User manual

17-4 SCPI Signal Oriented Measurement Commands 2400 Series SourceMeter
®
User’s Manual
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 programmed 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 (current is not measured or
sourced).
NOTE The :FETCh? command is automatically asserted when the :READ? or
:MEASure? command is sent.
See Appendix C, “Data Flow,” 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.
[:SENSe[1]]:DATA[:LATest]?
Description This command works exactly like FETCh?, except that it returns
only the most recent reading.
:READ?
Description This command is used to trigger and acquire readings. The num-
ber of readings depends on how the trigger model is configured.
For example, if configured for 20 source-measure operations
(arm count 1, trigger count 20), then 20 sets of readings will be
acquired after the Source-Meter returns to the idle state.
When this command is sent, the following commands execute in
the order that they are presented:
• :INITiate
• :FETCh?
The :INITiate command starts operation by taking the instrument
out of idle.
After all source-measure operations are completed, the
SourceMeter goes back into idle at which time the :FETCh?
command is executed. The readings are sent to the computer
and displayed when the Source-Meter is addressed to talk.