anchor.diff:    destructor Destroy; override;
     private
       fLinkLayers: TDictionary<Integer, TSesmiLinkLayer>;
  +    fTrackLayers: TDictionary<Integer, TSesmiTrackLayer>;
     protected
       fGUID: TGUID;
       fLive: Boolean;
  
positive.code:           value := aPayload.bb_read_double(aCursor);
            if fLinkLayers.TryGetValue(fieldInfo, layer) then
              layer.AddValue(timestamp, value);
          end;
        sensordata_linkid:
          begin
  
negative.code:   const aPayload: TByteBuffer; aCursor, aLimit: Integer);
  var
    layer: TSesmiLinkLayer;
    trackLayer: TSesmiTrackLayer;
    fieldInfo: UInt32;
    value, timestamp: Double;
    id: TWDID;
    sensorid: TGUID;
  begin
    timestamp := 0;
    while aCursor<aLimit do
  