Keithley 2016 - Border Command; Figure 5-3 IEEE754 Double Precision Data Format (64 Data Bits)

DREAL selects the binary IEEE-754 double precision data format and is
shown in Figure 5-3 (normal byte order shown). This format is similar to the
single precision format except that it is 64 bits long.
:BORDer command
:BORDer <name>
:FORMat:BORDer <name> Specify binary byte order
Parameters <name> = NORMal Normal byte order for binary formats
SWAPped Reverse byte order for binary formats
Query :BORDer? Query byte order
Description This command is used to control the byte order for the IEEE-754 binary
formats. For normal byte order, the data format for each element is sent as
follows:
Byte 1 Byte 2 Byte 3 Byte 4 (Single precision)
Byte 1 Byte 2 ... Byte 8 (Double precision
For reverse byte order, the data format for each element is sent as follows:
Byte 4 Byte 3 Byte 2 Byte 1 (Single precision)
Byte 8 Byte 7 ... Byte 1 (Double precision)
The “#0” header is not affected by this command. The header is always sent
at the beginning of the data string for each measurement conversion.
The ASCII data format can only be sent in the normal byte order. The
SWAPped selection is simply ignored when the ASCII format is selected.
Byte 1
70
Header Byte 2
70
Byte 7
70
Byte 8
70
se f
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.
# 0
F
igure 5-3
I
EEE754 double
p
recision data
f
ormat (64 data
bits)
entire data string.
5-32 SCPI Command Reference