Acquiring Readings; Fetch - Keithley 2500 User Manual

Models 2500 and 2502 User's Manual
WARNING
NOTE

Acquiring readings

FETCh?

Description
NOTE
NOTE
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com
When :CONFigure is sent, the outputs will turn on. Beware of hazard-
ous voltage that may be present on the output terminals.
This command is automatically asserted when the :MEASure? command is sent.
This query command requests the latest post-processed readings stored
in the sample buffer. After sending this command and addressing the
Model 2500 to talk, the readings are sent to the computer. This com-
mand does not affect the instrument setup.
This command does not trigger source and measure operations; it sim-
ply 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 Model 2500 performed 20 source and measure operations. The
:FETCh? command will request the readings for those 20 source and
measure operations. If :FETCh? is sent while performing source and
measure operations (ARM annunciator on), it will not be executed until
the Model 2500 goes back into idle.
The :FETCh? command is automatically asserted when the :READ? or
:MEASure? command is sent.
The readings that are acquired depend on which data elements are
selected (Section
readings take priority over source readings, and data from channels not
sourced or measured are assigned the NAN (not a number) value of
+9.91e37.
Send :FORM:ELEM CURR1 before :FETCh? for channel 1 readings or
:FORM:ELEM CURR2 for channel 2 readings.
See Appendix C for a detailed explanation on how data flows through the vari-
ous operation blocks of the Model 2500. It clarifies the types of readings that are
acquired by the various commands to read data.
SCPI Signal-Oriented Measurement Commands
17, "FORMat subsystem," "Data
16-3
elements"). Measure