Additional SCPI Commands 15-5
SREal will select the binary IEEE754 single precision data format. Figure 15-2 shows the
normal byte order format for each data element. For example, if three valid elements are
specified, the data string for each reading conversion is made up of three 32-bit data blocks. Note
that the data string for each reading conversion is preceded by a 2-byte header that is the binary
equivalent of an ASCII # sign and 0.
Figure 15-2
IEE754 single precision data format (32 data bits)
DREal selects the binary IEEE754 double precision data format and is shown in Figure 15-3
(normal byte order shown). This format is similar to the single precision format except that it is
64 bits long.
Figure 15-3
IEEE754 double precision data format (64 data bits)
Byte 1
70
Header Byte 2
70
Byte 3
70
Byte 4
70
se f
#0
s = sign bit (0 = positive, 1 = negative)
e = exponent bits (8)
f = fraction bits (23)
Normal byte order shown. For swapped byte order,
bytes sent in reverse order: Header, Byte 4, Byte 3
Byte 2, Byte 1.
The Header is only sent once for each measurement conversion.
Byte 1
70
Header Byte 2
70
Byte 7
70
Byte 8
70
se f
# 0
s = sign bit (0 = positive, 1 = negative)
e = exponent bits (11)
f = fraction bits (52)
Normal byte order shown. For swapped byte order,
bytes sent in reverse order: Header, Byte 8,
Byte 7 .... Byte 1.
The Header is only sent once for each measurement conversion.
Bytes 3, 4, 5, and 6 not shown.
s = sign bit (0 = positive, 1 = negative)
e = exponent bits (11)
f = fraction bits (52)
Normal byte order shown. For swapped byte order,
bytes sent in reverse order: Header, Byte 8,
Byte 7 .... Byte 1.
The Header is only sent once for each measurement conversion.
Bytes 3, 4, 5, and 6 not shown.