the ArchestrA namespace is flat, ArchestrA groups provide an artificial grouping hierarchy. Items are added in the same way at both the ArchestrA data source and group levels. In both cases, the same ArchestrA attribute is referenced, the exception being the ArchestrA Item ID Prefix that is provided at the group level.

To add a group object to your ArchestrA data source hierarchy

1. Select the new data source object, right-click it, and then click Add ArchestrAGroup Object on the shortcut menu.

   • A new object is created in the hierarchy tree and is named New_ArchestrAGroup_000 by default (in "edit mode"). Rename it, if desired. You are allowed to add up to 100 new group objects.

     Note: Do not configure an ArchestrA group name to be identical with an item prefix. This name clash could cause unexpected behavior. Identical means the same in a case-insensitive manner. For more information, see Using Item Prefixes. Naming an ArchestrA group the same as an item (or the first part of an item name) also causes an ambiguity in OI Gateway namespace. In other words, do not name an ArchestrA group "Float" if a "Float.PV.Value" item exists in the Galaxy.

     The New_ArchestrAGroup_000 Parameters configuration view (right pane) is displayed.

2. Configure the new group object according to the following option definitions:

   • Device Group Name – Name of the topic that DDE or SuiteLink clients of OI Gateway connect to in order to access items at the ArchestrA group. Default value is the concatenation of the ArchestrA object’s name and the group object’s name (this cannot be edited).

   • ArchestrA Item ID Prefix – A string prefixed to item names added through this ArchestrA group. For instance, a prefix of "Blower_" would be added to an item such as "001.Temp1" to create an item request of "Blower_001.Temp1". Default value is blank.

   • Read Only – Check this box to make all items connected through the ArchestrA group read only. This qualification is in addition to any read-only condition that ArchestrA imposes. Unchecking this box only removes OI Gateway-imposed read-only qualifications. In other words, items inherently read-only in the data source remain so. Default value is unchecked.

     Important: Each group or topic must be uniquely named for the data source associated with it.