How can I Read and Access the Data of a DL850 FLD File?

The DL850 FLD file extension contains the acquired waveform data in IEEE 32-bit floating point format. You can analyze the floating point format using the low-level file I/O commands in MATLAB. FLD file format contains only the raw measurement values and does not contain any of the header information such as channel count, sample rate, timestamps, date, etc. 
The commands to open and read an FLD file in MATLAB is:
  • fileID = fopen('filename');
    include the single quotation marks
  • A = fread( fileID, inf, 'float');

The format and size of the data values in an FLD file is a float precision and 32-bits (8 bytes) respectively. Data values are stored in an M-by-N matrix, where M is the number of acquired data points and N is 1. In the Workspace Window, you can open the matrix A to view all the measurement values. Each data value is stored in a new row in the MxN matrix. If multiple channel or sub-channel waveforms are stored, the waveforms are not stored in a new column, instead it is appended to a new row at the end of the list.

For example, if 1 channel is saved with a record length of 10k then the FLD data will be in a 10010x1 matrix. If 2 channels are recorded with a record length of 10k, the file will be a 20020x1 matrix where the first data point of channel 2 begins at row 10011. 

In addition, the DL850 can save waveform data to a ASCII MATLAB type format. When the Waveform Save -> Data Type is in ASCII, you can select either the csv or MATLAB extension. Please note that the MATLAB extension is simply .TXT, a text file not the MATLAB .M. The only difference between an FLD and MATLAB .TXT file is the file size and header information. FLD file size is significantly smaller than a TXT file, since only the measurement values is saved for FLD files.
The MATLAB TXT file extension can be accessed using typical text file commands such as fileread, csvread, csvwrite, etc.

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