IfcDistributionControlElement

Definition from IAI: The distribution element IfcDistributionControlElement defines occurrence elements of a building automation control system that are used to impart control over elements of a distribution system.

This class defines elements of a building automation control system. These are typically used to control distribution system elements to maintain temperature, humidity, pressure, flow, power, lighting levels, etc., through the modulation, staging or sequencing of mechanical or electrical devices. The three general functional categories of ControlElements as defined for this release of the IFC model are as follows:

- Impart control over flow control elements (IfcFlowController) in a distribution system such as dampers, valves, relays, etc., typically through the use of actuation (IfcActuator: See IfcHvacDomain schema).
- Sensing elements (IfcSensor: See IfcHvacDomain schema) that measure changes in the controlled variable (e.g., temperature, humidity, pressure, flow, etc.).
- Controllers (IfcController: See IfcHvacDomain schema) typically classified according to the control action they seek to perform and generally responsible for making decisions about the elements under control.

Since this class and its subtypes typically relate to many different distribution flow elements (IfcDistributionFlowElement), the objectified relationship IfcRelFlowControlElements has been provided to relate control and flow elements as required.

> HISTORY: New entity in IFC R2.0.

Geometry Use Definitions

The geometric representation of IfcControlElement is given by the IfcProductDefinitionShape, allowing multiple geometric representations. Included are:

Local Placement

The local placement is defined in the supertype IfcProduct. It is defined by a subtype of IfcObjectPlacement which can define an absolute placement, relative placement, or grid reference, with each defining the local coordinate system referenced by all geometric representations. The PlacementRelTo relationship of IfcLocalPlacement, if given, shall point to the same IfcSpatialStructureElement which is used in the ContainedInStructure inverse attribute, or to a referenced spatial structure element at a higher level. If the relative placement is not used, the absolute placement is defined within the world coordinate system.

Informal propositions for local placement:

1. If the LocalPlacement is specified, then all aggregated components should use this placement as their relative placement.

Standard Geometric Representation

Currently, the use of attribute driven geometry for this class is not supported. The standard geometric representation is defined using explicit geometry.

B-Rep Representation

The faceted B-Rep capabilities (with or without voids) shall be supported for B-Rep representation.

EXPRESS specification:

ENTITY IfcDistributionControlElement
SUBTYPE OF ( | IfcDistributionElement);
ControlElementId | : | OPTIONAL IfcIdentifier;
INVERSE
AssignedToFlowElement | : | SET [0:1] OF IfcRelFlowControlElements FOR RelatedControlElements;
END_ENTITY;

Attribute definitions:

ControlElementId | : | The ControlElement Point Identification assigned to this control element by the Building Automation System.
AssignedToFlowElement | : | Reference through the relationship object to related distribution flow elements.

Inheritance graph

ENTITY IfcDistributionControlElement;
ENTITY IfcRoot;
GlobalId | : | IfcGloballyUniqueId;
OwnerHistory | : | IfcOwnerHistory;
Name | : | OPTIONAL IfcLabel;
Description | : | OPTIONAL IfcText;
ENTITY IfcObjectDefinition;
INVERSE
HasAssignments | : | SET OF IfcRelAssigns FOR RelatedObjects;
IsDecomposedBy | : | SET OF IfcRelDecomposes FOR RelatingObject;
Decomposes | : | SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;
HasAssociations | : | SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject;
ObjectType | : | OPTIONAL IfcLabel;
INVERSE
IsDefinedBy | : | SET OF IfcRelDefines FOR RelatedObjects;
ENTITY IfcProduct;
ObjectPlacement | : | OPTIONAL IfcObjectPlacement;
Representation | : | OPTIONAL IfcProductRepresentation;
INVERSE
ReferencedBy | : | SET OF IfcRelAssignsToProduct FOR RelatingProduct;
ENTITY IfcElement;
Tag | : | OPTIONAL IfcIdentifier;
INVERSE
HasStructuralMember | : | SET OF IfcRelConnectsStructuralElement FOR RelatingElement;
FillsVoids | : | SET [0:1] OF IfcRelFillsElement FOR RelatedBuildingElement;
ConnectedTo | : | SET OF IfcRelConnectsElements FOR RelatingElement;
HasCoverings | : | SET OF IfcRelCoversBldgElements FOR RelatingBuildingElement;
HasProjections | : | SET OF IfcRelProjectsElement FOR RelatingElement;
ReferencedInStructures | : | SET OF IfcRelReferencedInSpatialStructure FOR RelatedElements;
HasPorts | : | SET OF IfcRelConnectsPortToElement FOR RelatedElement;
HasOpenings | : | SET OF IfcRelVoidsElement FOR RelatingBuildingElement;
IsConnectionRealization | : | SET OF IfcRelConnectsWithRealizingElements FOR RealizingElements;
ProvidesBoundaries | : | SET OF IfcRelSpaceBoundary FOR RelatedBuildingElement;
ConnectedFrom | : | SET OF IfcRelConnectsElements FOR RelatedElement;
ContainedInStructure | : | SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements;
ENTITY IfcDistributionElement;
ENTITY IfcDistributionControlElement;
ControlElementId | : | OPTIONAL IfcIdentifier;
INVERSE
AssignedToFlowElement | : | SET [0:1] OF IfcRelFlowControlElements FOR RelatedControlElements;
END_ENTITY;