Keithley 6430 Instruction Manual page 391

Logarithmic current sweep
Logarithmic current sweep from 1mA to 100mA in 20 points:
*RST
SOUR:FUNC:MODE CURR
SOUR:SWE:SPAC LOG
SOUR:CURR:STAR .001
SOUR:CURR:STOP .1
SOUR:SWE:POIN 20
TRIG:COUN 20
SOUR:CURR:MODE SWE
OUTP ON
INIT
To determine the source values that will be generated:
Start: 0.001 Log
Stop: 0.1 Log
LogStep = (Log (Stop) - Log
10
= (-1 - (-3) / (20 - 1)
= 2/ 19
= 0.105263
Now add the LogStep value to Log
list of Log Values. Next take the anti-log of each Log
10
Value# Log Value
10
1 -3.000000
2 -2.894737
3 -2.789474
4 -2.684211
5 -2.578948
6 -2.473685
7 -2.368422
8 -2.263159
9 -2.157896
10 -2.052633
11 -1.947370
12 -1.842107
13 -1.736844
14 -1.631581
15 -1.526318
16 -1.421055
17 -1.315792
18 -1.210526
19 -1.105263
20 -1.000000
(Start): -3
10
(Stop): -1
10
(Start)) / (SWE:POIN -1)
10
(Start) and to each subsequent result. This will create a
10
Sweep Value
0.001000
0.001274
0.001623
0.002069
0.002637
0.003360
0.004281
0.005456
0.006952
0.008859
0.011288
0.014384
0.018329
0.023357
0.029763
0.037927
0.048329
0.061584
0.078475
0.100000
SCPI Command Reference
Value to get the actual sweep values:
10
17-81