Keithley 2657A - Sweepvlogmeasurei()

Section 7: TSP command reference Model 2657A High Power System SourceMeter® Instrument Reference Manual
7-328 2657A-901-01 Rev. B/December 2012
Example
myvlist = {-100, 100, -200, 200, -400,
400, -800, 800, -1600, 1600}
SweepVListMeasureI(smua, myvlist,
500E-3, 10)
This function performs a 10-point voltage list sweep
starting at the first point in myvlist. Current is
measured at every step (point) in the sweep. The
source will be allowed to settle on each step for
500 ms before a measurement is performed.
Also see
KISweep factory script (on page 5-19)
SweepVLogMeasureI()
This KISweep factory script function performs a logarithmic voltage sweep with current measured at every step
(point).
Type TSP-Link accessible
Affected by Where saved Default value
Function No
Usage
SweepVLogMeasureI(smu, startv, stopv, stime, points)
smu
System SourceMeter
®
instrument channel (set to smua)
startv
Sweep start voltage in volts
stopv
Sweep stop voltage in volts
stime
Settling time in seconds; occurs after stepping the source and before performing a
measurement
points
Number of sweep points (must be ≥2)
Details
Data for current measurements, voltage source values, and timestamps are stored in smuX.nvbuffer1.
If all parameters are omitted when this function is called, this function is executed with the parameters set to the
default values.
Performs a logarithmic voltage sweep with current measured at every step (point):
1. Sets the smu to output startv amperes, allows the source to settle for stime seconds, and then
performs a current measurement.
2. Sets the smu to output the next volts step, allows the source to settle for stime seconds, and then
performs a current measurement.
3. Repeats the above sequence until the voltage is measured on the stopv volts step.
The source level at each step (SourceStepLevel) is automatically calculated as follows:
MeasurePoint = The step point number for a measurement
For example, for a five-point sweep (points = 5), a measurement is performed at MeasurePoint 1, 2, 3, 4,
and 5.
LogStepSize = (log10(stopi) – log10(starti)) / (points – 1)
LogStep = (MeasurePoint – 1) * (LogStepSize)
SourceStepLevel = antilog(LogStep) * startv