Emitters

Emitter Description

Emitters is the eighth child-element of GeneralDefinitions - the part in the XML where global and reusable elements are defined (imagine them as the building blocks of each luminaire).

Emitters define the radiation emitting parts of the luminaire. Be it in form of visible light of lamps or infrared EMR in case of motion detection sensors. However, they define not the lamps or sensors themselves. Emitters is the XML block, where many of these parts before come together. They are the parts of the luminaire description, where the measured photometry is finally placed. And get combined later in Variants with the geometrical definition of the luminaire:

`Emitter` root element

First of all you have to decide which type of emitter is required for your radiation emitting part. Each luminaire can contain multiple Emitter with different types. The following four types are available:

Emitter for a lamp that can be replaced in the luminaire ➜ choose ChangeableLightEmitter
Emitter for a lamp permanently installed in the luminaire ➜ choose FixedLightEmitter
Emitter for a multi channel light source in the luminaire ➜ choose MultiChannelLightEmitter
Emitter for a sensor ➜ choose SensorEmitter

important

One remarkable part of the XSD definition above is the fact, that GLDF accepts one or more ChangeableLightEmitter for each single Emitter. Or one or more FixedLightEmitter, MultiChannelLightEmitter or Sensor vice versa.

This does not mean that all these emitters are active simultaneously. Instead, they are interchangeable. The luminaire can operate in only one of these modes. Users in lighting calculation software, such as DIALux or RELUX, can switch between these modes as needed.

Examples

Example #1: Imagine a luminaire with emergency mode on one light source. In GLDF you can describe this with one emitter which contains two ChangeableLightEmitter child elements. One for normal mode and e.g. 500 lumen and another ChangeableLightEmitter for the same light output, but with emergency mode and 50 lumen. Both are not active at the same time but can operate in one mode or another.

Example #2: Imagine a luminaire measured/sold with two different lamps (and therefore probably different lighting, spectrum and electric characteristics). Again, you can describe this use case with multiple Equipments referenced inside one Emitter. This way they are meant to be interchangeable, rather than both active at same time on multiple light outputs.

Let's assume we would like to define a luminaire with a changeable light output. So for the moment a first Emitter XML example could look as follows:

<?xml version="1.0" encoding="UTF-8"?>
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Header/>
  <GeneralDefinitions>
    <!-- Content skipped for clarity -->
    <Emitters>
      <Emitter id="emitter1">
        <ChangeableLightEmitter>
          <!-- Changeable Emitter content skipped for now -->
        </ChangeableLightEmitter>
      </Emitter>
    </Emitters>
  </GeneralDefinitions>
  <ProductDefinitions/>
</Root>

`ChangeableLightEmitter`

An Emitter with child element(s) of type ChangeableLightEmitter is intended for light outputs with changeable lamps, as the name already says. Another functionality is to map multiple emergency modes or different control gears for one light output. All this variability can be achieved with this type. Choose the ChangeableLightEmitter as well, if you have defined Equipments previously (a combination of ChangeableLightSource with optional ControlGear). And you would like to reference them now.

XSD description

The only required element of a ChangeableLightEmitter is a PhotometryReference to define the light distribution curve of this light emitter. Let's expand the example to it in line 16:

<?xml version="1.0" encoding="UTF-8"?>
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Header/>
  <GeneralDefinitions>
    <Files>
      <File id="eulumdatNarrow" contentType="ldc/eulumdat" type="localFileName">50W_Narrow.ldt</File>
    </Files>
    <Photometries>
      <Photometry id="photometryNarrow">
        <PhotometryFileReference fileId="eulumdatNarrow"/>
      </Photometry>
    </Photometries>
    <Emitters>
      <Emitter id="emitterNarrow">
        <ChangeableLightEmitter>
          <PhotometryReference photometryId="photometryNarrow" />
        </ChangeableLightEmitter>
      </Emitter>
    </Emitters>
  </GeneralDefinitions>
  <ProductDefinitions/>
</Root>

At this point the example is already complete. The specification of a light source and an equipment are both optional. To create a valid ChangeableLightEmitter, it is sufficient to specify its light distribution curve only. In the form of a reference to an eulumdat or IES file to photometrically describe its light output characteristics.

But let's go one step further and describe a ChangeableLightEmitter with all available data:

<?xml version="1.0" encoding="UTF-8"?>
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Header/>
  <GeneralDefinitions>
    <Files>
      <File id="eulumdatNarrow" contentType="ldc/eulumdat" type="localFileName">MyNarrowLvk.ldt</File>
    </Files>
    <Photometries>
      <Photometry id="photometryNarrow">
        <PhotometryFileReference fileId="eulumdatNarrow"/>
      </Photometry>
    </Photometries>
    <LightSources>
      <ChangeableLightSource id="metalHalideLamp_1500lumen">
        <!-- Content skipped for clarity -->
      </ChangeableLightSource>
    </LightSources>
    <ControlGears>
      <ControlGear id="electronicControlGear">
        <!-- Content skipped for clarity -->
      </ControlGear>
    </ControlGears>
    <Equipments>
      <Equipment id="equipmentWithBallast_210w">
        <LightSourceReference changeableLightSourceId="metalHalideLamp_1500lumen"/>
        <ControlGearReference controlGearId="electronicControlGear"/>
        <RatedInputPower>210</RatedInputPower>
      </Equipment>
    </Equipments>
    <Emitters>
      <Emitter id="emitter1_Narrow">
        <ChangeableLightEmitter emergencyBehaviour="Combined">
          <Name>
            <Locale language="en">Spot narrow, round</Locale>
            <Locale language="de">Spot engstrahlend, rund</Locale>
          </Name>
          <PhotometryReference photometryId="photometryNarrow"/>
          <EquipmentReference equipmentId="equipmentWithBallast_210w" />          
        </ChangeableLightEmitter>
      </Emitter>
    </Emitters>
  </GeneralDefinitions>
  <ProductDefinitions/>
</Root>

We've defined

Line 6: A File reference to an Eulumdat photometry file named MyNarrowLvk.ldt (located inside the GLDF Container)
Line 9: A Photometry element referencing this Eulumdat file
Line 14: A ChangeableLightSource - let's assume this luminaire is sold with a metal halide lamp 200W
Line 19: A ControlGear. Let's further assume this metal halide lamp requires a ballast
Line 24: We combine the metal halide lamp with the ballast to an Equipment and say, it requires 210W in total
Line 31: The final part inside the general definition block: We reference the Equipment above together with the Photometry into a ChangeableLightEmitter. The part of the luminaire description, where the measured photometry is finally placed
Line 32: An emergencyBehaviour attribute to define, how this specific light output of the luminaire behaves in emergency lighting scenarios. Possible values are
- None ➜ This Emitter is intended for normal lighting only (which is also the default, if the attribute is missing)
- EmergencyOnly ➜ This Emitter is active during emergency lighting and inactive during normal lighting
- Combined ➜ This Emitter is intended for both, normal and emergency lighting scenarios
Line 33: A Name element, with Locales in English and German, to define, that this Emitter is named "Spot narrow, round". So users can work with this product in their preferred language and identify parts through a meaningful name

Later on in one last step inside the Variant element, we can bring this Emitter and a Geometry element together into a final product definition.

`FixedLightEmitter`

The difference between a FixedLightEmitter and a ChangeableLightEmitter is already in the name: It is intended for fixed light sources. Unlike classical lamps with sockets, a FixedLightSource is not intended to be replaced. Soldered LED modules are the usual use case. Therefore, the data model for a FixedLightEmitter is similar, but not the same.

The main differences are:

There is no Equipment reference anymore, since equipments represent a changeable construct of a lighting part in a luminaire. And therefore there is no possibility to reference a ChangeableLightSource anymore
Instead you have to define a FixedLightSource first. And reference it inside the FixedLightEmitter through a LightSourceReference element and the fixedLightSourceId attribute:

FixedLightEmitter FixedLightSource reference

Since the usual way of defining a ballast via Equipment is no longer possible, it can now also be referenced directly at the FixedLightEmitter ➜ see ControlGearReference element
The luminous flux of fixed lamps is logically no longer variable and must therefore also be specified directly on the FixedLightEmitter element ➜ see RatedLuminousFlux and RatedLuminousFluxRBG elements
This also applies to any impact of the ballast on the luminous flux ➜ see EmergencyBallastLumenFactor and EmergencyRatedLuminousFlux elements

Mandatory data example

Now let's define some FixedLightEmitter. Again, the simplest one first, with only mandatory data:

<?xml version="1.0" encoding="UTF-8"?>
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Header/>
  <GeneralDefinitions>
    <Files>
      <File id="ldcFile" contentType="ldc/eulumdat" type="localFileName">MyNarrowLvk.ldt</File>
    </Files>
    <Photometries>
      <Photometry id="photometryNarrow">
        <PhotometryFileReference fileId="ldcFile"/>
      </Photometry>
    </Photometries>
    <LightSources>
      <FixedLightSource id="ledModule_RGB">
        <Name>
          <Locale language="en">RGB dimmable</Locale>
          <Locale language="de">RGB dimmbar</Locale>
        </Name>
        <RatedInputPower>50</RatedInputPower>
      </FixedLightSource>
    </LightSources>
    <Emitters>
      <Emitter id="emitterNarrow">
        <FixedLightEmitter>
          <PhotometryReference photometryId="photometryNarrow"/>
          <LightSourceReference fixedLightSourceId="ledModule_RGB"/>
          <RatedLuminousFlux>450</RatedLuminousFlux>
        </FixedLightEmitter>
      </Emitter>
    </Emitters>
  </GeneralDefinitions>
  <ProductDefinitions/>
</Root>

Particularly noteworthy are

Line 6: A File reference to an Eulumdat photometry file named MyNarrowLvk.ldt (located inside the GLDF Container)
Line 9: A Photometry element referencing the photometry file through the fileId attribute
Line 14: A FixedLightSource with an input power of 50 W
Line 24: The final FixedLightEmitter with
- Line 25: A reference to the Photometry through the photometryId attribute
- Line 26: A reference to the FixedLightSource through the fixedLightSourceId attribute
- Line 27: A RatedLuminousFlux element saying, this combination emits 450 lumen

Complete data example

A complete FixedLightEmitter example adds an additional ballast, which shouldn't be required in most cases. And some data for emergency lighting scenarios, should the luminaire support them:

<?xml version="1.0" encoding="UTF-8"?>
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Header/>
  <GeneralDefinitions>
    <Files>
      <File id="ldcFile" contentType="ldc/eulumdat" type="localFileName">MyNarrowLvk.ldt</File>
    </Files>
    <Photometries>
      <Photometry id="photometryNarrow">
        <PhotometryFileReference fileId="ldcFile"/>
      </Photometry>
    </Photometries>
    <LightSources>
      <FixedLightSource id="ledModule_RGB">
        <Name>
          <Locale language="en">RGB dimmable</Locale>
          <Locale language="de">RGB dimmbar</Locale>
        </Name>
        <RatedInputPower>50</RatedInputPower>
      </FixedLightSource>
    </LightSources>
    <ControlGears>
      <ControlGear id="electronicControlGear">
        <!-- Content skipped for clarity -->
      </ControlGear>
    </ControlGears>
    <Emitters>
      <Emitter id="emitterNarrow">
        <FixedLightEmitter>
          <PhotometryReference photometryId="photometryNarrow"/>
          <LightSourceReference fixedLightSourceId="ledModule_RGB"/>
          <ControlGearReference controlGearId="electronicControlGear" />
          <RatedLuminousFlux>400</RatedLuminousFlux>
          <RatedLuminousFluxRGB>200</RatedLuminousFluxRGB>
          <EmergencyBallastLumenFactor>0.1</EmergencyBallastLumenFactor>
        </FixedLightEmitter>
      </Emitter>
    </Emitters>
  </GeneralDefinitions>
  <ProductDefinitions/>
</Root>

Compared to the first example, the following optional elements have been added:

Line 23/32: A ControlGear and a ControlGearReference with the corresponding controlGearId attribute
Line 34: An RatedLuminousFluxRGB element to declare the flux of the colored light only (the RGB module part)
Line 35: An additional EmergencyBallastLumenFactor. Its the ratio of the emergency luminous flux to the total luminous flux specified by RatedLuminousFlux. You can replace it with an EmergencyRatedLuminousFlux element instead, if an absolute flux value in emergency mode suits more.

Add these additional elements as applicable.

`MultiChannelLightEmitter`

The third emitter type is intended for light outputs of luminaires with multiple channels. It is also the simplest of the three, as the properties of the different channels are defined at the MultiChannelLightSource. In addition to the reference of a MultiChannelLightSource, the specification of a ControlGear is also possible, as well as the Emitter rotation (see below) and the Emitters display name.

`MultiChannelLightEmitter` XML example

An example of the MultiChannelLightEmitter illustrates well how the definition of the channels happens at the MultiChannelLightSource itself - in particular the photometry and spectrum of each channel:

<?xml version="1.0" encoding="UTF-8"?>
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Header/>  
  <GeneralDefinitions>
    <Files>
      <File id="photometryRedFile" contentType="ldc/eulumdat" 
            type="url">http://example.org/photometryRed.ldt</File>
      <File id="photometryGreenFile" contentType="ldc/eulumdat" 
            type="url">http://example.org/photometryGreen.ldt</File>
      <File id="photometryBlueFile" contentType="ldc/eulumdat" 
            type="url">http://example.org/photometryBlue.ldt</File>
      <File id="spectrumRedFile" contentType="spectrum/text" 
            type="url">http://example.org/spectrumRed.txt</File>
      <File id="spectrumGreenFile" contentType="spectrum/text" 
            type="url">http://example.org/spectrumGreen.txt</File>
      <File id="spectrumBlueFile" contentType="spectrum/text" 
            type="url">http://example.org/spectrumBlue.txt</File>
      <File id="lightSourceImage" contentType="image/jpg" 
            type="url">http://example.org/image.jpg</File>
    </Files>
    <Photometries>
      <Photometry id="photometryRed">
        <PhotometryFileReference fileId="photometryRedFile"/>
      </Photometry>
      <Photometry id="photometryGreen">
        <PhotometryFileReference fileId="photometryGreenFile"/>
      </Photometry>
      <Photometry id="photometryBlue">
        <PhotometryFileReference fileId="photometryBlueFile"/>
      </Photometry>
    </Photometries>
    <Spectrums>
      <Spectrum id="spectrumRed">
        <SpectrumFileReference fileId="spectrumRedFile"/>
      </Spectrum>
      <Spectrum id="spectrumGreen">
        <SpectrumFileReference fileId="spectrumGreenFile"/>
      </Spectrum>
      <Spectrum id="spectrumBlue">
        <SpectrumFileReference fileId="spectrumBlueFile"/>
      </Spectrum>
    </Spectrums>
    <LightSources>
      <MultiChannelLightSource id="multiChannelLightSource">
        <Name>
          <Locale language="en">RGB MultiChannel</Locale>
        </Name>
        <RatedInputPower>50</RatedInputPower>
        <LightSourceImages>
          <Image fileId="lightSourceImage" imageType="Product Picture"/>
        </LightSourceImages>
        <Channels>
          <Channel type="Red">
            <DisplayName>
              <Locale language="en">Red</Locale>
            </DisplayName>
            <SpectrumReference spectrumId="spectrumRed"/>
            <PhotometryReference photometryId="photometryRed"/>
            <RatedLuminousFlux>150</RatedLuminousFlux>
          </Channel>
          <Channel type="Green">
            <DisplayName>
              <Locale language="en">Green</Locale>
            </DisplayName>
            <SpectrumReference spectrumId="spectrumGreen"/>
            <PhotometryReference photometryId="photometryGreen"/>
            <RatedLuminousFlux>150</RatedLuminousFlux>
          </Channel>
          <Channel type="Blue">
            <DisplayName>
              <Locale language="en">Blue</Locale>
            </DisplayName>
            <SpectrumReference spectrumId="spectrumBlue"/>
            <PhotometryReference photometryId="photometryBlue"/>
            <RatedLuminousFlux>150</RatedLuminousFlux>
          </Channel>
        </Channels>
      </MultiChannelLightSource>
    </LightSources>
    <ControlGears>
      <ControlGear id="controlGear">
        <Name>
          <Locale language="en">Electronic ballast</Locale>
        </Name>
        <NominalVoltage>
          <VoltageRange>
            <Min>220</Min>
            <Max>230</Max>
          </VoltageRange>
        </NominalVoltage>
        <StandbyPower>5</StandbyPower>
        <Dimmable>true</Dimmable>
        <ColorControllable>true</ColorControllable>
      </ControlGear>
    </ControlGears>
    <Emitters>
      <Emitter id="emitter">
        <MultiChannelLightEmitter>
          <LightSourceReference multiChannelLightSourceId="multiChannelLightSource"/>
          <ControlGearReference controlGearId="controlGear"/>
        </MultiChannelLightEmitter>
      </Emitter>
    </Emitters>
  </GeneralDefinitions>
  <ProductDefinitions/>
</Root>

`SensorEmitter`

The SensorEmitter is the simplest form of an Emitter. And as the name suggests, it is not intended for light sources, but for the definition of radiation-emitting parts in form of a Sensor:

The XML example is correspondingly simple:

<?xml version="1.0" encoding="UTF-8"?>
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Header/>
  <GeneralDefinitions>
    <Files>
      <File id="sensorFile" contentType="sensor/sensldt" 
            type="localFileName">ir_sensor.txt</File>
    </Files>
    <Sensors>
      <Sensor id="sensor1">
        <SensorFileReference fileId="sensorFile"/>
      </Sensor>
    </Sensors>
    <Emitters>
      <Emitter id="sensorEmitter">
        <SensorEmitter>
          <SensorReference sensorId="sensor1"/>
        </SensorEmitter>
      </Emitter>
    </Emitters>
  </GeneralDefinitions>
  <ProductDefinitions/>
</Root>

Line 6: A File reference to a sensor file named ir_sensor.txt (located inside the GLDF Container)
Line 10: A Sensor definition referencing the sensor file through the fileId attribute
Line 16: A SensorEmitter definition referencing the sensor through the sensorId attribute

Emitter Rotation

One element we haven't covered yet is the Rotation on each of the Emitter types. However, this is only needed for edge cases. The two most common are

IES 90° rotation around G0 for street luminaires
Wall luminaires not measured in their position of usage

Rotation XML Example

<?xml version="1.0" encoding="UTF-8"?>
<Root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Header/>
  <GeneralDefinitions>
    <Files>
      <File id="streetLdcFile" contentType="ldc/ies" type="localFileName">street.ies</File>
    </Files>
    <Photometries>
      <Photometry id="streetPhotometry">
        <PhotometryFileReference fileId="streetLdcFile"/>
      </Photometry>
    </Photometries>
    <Emitters>
      <Emitter id="emitterWithRotation">
        <ChangeableLightEmitter>
          <Rotation>
            <X>0</X>
            <Y>0</Y>
            <Z>0</Z>
            <G0>90</G0>
          </Rotation>
          <PhotometryReference photometryId="streetPhotometry"/>
        </ChangeableLightEmitter>
      </Emitter>
    </Emitters>
  </GeneralDefinitions>
  <ProductDefinitions/>
</Root>

Emitter Description​

Emitter root element​

ChangeableLightEmitter​

XSD description​

FixedLightEmitter​

Mandatory data example​

Complete data example​

MultiChannelLightEmitter​

MultiChannelLightEmitter XML example​

SensorEmitter​

Emitter Rotation​

Rotation XML Example​