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SCPI Signal-Oriented Measurement Commands
16-3
WARNING
When :CONFigure is sent, the output will turn on. Beware of hazardous
voltage that may be present on the output terminals.
NOTE
This command is automatically asserted when the :MEASure? command is sent.
Acquiring readings
:FETCh?
Description
This query command requests the latest post-processed readings stored in
the sample buffer. See Appendix C. After sending this command and
addressing the SourceMeter to talk, the readings are sent to the computer.
This command does not affect the instrument setup.
This command does not trigger source-measure operations; it simply
requests the last available readings. Note that this command can repeatedly
return the same readings. Until there are new readings, this command con-
tinues to return the old readings. For example, assume that the
SourceMeter performed 20 source-measure operations. The :FETCh? com-
mand will request the readings for those 20 source-measure operations. If
:FETCh? is sent while performing source-measure operations (ARM annun-
ciator on), it will not be executed until the SourceMeter goes back into idle.
The readings that are acquired depend on which data elements are selected
(Section 17,
FORMat subsystem
,
Data elements
), and what the instrument is
presently programmed to source-measure. Measure readings take priority
over source readings, and functions not sourced or measured are assigned
the NAN (not a number) value of +9.91e37.
For example, assume that voltage, current and resistance readings are
selected as data elements, and the instrument is programmed to Source V
and Measure I. A reading string acquired by :FETch? will include the pro-
grammed
V-Source value and the I-Measure reading. The reading for resistance will
be NAN since resistance was not measured.
If the SourceMeter is instead programmed to Source V and Measure V, the
voltage reading will be the V-Measure reading (not the programmed
V-Source value). Both current and resistance readings will be NANs (cur-
rent is not measured or sourced).
NOTE
The :FETCh? command is automatically asserted when the :READ? or :MEASure?
command is sent.
NOTE
See Appendix C for a detailed explanation on how data flows through the various
operation blocks of the SourceMeter. It clarifies the types of readings that are
acquired by the various commands to read data.
Summary of Contents for 6430
Page 26: ......
Page 32: ......
Page 78: ...2 14 Connections ...
Page 98: ...3 20 Basic Source Measure Operation ...
Page 138: ...5 30 Source Measure Concepts ...
Page 156: ...6 18 Range Digits Speed and Filters ...
Page 168: ...7 12 Relative and Math ...
Page 176: ...8 8 Data Store ...
Page 202: ...9 26 Sweep Operation ...
Page 248: ...11 22 Limit Testing ...
Page 310: ...16 6 SCPI Signal Oriented Measurement Commands ...
Page 418: ...17 108 SCPI Command Reference ...
Page 450: ...18 32 Performance Verification ...
Page 477: ...A Specifications ...
Page 489: ...B StatusandErrorMessages ...
Page 498: ...B 10 Status and Error Messages ...
Page 499: ...C DataFlow ...
Page 503: ...D IEEE 488BusOverview ...
Page 518: ...D 16 IEEE 488 Bus Overview ...
Page 519: ...E IEEE 488andSCPI ConformanceInformation ...
Page 523: ...F MeasurementConsiderations ...
Page 539: ...G GPIB488 1Protocol ...
Page 557: ......