Keithley 2002, User Manual

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IEEE-488 Reference
3-79
3.14
:FORMat subsystem
The commands for this subsystem are used to select the data format for transferring instrument
readings over the bus. The BORDer command and DATA command affect readings transferred
from the buffer ONLY. (i.e. SENSE: DATA? or CALC:DATA? is always be sent in ASCII.)
These commands are summarized in Table 3-6.
[:DATA] <type>[,length]
:FORMat[:DATA] <type>[,<length>] Specify data format
<type>[,<length>] = ASCii ASCII format
REAL,32 IEEE754 single precision format
REAL,64 IEEE754 double precision format
SREal IEEE754 single precision format
DREal IEEE754 double precision format
NOTES:
1. When using the ASCii, SREal or DREal parameter, a <length> parameter is not required.
2. If you do not use a <length> parameter with the REAL parameter, the <length> defaults to
32 (single precision format).
[:DATA]? Query data format
This command is used to select the data format for transferring readings over the bus. For every
reading conversion, the data string sent over the bus contains the elements specified by the
:ELEMents command. The specified elements are sent in a particular order.
The ASCII data format is in a direct readable form for the operator. Most BASIC languages eas-
ily convert ASCII mantissa and exponent to other formats. However, some speed is compro-
mised to accommodate the conversion. Figure 3-18 shows the ASCII format that includes all the
data elements.
Parameters
Query
Description
Figure 3-18
ASCII data format
Reading Time Stamp *
Reading
Number Channel
Number
±
1.2345678E
±
00NVDC,13:45:23.65 03-SEP-1993,
±
123456RDNG#, 01intchan
Mantissa Exponent Units
(reading
number)
Units:
VDC = DC Volts
VAC = AC Volts
ADC = DC Current
AAC = AC Current
OHM = 2-wire Resistance
OHM4W = 4-wire Resistance
HZ = Frequency
Status:
N = Normal
O = Overflow
R = Reference (Rel)
C = Temperature in
°
C
F = Temperature in
°
F
K = Temperature in K
00 = No channel
01 to 80 = Channel Number
Units:
intchan = Internal channel
extchan = External channel
Time Date
* Real time clock timestamp shown