Keithley 6220, Reference Manual

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Model 6220/6221 Reference Manual DISPlay, FORMat, and SYSTem Key-Press Codes 13-5
Return to Section 13 topics
ASCII data format
The ASCII data format is in a direct readable form for the operator. Most program-
ming languages easily convert ASCII mantissa and exponent to other formats. How-
ever, some speed is compromised to accommodate the conversion.
Figure 13-1
shows an example ASCII string that includes all the data elements.
Figure 13-1 also shows the byte order of the data string. Data elements not speci-
fied by the :ELEMents command are not included in the string.
Figure 13-1
ASCII data format
IEEE-754 single precision format
REAL, 32, or SREal will select the binary IEEE-754 single precision data format.
Figure 13-2 A shows the normal byte order format for each data element. For
example, if three data elements are selected, the data string for each reading con-
version 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 13-2 does not show the byte for the terminator that
is attached to the end of each data string. Note that the byte order of the data
string can be sent in reverse order (see ”
FORMat:ELEMents <item list> ” on
page 13-7 ).
NOTE Regardless of which data format for output
strings is selected, the instrument will only re-
spond to input commands using the ASCII for-
mat.
+1.23456789E-03VDC, +0.000SECS, +1.2345e-06ADC, +1.23456789E-03VDC, xCMPL, +00001RDNG#
READing
TSTamp
UNITs SOURce COMPliance
2. Units for delta readings:
VDC = DC Volts
W = Ohms
W = Watts
S = Siemens
AVOLtage RNUMber
1
2
3
4
1. An overflow reading is displayed as +9.9E37.
3. The average voltage data element is only available for Differential Conductance.
4. For compliance, x = T or F:
TCMPL = In compliance
FCMPL = Not in compliance
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