Keithley 6514 Instruction Manual page 209

B) FETCh?
This command requests the latest post-processed readings. After sending this command and
addressing Model 6514 to talk, the readings are sent to the computer. This command does not
affect the instrument setup.
This command does not trigger a measurement. The command simply requests the last group
of readings. Note that this command can repeatedly return the same readings. Until there is a
new reading(s), this command continues to return the old reading(s). If your application requires
a "fresh" reading, use the :READ? command.
This command is automatically asserted when the :READ? or :MEASure? command is sent.
C) READ?
This command is used to trigger and acquire readings. The number of readings depends on
how the trigger model is configured. For example, if configured for 20 measurements (arm count
1, trigger count 20), 20 sets of readings will be acquired.
When this command is sent, the following commands execute in the order they are presented:
• INITiate
• FETCh?
If the instrument is in the idle state, INITiate takes the instrument out of idle to perform the
programmed number measurements. If the instrument is not in the idle state, execution of this
command will wait until it goes back into idle.
The FETCh? command is executed to acquire the reading(s). The readings are sent to the
computer when Model 6514 is addressed to talk.
NOTE
If the instrument is programmed to perform an infinite number of measurements (arm
count or trigger count set to infinite), you cannot use the READ? command to trigger
and acquire readings. Use INITiate to start (trigger) the measurement process, send
ABORt to abort the measurement process, and then use SENSe:DATA[:LATest]? to
return the last (latest) reading.
D) MEASure[:<function>]?
<function> = VOLTage[:DC]
CURRent[:DC]
RESistance
CHARge
This command combines all of the other signal oriented measurement commands to perform
a "one-shot" measurement and acquire the reading.
When this command is sent, the following commands execute in the order that they are
presented.
• CONFigure:<function>
• READ?
When :CONFigure is executed, the instrument goes into a "one-shot" measurement mode.
See CONFigure for details.
SCPI Signal Oriented Measurement Commands
Request latest reading
Trigger measurement(s) and request reading(s)
Configure and perform "one-shot" measurement
Measure voltage
Measure current
Measure resistance
Measure charge
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