User`s guide

The two ASCII characters at the beginning of the file identify it as an SDF file. The first character
is B, the second is \0 (null).
Special Fields in a Record
All records contain two special fields:
recordType: A number that uniquely identifies the type of data contained in the record.
recordSize: A number that specifies the length of the record (in bytes).
The following table shows you the recordType and recordSize values for the eight
common records:
Table B-1. Common Records
Name Description recordType
SDF 1
recordSize
(bytes)
SDF 2
recordSize
(bytes)
SDF 3
recordSize
(bytes)
SDF_FILE_HDR File Header
10 64 64 80
SDF_MEAS_HDR Measurement Header
11 102 140 156
SDF_DATA_HDR Data Header
12 114 134 148
SDF_VECTOR_HDR Vector Header
13 18 18 18
SDF_CHANNEL_HD
R
Channel Header
14 146 192 212
SDF_SCAN_STRUC
T
Scan Structure
15 Variable Variable Variable
SDF_XDATA_HDR X-axis Data
16 Variable Variable Variable
SDF_YDATA_HDR Y-axis Data
17 Variable Variable Variable
SDF_SCAN_BIG Scan Big
18 N/A N/A 20
SDF_SCAN_VAR Scan Variable
19 N/A N/A Variable
SDF_COMMENT_H
DR
Comment Header
20 N/A N/A Variable
Standard Data Format (SDF)
B-5