# Synchronize data automatically

Aim

To synchronize EthoVision XT data and external data using the synchronization signal sent to the external DAQ system during live tracking.

Procedure

1.Import the external data that was simultaneously acquired during live tracking into EthoVision XT.

2.In the Import External Data window, you see:

one or more 'Normal Data Sets' (indicated by a diagram icon).

one or more 'Sync Data Sets' (indicated by a clock icon).

The Link Variable cell for a Sync Data Set shows which Trial was acquired simultaneously with the external data.

A Sync Data Set is automatically detected when you use the Time Code (TCAP) synchronization signal. When you use the On-Off signal, it may be necessary to select Sync Data Set from the context menu to tell EthoVision XT that the data set contains the synchronization signal:

In the Import External Data window, right-click the Data Set that you want to change to Sync Data Set and select Sync Data Set.

3.If necessary, adjust the Synchronization Settings (this step) or proceed to step 4.

Click the Synchronization Settings button to open the Synchronization Settings window. Here you can set values for the following parameters that determine how the information from the synchronization signal is extracted from the imported external data file (default values in brackets):

▪Number of offset values (10) is the number time points in the synchronization signal used to calculate offset points. This only applies to the Time Code signal. The offset values are used for the calculation of average offset and gain. A higher value increases the accuracy of synchronization, but also increases calculation time.

▪Smoothing factor (1) is the number of sample points over which an average signal level is calculated. A higher value reduces spikes on the signal, but also reduces the time accuracy of the synchronization. The Smoothing Factor is used for both On-Off and Time Code signal.

▪Signal-to-noise-ratio (50) determines the tolerance for detecting high-low signal transitions. A higher value increases this tolerance, but also increases the chance of detecting false transitions.

▪Number of samples prescan TCAP (180000) is the maximum number of sample points used for auto-detection of a Time Code signal in the DAQ samples. For example, 180 seconds at 1 kHz or 30 minutes at 100 Hz. This setting only applies when you started your DAQ system before you started tracking in EthoVision XT.

Click in the boxes to set a value for each of the parameters. Click Defaults if you want to return to the default values or click OK to finish.

4.In the Import External Data window, select one or more Data Sets you want to link, click on one of the Data Sets with the left mouse-button, keep the left mouse-button pressed and link the Data Sets with a drag-and-drop action to the corresponding Trial, Arena or Subject.

5.Click Import to finish linking the Data Sets.

Notes

▪The Synchronization Settings button in the Import External Data window is only available if Enable DAQ co-acquisition is selected in the Experiment Settings.

▪The information in the synchronization signal is sampled by the DAQ system. During import into EthoVision XT some digital signal processing takes place to deal with noise, signal distortion, spikes etc. This processing is determined by the Synchronization Settings above.

See also

▪Enable DAQ co-acquisition in EthoVision XT

▪Connect EthoVision XT to the DAQ system