User`s manual

8 Serial Port I/O
8-64
The Record File Format
The record file is an ASCII file that contains a record of one or more serial port
sessions. You specify the amount of information saved to a record file with the
RecordDetail property.
RecordDetail can be compact or verbose. A compact record file contains the
number of values written to the device, the number of values read from the
device, the data type of the values, and event information. A verbose record file
contains the preceding information as well as the data transferred to and from
the device.
Binary data with precision given by
uchar, schar, (u)int8, (u)int16 or (u)int32
is recorded using hexadecimal format. For example, if the decimal value 255 is
read from the instrument as a 16-bit integer, the hexadecimal value 00FF is
saved in the record file. Single- and double-precision floating-point numbers
are recorded as decimal values using the
%g format, and as hexadecimal values
using the format specified by the IEEE Standard 754-1985 for Binary
Floating-Point Arithmetic.
The IEEE floating-point format includes three components: the sign bit, the
exponent field, and the significand field. Single-precision floating-point values
consist of 32 bits. The value is given by
Double-precision floating-point values consist of 64 bits. The value is given by
The floating-point format component, and the associated single-precision and
double-precision bits are given below.
Bit 1 is the left-most bit as stored in the record file.
Component Single-Precision Bits Double-Precision Bits
sign
11
exp 2-9 2-12
significand 10-32 13-64
value 1–()
sign
2
exp-127
()1.significand()=
value 1–()
sign
2
exp-1023
()1.significand()=