User Manual

2400 Series SourceMeter
®
User’s Manual SCPI Signal Oriented Measurement Commands 17-3
• The count values of the Trigger Model are set to one.
• The Delay of the Trigger Model is set to zero.
• All math calculations are disabled.
• Buffer operation is disabled.
• Autozero is enabled.
• The source output will turn on.
WARNING When :CONFigure is sent, the output will turn on. Beware of
hazardous voltage that may be present on the output termi
-
nals.
NOTE This command is automatically asserted when the :MEASure? command
is sent.
Acquiring readings
:FETCh?
Description This query command requests the latest post-processed read-
ings stored in the sample buffer (see Appendix C, “Data Flow”).
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 continues to return the old
readings. For example, assume that the SourceMeter performed
20 source-measure operations. The :FETCh? command will
request the readings for those 20 source-measure operations. If
:FETCh? is sent while performing source-measure operations
(ARM annunciator 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 18, “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.