Range Considerations - Keithley 2651A Reference Manual

Section 2: General operation

Range considerations

The source range and measure range settings can interact depending on the source function.
Additionally, the output state (on/off) can affect how the range is set. The following table describes
these interactions:
If...
The source function is
the same as the
measurement function
(for example, sourcing
voltage and
measuring voltage)
A source or
measurement range
for a function is
explicitly set
The range is changed
with the output off
The range is changed
with the output on
Source autoranging is
enabled
Measure autoranging
is enabled
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Model 2651A High Power System SourceMeter® Instrument Reference Manual
Then... Notes
The measurement The setting for the voltage measure range is retained and
range is locked to be used when the source function is changed to current, and the
present voltage measurement range will be used.
the same as the
source range.
Model 2651A example:
smua.source.func = smua.OUTPUT_DCVOLTS
smua.source.rangev = 1
smua.measure.rangev = 10
-- will print 1, to match source range
print(smua.measure.rangev)
smua.source.func = smua.OUTPUT_DCAMPS
-- will print 10, the user's range
print(smua.measure.rangev)
Autoranging for that Autoranging is controlled separately for each source and
function is disabled. measurement function: source voltage, source current,
measure voltage, and measure current. Autoranging is
enabled for all four by default.
Hardware settings will Querying will return the range setting that will be used once
not be updated. the output is turned on.
The new setting will N/A
take effect
immediately.
The unit will not return When the output is turned on, the display will show a series of
an error until the question marks: ???.???
output is turned on.
Range is changed Querying the range after the measurement is taken will return
only when a the range that the unit chose.
measurement is
taken.
2651A-901-01 Rev. A / March 2011