Keithley 2600a series, Reference Manual, Page: 442 / 696

19-120 Return to Section Topics 2600AS-901-01 Rev. B / September 2008
Section 19: Remote Commands Series 2600A System SourceMeter® Instruments Reference Manual
smuX.measure.rangeY
X = SMU channel (a or b)
Y = SMU measure function (
v or i )
Where: v = voltage, i = current
Attribute Fixed measure range for voltage or current.
Default
100e-9 (2601A/2602A/2611A/2612A)
100e-12 (2635A/2636A)
TSP-Link
accessibility
This attribute can be accessed from a remote TSP-Link node.
Usage
rangeval = smuX.measure.rangev -- Reads voltage measure range.
smuX.measure.rangev = rangeval -- Writes voltage measure range.
rangeval = smuX.measure.rangei -- Reads current measure range.
smuX.measure.rangei = rangeval -- Writes current measure range.
rangeval
Set to the expected voltage or current to be measured.
Remarks • Reading this attribute returns the positive full-scale value of the measure range the SMU is
currently using.
• Assigning to this attribute sets the SMU on a fixed range large enough to measure the given
value. The instrument will select the best range for measuring a value of
rangeval
.
• This attribute is primarily intended to eliminate the time required by the automatic range selection
performed by a measuring instrument. Because selecting a fixed range will prevent auto-
ranging, an over-range condition can occur, for example, measuring 10.0V on the Model 2601A/
2602A 6V range or measuring 5.0V on the Model 2611A/2612A 2V range will cause an over-
range. The value 9.37 is returned when this occurs.
• 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.
• Model 2601A/2602A example: Assume the source function is voltage. The source range is 1V
and you set the measure range for 6V. Since the source range is 1V, the SMU will perform
voltage measurements on the 1V range. If you now change the function to current,
measurements will be performed on the 6V range.
• 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.
• 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.
Details See Range in Section 6 .
Also see
smuX.measure.autorangeY
Example Selects 1V measure range for Model 2601A/2602A SMU A:
smua.measure.rangev = 0.5