Keithley 6220

13-6 DISPlay, FORMat, and SYSTem Key-Press Codes Model 6220/6221 Reference Manual
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IEEE-754 double precision format
REAL, 64, or DREal selects the binary IEEE754 double precision data format and
is shown in Figure 13-2B (normal byte order shown). This format is similar to the
single precision format except that it is 64 bits long.
Figure 13-2
IEEE-754 data formats
s
#0
7 0707070
ef
Header
Byte 1 Byte 2 Byte 3 Byte 4
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.
A) Single precision data format (32 data bits)
s
#0
7 0707070
ef
Header
Byte 1 Byte 2 Byte 7 Byte 8
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.
B) Double precision data format (64 data bits)
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