Query Commands - Keithley 2002 Getting Started Manual

Query commands

With few exceptions, every SCPI command has a corresponding query. A command sets a
control point in the instrument; a query determines the present setting of the control point. The
query is simply the command name with a "?" attached.
Some commands are actions rather than control point settings. These commands have no que-
ry form. For example,
SENSe1:VOLTage:DC:REFerence:ACQuire
is an action command, not a setting, and so has no query form.
There are some queries that have no corresponding command. For example,
causes the instrument to return the latest reading. Of course, there is no corresponding command
to send a reading value into the instrument.
Default nodes
SCPI uses the concept of default nodes. Consider the example command tree shown previ-
ously in Figure 16. What is within square brackets is not necessary to send to the instrument, but
the instrument will accept it if you send it. Consider the
surement range. To set the Mode 2002 to measure 15VDC, any of the following commands
works:
SENSe1:VOLTage:DC:RANGe:UPPer 15
SENSe:VOLTage:DC:RANGe:UPPer 15
SENSe1:VOLTage:DC:RANGe 15
VOLTage:DC:RANGe:UPPer 15
VOLTage:DC:RANGe 15
These are shown in long form, but short forms could also be used.
IEEE-488 Bus Operation
SENSe1:DATA?
command, which sets the mea-
:UPPer
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