Tektronix Keithley SourceMeter 2450 - Page 71

Section
7: Measuring I-V characteristics of FETs Model 2450 SourceMeter® Instrument
User's Manual
7-8 2450-900-01 Rev. E / August 2019
SMU 1,
SMU 2, or
pseudocode
Commands Description
Pseudocode
for i = 0, 5, 0.1 do:
 Set up a for loop from 0 to 5 in 0.1
steps (inclusive).
SMU 2
:SOUR:VOLT i
:SOUR:CONF:LIST:STORE "sweepVals"
 Set the voltage level to the iteration
number.
 Store the source configuration to
sweepVals
.
Pseudocode
end for
 End the
for
loop.
SMU 2
:
TRIG:BLOC:CONF:RECALL 1, "sweepVals"
:TRIG:BLOC:SOUR:STAT 2, ON
:TRIG:BLOC:WAIT 3, DIG1
:TRIG:BLOC:DEL:CONS 4, 0.01
:TRIG:BLOC:MDIG 5
:TRIG:BLOC:CONF:NEXT 6, "sweepVals"
:TRIG:BLOC:BRAN:COUN 7, 51, 4
:TRIG:BLOC:NOT 8, 2
:TRIG:BLOC:BRAN:COUN 9, 4, 3
:TRIG:BLOC:SOUR:STAT 10, OFF
 Create a block to load sweepVals
at the first index.
 Create a block to turn the output on.
 Create a block to wait on digital line
3.
 Create a block to delay for 0.01
seconds.
 Create a block to make a
measurement.
 Create a block to load the next
index of sweepVals.
 Create a block to branch to block 4,
50 times.
 Create a block to generate the
notify2 event.
 Create a block to branch to block 3,
three times.
 Create a block to turn the output off.
SMU 1 :INIT
*WAI
 Initiate the trigger model.
 Wait for the model to complete.
SMU 2
:INIT
*WAI
 Initiate the trigger model.
 Wait for the model to complete.
Pseudocode
vds = []
ids = []
for i = 2, 5 do:
 Create an empty array to hold
measured voltage values.
 Create an empty array to hold
measured current values.
 Set up a for loop from 2 to 5
(including 5).
Pseudocode
for SMU2
vds[i-1] = TRAC:DATA? 1 +
51*(i-2), 51*(i-1),
"defbuffer1", SOUR
ids[i-1] = TRAC:DATA? 1 +
51*(i-2), 51*(i-1),
"defbuffer1", READ
 Save the sourced and measured
values to the arrays vds and ids,
respectively. The readings from
each step are saved at each index
in the array.
Pseudocode
end for
 End the
for
loop.