Keithley 2016 - Fetch? Command

FETCh? command
:FETCh?
Description This query command requests the latest post-processed reading. After
sending this command and addressing the Model 2016 to talk, the reading is
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 available reading. Note that this command can repeatedly
return the same reading. Until there is a new reading, this command
continues to return the old reading. If your application requires a “fresh”
reading, use the :DATA:FRESh? command (see the SENSe Subsystem
command).
This command is asserted when the :READ? or :MEASure? command is
sent.
NOTE This command is valid while :OUTPut:MODE FIXED. Do not issue this command
while in sweep mode (:OUTPut:MODE:LIST). A value of +811 (not permitted in
LIST output mode) will be returned if this command is issued while in sweep mode.
Refer to Appendix B for a complete list of status and error messages.
NOTE If rapid external triggers are applied, the unit may not return date when using
:FETCh?
5-4 SCPI Command Reference