IFC 4.3.x development

6.2.3.8 IfcDistributionPort

Change log

IFC4

additionsattributesPredefinedType
additionsattributesSystemType

6.2.3.8.1 Semantic definitions at the entity

A distribution port is an inlet or outlet of a product through which a particular substance may flow.

Distribution ports are used for passage of solid, liquid, or gas substances, as well as electricity for power or communications. Flow segments (pipes, ducts, cables) may be used to connect ports across products. Distribution ports are defined by system type and flow direction such that for two ports to be connected, they must share the same system type and have opposite flow directions (one side being a SOURCE and the other being a SINK). Ports are similar to openings in that they do not have any visible geometry; such geometry is captured at the shape representation of the enclosing element or element type. Ports may have placement that indicates the position and orientation of the connection.

Ports are assigned the distribution systems in order to indicate its role in a particular system, e.g. cold water inlet.

HISTORY  New entity in IFC2x2

IFC4 CHANGE  Ports are now related to products and product types using the IfcRelNests relationship; use of IfcRelConnectsPortToElement is now reserved for dynamically attached ports (such as drilling a hole in a tank).

6.2.3.8.1 Attributes

# Attribute Type Description
IfcRoot
1 GlobalId IfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world.
2 OwnerHistory OPTIONAL IfcOwnerHistory Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object,

> NOTE  only the last modification in stored - either as addition, deletion or modification.

> IFC4 CHANGE  The attribute has been changed to be OPTIONAL.
3 Name OPTIONAL IfcLabel Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule.
4 Description OPTIONAL IfcText Optional description, provided for exchanging informative comments.
IfcObjectDefinition
HasAssignments SET [0:?] OF IfcRelAssigns FOR RelatedObjects Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups.
Nests SET [0:1] OF IfcRelNests FOR RelatedObjects References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only).

> IFC4 CHANGE  The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
IsNestedBy SET [0:?] OF IfcRelNests FOR RelatingObject References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types).

> IFC4 CHANGE  The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
HasContext SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object.

> IFC4 CHANGE  The inverse attribute datatype has been added.
IsDecomposedBy SET [0:?] OF IfcRelAggregates FOR RelatingObject References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts).

> IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
Decomposes SET [0:1] OF IfcRelAggregates FOR RelatedObjects References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only).

> IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
HasAssociations SET [0:?] OF IfcRelAssociates FOR RelatedObjects Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification.
IfcObject
5 ObjectType OPTIONAL IfcLabel The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED.
IsDeclaredBy SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.

> IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
Declares SET [0:?] OF IfcRelDefinesByObject FOR RelatingObject Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.

> IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
IsTypedBy SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type.

> IFC4 CHANGE  New inverse relationship, the link to IfcRelDefinesByType had previously be included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
IsDefinedBy SET [0:?] OF IfcRelDefinesByProperties FOR RelatedObjects Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object.

> IFC4 CHANGE  The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.
IfcProduct
6 ObjectPlacement OPTIONAL IfcObjectPlacement Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system.
7 Representation OPTIONAL IfcProductRepresentation Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement.
ReferencedBy SET [0:?] OF IfcRelAssignsToProduct FOR RelatingProduct Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product.
PositionedRelativeTo SET [0:?] OF IfcRelPositions FOR RelatedProducts
ReferencedInStructuresSET [0:?] OF IfcRelReferencedInSpatialStructure FOR RelatedElements
IfcPort
ContainedIn SET [0:1] OF IfcRelConnectsPortToElement FOR RelatingPort Reference to the element to port connection relationship. The relationship then refers to the element in which this port is contained.

> IFC4 CHANGE  The cardinality has been changed from 1:1 to 0:1. IFC4 DEPRECATION  The inverse relationship is deprecated for fixed ports due to deprecation of IfcRelConnectsPortToElement for this usage. Use inverse relationship Nests instead.
ConnectedFrom SET [0:1] OF IfcRelConnectsPorts FOR RelatedPort Reference to a port that is connected by the objectified relationship.
ConnectedTo SET [0:1] OF IfcRelConnectsPorts FOR RelatingPort Reference to the port connection relationship. The relationship then refers to the other port to which this port is connected.
IfcDistributionPort
8 FlowDirection OPTIONAL IfcFlowDirectionEnum Enumeration that identifies if this port is a Sink (inlet), a Source (outlet) or both a SinkAndSource.
9 PredefinedType OPTIONAL IfcDistributionPortTypeEnum
10 SystemType OPTIONAL IfcDistributionSystemEnum Enumeration that identifies the system type. If a system type is defined, the port may only be connected to other ports having the same system type.

6.2.3.8.2 Entity inheritance

dot_inheritance IfcDistributionPort IfcDistributionPort IfcPort IfcPort IfcDistributionPort->IfcPort IfcProduct IfcProduct IfcPort->IfcProduct IfcProduct_children 8 more... IfcProduct_children->IfcProduct IfcObject IfcObject IfcProduct->IfcObject IfcObject_children 5 more... IfcObject_children->IfcObject IfcObjectDefinition IfcObjectDefinition IfcObject->IfcObjectDefinition IfcContext IfcContext IfcContext->IfcObjectDefinition IfcRoot IfcRoot IfcObjectDefinition->IfcRoot IfcTypeObject IfcTypeObject IfcTypeObject->IfcObjectDefinition IfcPropertyDefinition IfcPropertyDefinition IfcPropertyDefinition->IfcRoot IfcRelationship IfcRelationship IfcRelationship->IfcRoot

6.2.3.8.3 Definitions applying to General Usage

6.2.3.8.3.1 Classification Association

Any object occurrence or object type can have a reference to a specific classification reference, i.e. to a particular facet within a classification system.

6.2.3.8.3.2 Identity

IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.

6.2.3.8.3.3 Object Predefined Type

6.2.3.8.3.4 Object Typing

Any object occurrence can be typed by being assigned to a common object type utilizing this concept. A particular rule, restricting the applicable subtypes of IfcTypeObject that can be assigned, is introduced by overriding this concept at the level of subtypes of IfcObject.

6.2.3.8.3.5 Object User Identity

An attribute Name and optionally Description can be used for all subypes of IfcObject. For those subtypes, that have an object type definition, such as ifcBeam - IfcBeamType, the common Name and optionally Description is associated with the object type.

6.2.3.8.3.6 Port Connectivity

IfcDistributionPort may be connected to other objects as follows using the indicated relationship:

  • IfcDistributionPort (IfcRelConnectsPorts) : Indicates a connection to another port having the same type and opposite flow direction. For port connections between elements, the RelatingPort is set to a port having FlowDirection=SOURCE and the RelatedPort is set to a port having FlowDirection=SINK. For aggregation scenarios, ports on a device may be mapped to aggregated devices within, in which case ports on the outer device indicate a single FlowDirection but have an additional connection internally to a port on an aggregated inner device. Refer to IfcUnitaryEquipment for an example.
  • IfcDistributionElement (through IfcRelConnectsPortToElement): For dynamic ports, indicates the containing element.

Figure 302 illustrates distribution port connectivity.

Connection Use Definition

Figure 302 — Distribution port connectivity

6.2.3.8.3.7 Port Nesting

Distribution ports are indicated on products and product types using the IfcRelNests relationship where RelatingObject refers to the enclosing IfcDistributionElement or IfcDistributionElementType respectively. The order of ports indicates logical ordering such within outlets, junction boxes, or communications equipment.

Ports may be further nested into sub-ports, for indicating specific connections on components or pins.

6.2.3.8.3.8 Product Assignment

The IfcDistributionPort may be assigned to the following entities using relationships as indicated:

Type
'IfcDistributionSystem'
'IfcDistributionCircuit'

6.2.3.8.3.9 Product Geometric Representation

The geometric representation of any IfcProduct is provided by the IfcProductDefinitionShape allowing multiple geometric representations. It uses the Product Placement concept utilizing IfcLocalPlacement to establish an object coordinate system, within all geometric representations are founded.

NOTE  A detailed specification of how to apply the local placement and which shape representaions are applicable is provided at the level of subtypes of IfcProduct and is further determined by the model view definition and implementer agreements.

6.2.3.8.3.10 Product Local Placement

The placement of a port indicates the position and orientation of how it may connect to a compatible port on another product. The placement shall be relative to the nesting IfcDistributionElement, IfcDistributionElementType, or enclosing IfcDistributionPort.

The Location is the midpoint of the physical connection, unless otherwise indicated by cardinal point on a material profile.

The Axis points in the direction of the physical connection away from the product if FlowDirection equals SOURCE (or SOURCEANDSINK or NOTDEFINED), or points opposite direction (to the product) if the FlowDirection equals SINK.

NOTE  The rationale for positioning the Axis in the direction of flow is to allow for the same geometry to be used, such as for connectors with polarized cross-section.

The RefDirection points in the direction of the local X axis of the material profile, where the local Y axis points up if looking towards the Axis where the local X axis points right.

Upon connecting elements through ports with rigid connections, each object shall be aligned such that the effective Location, Axis, and RefDirection of each port is aligned to be equal (with exception for circular profiles where the RefDirection need not be equal).

6.2.3.8.3.11 Product Placement

The Product Placement establishes the object coordinate system and is required, if a geometric shape representation is provided for this product.

6.2.3.8.3.12 Property Sets for Objects

PsetName
'Pset_DistributionPortCommon'
'Pset_DistributionPortTypeCable'
'Pset_DistributionPortTypeDuct'
'Pset_DistributionPortTypePipe'

6.2.3.8.3.13 Property Sets with Override

Any object occurrence can hold property sets, either directly at the object occurrence as element specific property sets, or at the object type, as type property sets. In this case, the properties that are provided to the object occurrence are the combinations of element specific and type properties. In case, that the same property (within the same property set, is defined both, in occurrence and type properties, the property value of the occurrence property overrides the property value of the type property.

6.2.3.8.3.14 Revision Control

Ownership, history, and merge state is captured using IfcOwnerHistory.

6.2.3.8.4 Formal representations

ENTITY IfcDistributionPort
 SUBTYPE OF (IfcPort);
	FlowDirection : OPTIONAL IfcFlowDirectionEnum;
	PredefinedType : OPTIONAL IfcDistributionPortTypeEnum;
	SystemType : OPTIONAL IfcDistributionSystemEnum;
END_ENTITY;