User manual

18-48 SCPI Command Reference 2400 Series SourceMeter
®
User’s Manual
Figure 18-1 also shows the byte order of the data string. Data ele-
ments not specified by the :ELEMents command are simply not
included in the string.
Keep in mind that the byte order can only be reversed for the binary
format. (See
“BORDer <name>,” page 18-54, command.)
Figure 18-1
ASCII data format
IEEE-754 single precision format
REAL,32, or SREal will select the binary IEEE-754 single precision
data format.
Figure 18-2 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 4-byte
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 18-2 does not show the byte for the terminator
that is attached to the end of each data string.
Figure 18-2
IEEE-754 single precision data format (32 data bits)
During binary transfers, never un-talk the SourceMeter until after the
data is read (input) to the computer. Also, to avoid erratic operation,
the readings of the data string (and terminator) should be acquired in
+1.000206E+00, +1.000000E-04, +1.000236E+04, +7.282600E+01, +4.813200E+04
Voltage
Reading
Current
Reading
Resistance
Reading
Time
Status
s
#0
70707070
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 and terminator are sent only once for each READ?.