User`s guide

Records—the Basic SDF Units
An SDF file consists of a number of smaller units called records: one “master,” called the File Header,
followed by a variable number of additional records. A record contains a group of related parameters and
data. For example, a record called the Channel Header contains all channel-specific information for one
of the channels used in a measurement.
There are eleven common records defined for SDF files:
File Header: Provides an index to the file.
Measurement
Header:
Contains settings of measurement parameters.
Data Header: Tells you how reconstruct one block of measurement results (x- and y-axis
values for every point of every trace).
Vector Header: Tells you which channel (or pair of channels) provided data for a single trace.
Channel Header: Contains channel-specific information for one channel used in the measurement.
Scan Structure: Tells you how vectors are organized in the Y-axis Data record when the
measurement includes multiple scans of data.
Scan Big: Extended scan header which tells how vectors are organized in the Y-axis data
record when the measurement may include more than 32767 scans of data.
Scan Variable: Contains a number that identifies every scan (scan time, RPM, or scan number).
Comment Header: Contains text information associated with the file.
X-axis Data: Contains the x-axis data needed to reconstruct any trace.
Y-axis Data:
Contains the y-axis data needed to reconstruct any trace.
Another record—the Unique record—makes the SDF file format flexible. The eight common record
types define parameters that are common to many instruments and systems. However, a particular
instrument or system may need to save and recall the states of additional parameters. These states can
reside in Unique records.
Standard Data Format (SDF)
B-2