This device can merge video and tracking data from multiple input channels into output channel(s). An output channel may contain a video stream from any of the input streams and tracking data from any input streams.
All input data is resampled at common time points. The sampling time points are defined by the timestamps of the video stream (if the output channel contains a video stream) or the first tool defined in the output channel (if the output channel does not contain video).
The mixer device is typically used for assigning position data to each image frame or create a single data channel that contains tracking data from multiple pose tracking devices.
Device configuration settings

Type = "VirtualMixer"
AcquisitionRate

Default = "50"
LocalTimeOffsetSec

Default = "0"
ToolReferenceFrame

Default = "Tracker"
Example configuration file PlusDeviceSet_fCal_Ultrasonix_L14-5_Ascension3DG_2.0.xml

<PlusConfiguration version="2.3">
  <DataCollection StartupDelaySec="1.0" >
    <DeviceSet 
      Name="fCal: Ultrasonix US (L14-5 probe) + Ascension3DG tracker (Probe, Reference, Stylus) - fCal Phantom 2.0"
      Description="Ascension3DG sensors should be plugged in to the Ascension3DG DriveBay mounted on Ultrasonix US in the following order from to leftmost slot (Transducer 1) to the right: 1 Probe, 2 Reference, 3 Stylus." />
    <Device
      Id="TrackerDevice" 
      Type="Ascension3DG" 
      LocalTimeOffsetSec="0.0" 
      FilterAcWideNotch="1"
      ToolReferenceFrame="Tracker" >
      <DataSources>
        <DataSource Type="Tool" Id="Probe" PortName="0"  />
        <DataSource Type="Tool" Id="Reference" PortName="1"  />
        <DataSource Type="Tool" Id="Stylus" PortName="2"  />
      </DataSources>
      <OutputChannels>
        <OutputChannel Id="TrackerStream" >
          <DataSource Id="Probe"/>
          <DataSource Id="Reference"/>
          <DataSource Id="Stylus"/>
        </OutputChannel>
      </OutputChannels>
    </Device>
    <Device
      Id="VideoDevice"
      Type="SonixVideo" 
      AcquisitionRate="30" 
      LocalTimeOffsetSec="-0.2976"
      IP="127.0.0.1"
      AutoClipEnabled="TRUE" >
      <DataSources>
        <DataSource Type="Video" Id="Video" PortName="B" PortUsImageOrientation="UF"  />
      </DataSources>
      <OutputChannels>
        <OutputChannel Id="VideoStream" VideoDataSourceId="Video"/>
      </OutputChannels>
    </Device>
    <Device 
      Id="TrackedVideoDevice" 
      Type="VirtualMixer" >
      <InputChannels>
        <InputChannel Id="TrackerStream" />
        <InputChannel Id="VideoStream" />
      </InputChannels>
      <OutputChannels>
        <OutputChannel Id="TrackedVideoStream"/>
      </OutputChannels>
    </Device>
  </DataCollection>
  <CoordinateDefinitions>
    <Transform From="Image" To="TransducerOriginPixel"
      Matrix="1 0 0 -410
              0 1 0 5
              0 0 1 0
              0 0 0 1"
      Date="2011.12.06 17:57:00" Error="0.0" />    
  </CoordinateDefinitions> 
  <Rendering WorldCoordinateFrame="Reference">
    <DisplayableObject Type="Model" ObjectCoordinateFrame="TransducerOrigin" Id="ProbeModel"
      File="Probe_L14-5_38.stl"
      ModelToObjectTransform="
        -1 0 0 29.7
        0 -1 0 1.5
        0 0 1 -14
        0 0 0 1" />
    <DisplayableObject Type="Model" ObjectCoordinateFrame="Reference" Id="Volume"/>
    <DisplayableObject Type="Model" ObjectCoordinateFrame="StylusTip" Id="StylusModel" File="Stylus_Example.stl" />
    <DisplayableObject Id="PhantomModel" Type="Model" ObjectCoordinateFrame="Phantom"
      Opacity="0.6"
      File="fCal_2.0.stl"
      ModelToObjectTransform="
        1 0 0 -35.0
        0 1 0 -10.0
        0 0 1 -5.0
        0 0 0 1" />
    <DisplayableObject Type="Image" ObjectCoordinateFrame="Image" Id="LiveImage"/>
  </Rendering>
<Segmentation
    ApproximateSpacingMmPerPixel="0.078"
    MorphologicalOpeningCircleRadiusMm="0.27"
    MorphologicalOpeningBarSizeMm="2.0"
    ClipRectangleOrigin="27 27" 
    ClipRectangleSize="766 562" 
    MaxLinePairDistanceErrorPercent="10"
    AngleToleranceDegrees="10"
    MaxAngleDifferenceDegrees="10"
    MinThetaDegrees="-70"
    MaxThetaDegrees="70"
    MaxLineShiftMm="10.0"
    ThresholdImagePercent="10"
    CollinearPointsMaxDistanceFromLineMm="0.6"
    UseOriginalImageIntensityForDotIntensityScore="FALSE"
    NumberOfMaximumFiducialPointCandidates="20"
  />  <PhantomDefinition>
    <Description
      Name="fCAL"
      Type="Multi-N"
      Version="2.0"
      WiringVersion="2.0"
      Institution="Queen's University PerkLab"
    />
    <Geometry>
      <Pattern Type="NWire">
        <Wire Name="7:G1_g1" EndPointFront="30.0 0.0 20.0" EndPointBack="30.0 40.0 20.0" />
        <Wire Name="8:L1_h1" EndPointFront="55.0 0.0 20.0" EndPointBack="35.0 40.0 20.0" />
        <Wire Name="9:M1_m1" EndPointFront="60.0 0.0 20.0" EndPointBack="60.0 40.0 20.0" />
      </Pattern>
      <Pattern Type="NWire">
        <Wire Name="4:G3_g3" EndPointFront="30.0 0.0 10.0" EndPointBack="30.0 40.0 10.0" />
        <Wire Name="5:H3_l3" EndPointFront="35.0 0.0 10.0" EndPointBack="55.0 40.0 10.0" />
        <Wire Name="6:M3_m3" EndPointFront="60.0 0.0 10.0" EndPointBack="60.0 40.0 10.0" />
      </Pattern>
      <Pattern Type="NWire">
        <Wire Name="1:H5_h5" EndPointFront="35.0 0.0 0.0" EndPointBack="35.0 40.0 0.0" />
        <Wire Name="2:L5_i5" EndPointFront="55.0 0.0 0.0" EndPointBack="40.0 40.0 0.0" />
        <Wire Name="3:M5_m5" EndPointFront="60.0 0.0 0.0" EndPointBack="60.0 40.0 0.0" />
      </Pattern>
      <Landmarks>
        <Landmark Name="#1" Position="104.3 5.0 20.0" />
        <Landmark Name="#2" Position="104.3 45.0 20.0" />
        <Landmark Name="#3" Position="104.3 45.0 0.0" />
        <Landmark Name="#4" Position="104.3 -5.0 0.0" />
        
        <Landmark Name="#5" Position="-34.3 45.0 15.0" />
        <Landmark Name="#6" Position="-34.3 -5.0 20.0" />
        <Landmark Name="#7" Position="-34.3 -5.0 0.0" />
        <Landmark Name="#8" Position="-34.3 45.0 0.0" />
      </Landmarks>      
      <Planes>
        <Plane Name="Superior" BasePoint="5.5 3.0 35.0" EndPoint1="135.0 3.0 35.0" EndPoint2="135.0 55.0 35.0" />
        <Plane Name="Inferior" BasePoint="5.5 55.0 0.0" EndPoint1="135.0 55.0 0.0" EndPoint2="135.0 5.5 0.0" />
        <Plane Name="Outside Unmarked" BasePoint="140.0 5.0 30.0" EndPoint1="140.0 50.0 30.0" EndPoint2="140.0 50.0 5.0" />
        <Plane Name="Inside Unmarked" BasePoint="125.0 40.0 30.0" EndPoint1="125.0 20.0 10.0" EndPoint2="125.0 40.0 10.0" />
        <Plane Name="Outside Marked" BasePoint="0.0 40.0 30.0" EndPoint1="0.0 40.0 5.5" EndPoint2="0.0 15.5 5.5" />
        <Plane Name="Outside Posterior" BasePoint="130.0 0.0 30.0" EndPoint1="20.0 0.0 30.0" EndPoint2="20.0 0.0 15.0" />
        <Plane Name="Inside Posterior" BasePoint="110.0 10.0 30.0" EndPoint1="40.0 10.0 30.0" EndPoint2="30.0 10.0 10.0" />
        <Plane Name="Outside Anterior" BasePoint="130.0 60.0 30.0" EndPoint1="20.0 60.0 30.0" EndPoint2="20.0 60.0 5.0" />
      </Planes>      
      <References>
        <Reference Name="#1" Position="104.3 5.0 20.0" />
        <Reference Name="#2" Position="104.3 45.0 20.0" />
        <Reference Name="#3" Position="104.3 45.0 0.0" />
        <Reference Name="#4" Position="104.3 -5.0 0.0" />
        <Reference Name="#5" Position="-34.3 45.0 15.0" />
        <Reference Name="#6" Position="-34.3 -5.0 20.0" />
        <Reference Name="#7" Position="-34.3 -5.0 0.0" />
        <Reference Name="#8" Position="-34.3 45.0 0.0" />
      </References>
    </Geometry>
  </PhantomDefinition>
<VolumeReconstruction OutputSpacing="0.5 0.5 0.5"
    ClipRectangleOrigin="0 0" ClipRectangleSize="820 616"
    Interpolation="LINEAR" Optimization="FULL" CompoundingMode="MEAN" FillHoles="OFF" />
  <fCal
    PhantomModelId="PhantomModel"
    ReconstructedVolumeId="Volume"
    TransducerModelId="ProbeModel"
    StylusModelId="StylusModel"
    ImageDisplayableObjectId="LiveImage"
    NumberOfCalibrationImagesToAcquire="200"
    NumberOfValidationImagesToAcquire="100"
    NumberOfStylusCalibrationPointsToAcquire="200"
    RecordingIntervalMs="100"
    MaxTimeSpentWithProcessingMs="70"
    ImageCoordinateFrame="Image"
    ProbeCoordinateFrame="Probe"
    ReferenceCoordinateFrame="Reference"
    TransducerOriginCoordinateFrame="TransducerOrigin"
    TransducerOriginPixelCoordinateFrame="TransducerOriginPixel"
    TemporalCalibrationDurationSec="10" 
    FixedChannelId="VideoStream" 
    FixedSourceId="Video"
    MovingChannelId="TrackerStream"
    MovingSourceId="ProbeToTracker"
    DefaultSelectedChannelId="TrackedVideoStream" 
    FreeHandStartupDelaySec="5" />
  <vtkPlusPivotCalibrationAlgo
    ObjectMarkerCoordinateFrame="Stylus"
    ReferenceCoordinateFrame="Reference"
    ObjectPivotPointCoordinateFrame="StylusTip" />
  <vtkPlusPhantomLandmarkRegistrationAlgo
    PhantomCoordinateFrame="Phantom"
    ReferenceCoordinateFrame="Reference"
    StylusTipCoordinateFrame="StylusTip" 
    DetectionTimeSec="1.0"
    StylusTipMaximumDisplacementThresholdMm="1.8" />
  <vtkPlusProbeCalibrationAlgo
    ImageCoordinateFrame="Image"
    ProbeCoordinateFrame="Probe"
    PhantomCoordinateFrame="Phantom"
    ReferenceCoordinateFrame="Reference" />
</PlusConfiguration>