Keithley Interactive SourceMeter 2450 - TSP Commands for Solar Cell Characterization

Section
9: Measuring I-V characteristics of solar cells Model 2450 Interactive SourceMeter® Instrument
User's Manual
9-8 2450-900-01 Rev. C / December 2013
Send the following commands for this example application:
--Define the number of points in the sweep.
num = 56
--Reset the instrument and clear the buffer.
reset()
--Set the source and measure functions.
smu.measure.func = smu.FUNC_DC_CURRENT
smu.source.func = smu.FUNC_DC_VOLTAGE
--Measurement settings.
smu.measure.terminals = smu.TERMINALS_FRONT
smu.measure.sense = smu.SENSE_4WIRE
smu.measure.autorange = smu.ON
smu.measure.nplc = 1
--Source settings.
smu.source.highc = smu.OFF
smu.source.range = 2
smu.source.readback = smu.ON
smu.source.ilimit.level = 1
smu.source.sweeplinear("SolarCell", 0, 0.53, num, 0.1)
--Start the trigger model and wait for it to complete.
trigger.model.initiate()
waitcomplete()
--Define initial values.
voltage = defbuffer1.sourcevalues
current = defbuffer1
isc = current[1]
mincurr = current[1]
imax = current[1]
voc = voltage[1]
vmax = voltage[1]
pmax = voltage[1]*current[1]
--Calculate values.
for i = 1, num do
print(voltage[i],current[i],voltage[i]*current[i])
if (voltage[i]*current[i] < pmax) then
pmax = voltage[i]*current[i]
imax = current[i]
vmax = voltage[i]
end
if math.abs(current[i]) < math.abs(mincurr) then
voc = voltage[i]
end
end
pmax = math.abs(pmax)
imax = math.abs(imax)
print("Pmax = ", pmax, ", Imax = ", imax, ", Vmax = ", vmax, ", Isc = ", isc, ",
Voc = ", voc)
--Display values on the front panel.
display.changescreen(display.SCREEN_USER_SWIPE)
display.settext(display.TEXT1, string.format("Pmax = %.4fW", pmax))
display.settext(display.TEXT2, string.format("Isc = %.4fA, Voc = %.2fV", isc, voc))