Keithley 2600a series, Reference Manual, Page: 126 / 696

6-4 Return to Section Topics 2600AS-901-01 Rev. B / September 2008
Section 6: Range, Digits, Speed, Rel, and Filters Series 2600A System SourceMeter® Instruments Reference Manual
5. Use EXIT to back out of the menu structure.
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.
If the source function is the same as the measurement function (for example, sourcing voltage and
measuring voltage), the measurement range is locked to be the same as the source range.
However, the setting for the voltage measure range is retained and used when the source function
is changed to current, and the present voltage measurement range will be used.
2601A/2602A Example:
smua.source.func = smua.OUTPUT_DCVOLTS
smua.source.rangev = 1
smua.measure.rangev = 6
-- will print 1, to match source range
print(smua.measure.rangev)
smua.source.func = smua.OUTPUT_DCAMPS
-- will print 6, the user's range
print(smua.measure.rangev)
Explicitly setting either a source or measurement range for a function will disable auto ranging for
that function. Auto ranging is controlled separately for each source and measurement function:
source voltage, source current, measure voltage, and measure current. Auto ranging is enabled
for all four by default.
Changing the range while the output is off will not update the hardware settings, but querying will
return the range setting that will be used once the output is turned on. Setting a range while the
output is on will take effect immediately.
With source auto ranging enabled, the output level controls the range. Querying the range after the
level is set will return the range the unit chose as appropriate for that source level.
The Series 2600A allows you to send ICL command values that may be out of range when auto
range is off. An example is sending 1A on the 100mA range. The unit does not error check until the
output is turned on. In this situation, the display will show a series of question marks:
???.???
With measure auto ranging enabled, the range will be changed only when a measurement is
taken. Querying the range after a measurement will return the range selected for that
measurement.
Range programming
Range commands
Table 6-2 summarizes the commands necessary to control measure and source ranges. See
Section 19 for more details on these commands.