# Troubleshooting: External data

Issues

▪I cannot import external data, or I get an error message “a gap was detected in the raw data”

▪I imported the external data in EthoVision XT, but the values are missing

▪The external signals look “stretched”, or “compressed” over the time line.

I cannot import external data, or I get an error message “a gap was detected in the raw data”

Check carefully the prerequisites for importing external data. See Import external data: General information

tip Open one of your data files with the Notepad, and check whether there are irregularities in the file. Move the cursor between the numbers.

If there are blank spaces, not tabs between them, then in the import profile you must specify Space under Select data delimiters.

See also

▪Create a new custom import profile

▪Edit a custom import profile

I imported the external data in EthoVision XT, but the values are missing

▪case 1 In the Integrated Visualization, you see the original signal, but not the downsampled signal as defined in the Analysis Profile:

In most cases this could be due to the fact that the original signal is not in sync with the track data. Check the synchronization and re-import the files, or change the set of the external data by editing the start/end time.

See Synchronize data manually after import and Synchronize data automatically

case 2 The external data, both original and downsampled, are absent. When I try to re-synchronize the data, the Start date and time and the End date and time are identical.

This occurs when the original imported data (files with extension *.pbi) are not available, for example when they are stored on an external device. Make sure all files (experiment, and external data) are stored on the local drive.

The external signals look “stretched”, or “compressed” over the time line.

This may occur if one of the TCAP pulse trains, which encode the time used for alignment, is truncated. EthoVision XT calculates the average set using 10 values of time, and if one or more of the train pulses are incorrect, the data may be out of sync, or their form may look compressed or stretched.

In this example the last pulse train is shorter than the others:

1.Remove the imported data from the trial.

2.Open the original data (text) file and remove the last pulse train.

3.Re-import the edited data file.