Analog data (_a.tsv)

The analog data files contain the data of the analog capture. Each file contains the data from one analog board or EMG system. If there is only one source of analog data the file name ends with _a. If there are more than one source of analog data the files are numbered in the same order as they appear in the Data info window (_a_1, _a_2 and so on). There are two parts in the file: file header and data.

Header

The header is included when the Include TSV header option is checked in the TSV export settings.

In the file header, the variable names are written as one word (without any embedded spaces) followed by a tab character and the variable. Each variable is on a new line. The following variables are available in the file header:

  • FILE_VERSION
    Version number of export format, currently 2.0.0.

    FILE_VERSION is not included for versions earlier than 2.0.0.

  • TOT_NO_OF_CHAN
    Total number of channels in the exported file.

  • NO_OF_CALC_CHAN
    At present not used by QTM.

  • TIME_STAMP
    Date and time when the measurement was made. The date and time is followed by a tab character and then the timestamp in seconds from when the computer was started.

  • DESCRIPTION
    At present not used by QTM.

  • DATA_INCLUDED
    Type of data included in the file. Set to ANALOG by the QTM software

  • CHANNEL_NAMES
    List of tab-separated channel names. The number of names in the list corresponds to the number of channels given by the TOT_NO_OF_CHAN variable.

  • CHANNEL_GAIN
    List of tab-separated gains for each channel.
    At present they are all set to 1 by QTM.

  • CHANNEL_FREQUENCIES
    List of tab-separated analog sampling frequency values for each channel. The sampling frequencies can differ between channels.

  • CHANNEL_SAMPLE_COUNTS
    List of tab-separated sample count values for each channel. The number of samples can differ between channels.

  • FP_LOCATION, FP_CAL, FP_GAIN
    At present not used by QTM.

Data

The data part follows on a new line after FP_GAIN. The data of the analog channels are then stored in tab-separated columns, one column for each channel and one row per sample. The data is always saved with 6 digits.

For analog boards, the units of the exported data are in V. EMG data from integrated devices are exported in μV or mV, depending on the units provided by the device. For other data types from integrated devices, the units are converted to SI units associated with the data type.

There are two options in the TSV export which you can use to add more information to the file.

  • When the Export time data for every frame option is checked, each data column is preceded by two columns containing time data. The first column (SAMPLE) contains the sample number and the second column (TIME) contains the time in seconds relative to the start of the capture.

  • When the Write column header option is checked, a header is added above each column describing the contents of that column.