GUIDs

Functionality is available to import several versions of an IFC model into an AVEVA E3D Design project. This might mean that there are several incarnations of the same elements sharing a GUID. IFC Unique Identifiers (GUIDs) should, as far as possible, be stable and unchanging over multiple exports.

In E3D Design this is done by means of the UUIDIA attribute, and the IFCUID and MSGUID pseudo-attributes. UUIDIA is available on many significant elements including SITE, ZONE, EQUI, SUBE, STRU, FRMW, SBFR, PIPE, BRAN, VOLM, SVOLM, and a number of others.

IFCUID and MSGUID is available on elements with a set UUIDIA, and also on elements below these elements in the hierarchy. For example, a VALVE beneath a PIPE with a set UUIDIA will have a stable GUID. Implied tube with such pipes and similar elements also effectively have a derived IFCUID/MSGUID.

These derived GUIDs are stable as long as the UUIDIA of the owning element is unchanged, and also that the type and REFNO of the element is unchanged. For example the following changes will change the IFCGUID and MSGUID of an element :

• Deleting the valve and replacing it with a new value with the same name (but a different REFNO)

• Database Listing elements without the “Use Same Reference Numbers” option, and reimporting

• Database reconfiguration without using the SAMEREF option

• Copying the element

• Inserting a new element before a piece of implied tube.

  Notes:
  Elements in an IFC file that do not correspond to a Dabacon element with a set IFCUID (for example IFC relationship elements, or where the Dabacon GUIDs were not set before export) are not persistent and will vary from export to export.

  Elements in the IFC file that should have a GUID but are not in the list will not be persistent and will vary from export to export.

Syntax

Command line syntax is available to set/unset the attributes, this calls on the core System to get a System GUID. For example: UUIDENT SET or UUIDENT UNSET.

Note:
If an element already has a set GUID, it cannot be overridden without deliberately un-setting it first. A message is displayed to this effect.