Keithley 2657A, Reference Manual, Page: 516 / 805

Model 2657A High Power System SourceMeter® Instrument Reference Manual Section 7: TSP command reference
2657A-901-01 Rev. B/December 2012 7-203
Details
This attribute is used with autoranging to put a lower bound on the range used. Since lower ranges generally
require greater settling times, setting a lowest range limit might make measurements require less settling time.
If the instrument is set to autorange and it is on a range lower than the one specified, the range is changed to the
lowRange
range value.
Example
smua.measure.lowrangei = 100e-9 Sets current low range for SMU channel A to
100 nA.
Also see
Range (on page 2-72)
reset() (on page 7-155)
setup.recall() (on page 7-175)
smuX.measure.autorangeY (on page 7-194)
smuX.reset() (on page 7-211)
smuX.measure.nplc
This command sets the integration aperture for measurements.
Type TSP-Link accessible Affected by Where saved Default value
Attribute (RW) Yes Instrument reset
SMU reset
Recall setup Saved setup 1.0
Usage
nplc
= smu
X
.measure.nplc
smu
X
.measure.nplc =
nplc
nplc
The integration aperture; set from 0.001 to 25
X
Source-measure unit (SMU) channel (for example,
smua.measure.nplc
applies
to SMU channel A)
Details
When making measurements, the SMU uses one of two types of analog-to-digital converters (ADC): integrating
or fast. This attribute controls the integration aperture for the integrating ADC. This attribute is not used when the
fast ADC is selected.
The integration aperture is based on the number of power line cycles (NPLC), where 1 PLC for 60 Hz is
16.67 ms (1/60) and 1 PLC for 50 Hz is 20 ms (1/50).
Example
smua.measure.nplc = 0.5 Sets the integration time for SMU channel A to 0.5/60
seconds.
Also see
reset() (on page 7-155)
setup.recall() (on page 7-175)
smuX.measure.adc (on page 7-193)
smuX.reset() (on page 7-211)
Speed (on page 2-78)