Keithley 6482, Reference Manual

Page: 191 / 350

15-4 Return to Section Topics 6482-901-01 Rev. A / August 2012
Section 15: SCPI Measurement Commands Model 6482 Dual-Channel Picoammeter / Voltage Source Reference Manual
READ?
Description 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
source and measure operations (arm count 1, trigger count 20), then 20 sets of
readings will be acquired after the Model 6482 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 an idle
state.
NOTE
:READ? is illegal when the :ARM:SOUR BUS command is in effect. See Section 8 ,
“Triggering,” for details.
After all source and measure operations are completed, the Model 6482 goes
back into an idle state, and then the :FETCh? command is executed. The
readings are sent to the computer and displayed when the Model 6482 is
addressed to talk.
NOTE
The :FORM:ELEM command controls the reading source. To access channel 1 readings,
send :FORM:ELEM CURR1 before sending :READ?. To access channel 2 readings,
send :FORM:ELEM CURR2 before using :READ?. See
Section 16 , “FORMat
subsystem,” for details.
READ? will work with the output off. If in the sweep mode with a trigger count >1,
the source value on the display will update; however, the actual output will be 0 V.
If automatic output-off is enabled (:SOURce1:CLEar:AUTO ON or
:SOURce2:CLEar:AUTO ON), then the corresponding output will automatically
turn on at the beginning of each SDM (source-delay-measure) cycle and turn off
after each measurement.
NOTE See Appendix B for a detailed explanation on how data flows through the various
operation blocks of the Model 6482 . It clarifies the type of readings that are acquired by
the various commands to read data.
MEASure[:CURRent[:DC]]?
Parameters CURRent[:DC] Amps function
Description This command combines other signal-oriented measurement commands to
perform a single measurement and acquire the reading.
When this command is sent, the following commands execute in the order that
they are presented.
• :CONFigure:CURRent[:DC]
• :READ?
When :CONFigure is executed, the instrument goes into a single measurement
mode. See
“CONFigure:CURRent[:DC]” for more details.
NOTE :MEAS? is illegal when the :ARM:SOUR BUS command is in effect. See Section 8 ,
“Triggering,” for details.