Structure of the Global Database

The Global System Database (DB) contains Teams, DBs, Roles, Locations and Stamps. The illustration shows the structure of the Global System DB.

GSTAT Element (GSTAT)

Only one /*GS element can exist in the DB and it is inherited from the STAT element in the Standard System DB.

Attributes:

GTMWL Element

The Global Team World element GTMWL is named /*GT. Only one /*GT element can exist in the DB. It is the same as the TMWL element, except that:

• It does not own a User list element USLI.

• The DB element does not own an MDB list element MDBL.

• The DB element owns a single DBLOC element.

Attributes:

TEAM Element

Attributes:

Database List Element (DBLI)

Attributes:

DB Element

The DB element owns the list element DBLOC which holds four additional attributes, refer to DBLOC element. These attributes are attached to the DBLOC element to facilitate separate claiming of both this element and the owning DB element. This scheme reduces the contention between the AVEVA Administration and the Global daemon.

Attributes:

DBLOC Element

Attributes:

Global Role World (GROLW)

The Global Role World element stores the ROLE elements in a Global Project.

Attributes:

Role Element (ROLE)

Attributes:

Perop Element (PEROP)

Attributes:

GLOCWL Element

The Global Location World element GLOCWL specifies information about Locations, Groups and Communications (Links). It is named /*GL and only one /*GL element can exist in the DB. The GLOCWL element consists of the three list elements GRPLI for groups, LOCLI for Locations and LNKLI for links. It has the following attributes:

Attributes:

GRPLI Element

The GRPLI element contains a list of Group elements GRP. A Group is a fully connected local network of Locations which conceptually form a single node in the Plant Design Global-tree structure of Locations.

Attributes:

GRP Element

The characteristics of each group are defined by a GRP element which has the following attributes:

Attributes:

Membership of a group is indicated by the attribute GRPRF in each Location element LOC, as described below. The Location elements LOC are themselves listed in the LOCLI element.

LOCLI Element

The LOCLI element contains a list of all Location elements LOC, including offline Locations and those which belong to Groups.

Attributes:

LOC Element

The characteristics of each Location are defined by a LOC element which has a set of attributes and a secondary list element DBALL. The DBALL element is a complete list of all DBs allocated to the Location. It is implemented as a Dabacon secondary list of DB reference numbers which refer to DB elements under the DBLI list element of Team elements.

Locations which belong to a Group have an attribute GRPRF holding the reference number of the Group. If this attribute is null then the Location does not belong to a group. LOC elements also possess a LOCRF attribute which points to the parent of the Location. This attribute is used to determine paths between Locations in the proposed tree structure for connecting Locations.

In a future implementation, based on a more general graph structure, the LOCRF attribute might either be dropped or used for another purpose. A Location is only recognized as fully initialized when the logical attribute LINIT is true. Other attributes of a Location are described in the following table.

The LOC element has the following attributes:

Attributes:

Note:
When a Global Project is created, an initial Location element is created with a NAME of /PROJECTHUB and a LOCID of ‘HUB’. Its LINIT flag is set to true.

Note:
Do not allow locked files in the current Project to be overwritten during copying by Global updates if other Projects are using the current Project as a foreign one. This is because DB readers in the other Projects are valid Users, even though they are not recorded as Users in the current Project.

DBALL Element

Attributes:

LNKLI Element

The LNKLI element contains a list of link elements LNK which specify the connections between pairs of Locations.

Not used at this release.

Attributes:

LNK Element

Not used at this release.

Attributes:

GSTWLD Element

Any existing stamps in the Standard System DB are copied to the Global Stamp World element and deleted from the System DB.