Instruction manual

File Format
6-18
Data File
A/D-converted data is recorded as 2-byte integers between -32768 and +32767 in case of 16 bits A/D and
also recorded as 4-byte integers between –8388608 and +8388607 in case of 24 bits A/D. Negative numbers
are expressed as complements of 2.
The byte order is from the lower bytes to the higher bytes (Intel format)*1.
The sequence of data is as follows: first sampling channel order, second sampling channel order, ....., last
sampling channel order. This order is called the INTERLACED format*2, and the format name is recorded in
STORAGE_MODE in the header file.
The organization of a data file is shown in the following diagram. In this document a collection of data as
shown in the example is called one scan. A data file consists of scan repetitions.
Example
Data of 1 scan when recorded with a sampling frequency of 6 kHz:
Notes
*1: The byte order from the higher to the lower bytes is called the Motorola format. It is used in components
such as FFT analyzers that used Motorola CPUs and in workstations.
*2: The order of data of the SEQUENTIAL format is as follows: first channel sampling order, second channel
sampling order, ....., last channel sampling order.
ch 1
ch
2
ch
3
ch
4
ch
5
ch
6
ch
7
ch
8
Data Sequence
1/6000 sec