User`s guide

Frequency Correction Data
Frequency Correction Data is identified in a time capture file with the following SDF_DATA_HDR
attributes:
dataType 34 (frequency corrections)
scanData 0
This data result contains the frequency domain corrections for the time capture data. It is the same size as
the instrument’s Spectrum data result. There is one of these results for each channel of a time capture.
Compressed Time Data
The compressed time data result in a time capture file contains a compressed representation of the entire
time capture file of each channel of time data. The time data is sampled and minimum and maximum
data values for each sampled region are stored for each data point. The compressed time data is identified
in a time capture file with the following SDF_DATA_HDR attributes:
dataType 45 (decimated time data) or
47 (compressed time data)
ydata_type SHORT16 or LONG32
yPerPoint 5
yIsComplex 0
scanData 0
The 5 values per point represent the following:
minimumrealvalue
minimum imaginary value
maximumrealvalue
maximum imaginary value
overload flag
Since the minimum/maximum values are in integer form, they can be scaled to volts using the same
mechanism as for scaling the time data (see above). If the dataType is 45 (decimated time data), then the
minimum values equal the maximum values since the data is decimated, not compressed. There is one of
these results for each channel of a time capture.
Standard Data Format (SDF)
B-37