IfcLightDistributionCurveEnum

BACnet MVD

#### IfcLightDistributionCurveEnum

Natural language names

| Light Distribution Curve Enum
| Enumération des courbes de distribution lumineuse

##### Semantic definitions at the type

Type definition

There are three kinds of light distribution curves, see Figure 350.

> NOTE The classification as type A, B, C is according to Standard CEN TC 169, prEN 13032-1, CIE 121:

B-Type System | C-Type System

Figure 350 — Light distribution curves

> HISTORY New enumeration in IFC2x2.

Enumeration definition

Constant | Description
--- | ---
TYPE_A | Type A is basically not used. For completeness the Type A Photometry equals the Type B rotated 90° around the Z-Axis counter clockwise.
TYPE_B | Type B is sometimes used for floodlights. The B-Plane System has a horizontal axis. B-Angles are valid from -180° to +180° with B 0° at the bottom and B180°/B-180° at the top, β-Angles are valid from -90° to +90°.
TYPE_C | Type C is the recommended standard system. The C-Plane system equals a globe with a vertical axis. C-Angles are valid from 0° to 360°, γ-Angles are valid from 0° (south pole) to 180° (north pole).
NOTDEFINED |

##### Formal representations

XML Specification
`<xs:simpleType name="IfcLightDistributionCurveEnum">
<xs:restriction base="xs:string">
<xs:enumeration value="type_a"/>
<xs:enumeration value="type_b"/>
<xs:enumeration value="type_c"/>
<xs:enumeration value="notdefined"/>
</xs:restriction>
</xs:simpleType>
`
EXPRESS Specification
`TYPE IfcLightDistributionCurveEnum = ENUMERATION OF (
TYPE_A,
TYPE_B,
TYPE_C,
NOTDEFINED);
END_TYPE;

EXPRESS-G diagram

`

References: IfcLightIntensityDistribution

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