Section 7: TSP command reference
2606B System SourceMeter® Instrument Reference Manual
7-204
2606B-901-01 Rev. B / May 2018
smuX.measure.rangeY
This attribute contains the positive full-scale value of the measurement range for voltage or current.
Type
TSP-Link accessible
Affected by
Where saved
Default value
Attribute (RW)
Yes
Instrument reset
SMU reset
Recall setup
Saved setup
Voltage: 100e-3 (100 mV)
Current: 100e-3 (100 mA)
Usage
rangeValue
= smu
X
.measure.range
Y
smu
X
.measure.range
Y
=
rangeValue
rangeValue
Set to the maximum expected voltage or current to be measured
X
Source-measure unit (SMU) channel (for example,
smua.measure.rangev
applies to SMU channel A)
Y
SMU measurement function (
v
= voltage,
i
= current)
Details
Reading this attribute returns the positive full-scale value of the measurement range that the SMU is
currently using. Assigning a value to this attribute sets the SMU on a fixed range large enough to
measure the assigned value. The instrument will select the best range for measuring a value of
rangeValue
.
This attribute is primarily intended to eliminate the time that is required by the automatic range
selection performed by a measuring instrument. Because selecting a fixed range prevents
autoranging, an overrange condition can occur. For example, measuring 5.0 V on the 2 V range
causes an overrange. 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 measure range is retained. If the source function is changed (for example, from
sourcing voltage to sourcing current), the retained measurement range is used.
For example: Assume the source function is voltage. The source range is 1 V and you set the
measure range for 6 V. Since the source range is 1 V, the SMU performs voltage measurements on
the 1 V range. If you now change the source function to current, voltage measurements are made on
the 6 V range.
Explicitly setting a measure range will disable measure autoranging for that function. Autoranging is
controlled separately for each source and measurement function: source voltage, source current,
measure voltage and measure current. Autoranging is enabled for all four by default.
Changing the range while the output is off does not update the hardware settings, but querying
returns the range setting that will be used once the output is turned on. Setting a range while the
output is on takes effect immediately.
With measure autoranging enabled, the range is changed only when a measurement is taken.
Querying the range after a measurement returns the range selected for that measurement.
Example
smua.measure.rangev = 0.5
Selects the 1 V measurement range for SMU channel A.