Keithley 4200-SCS Reference Manual page 143

Model 4200-SCS Reference Manual
2.
4200-901-01 Rev. S / May 2017
With real time plotting:
#include "keithley.h"
int IV(double startv, double stopv, int numpoint,
double * V, int Vsize, double * I, int Isize)
{
int index;
double stepv;
// error checking
if ((numpoint != Vsize) ||(numpoint != Isize))
return –1;
//calculate stepv
if (numpoint != 1)
stepv = (stopv – startv)/(numpoint –1);
// measurement loop
for (index = 0; index < numpoint; index ++)
{
// calculate voltage array
V[index] = startv + stepv*index;
forcev(SMU1, V[index]); // force voltage
intgi(SMU1,&I[index]); // measure current
// transfer V data
PostDataDouble("V", V[index]);
// transfer I data
PostDataDouble("I", I[index]);
}
return (OK);
}
Taking measurements using external instruments
The same idea applies to measurements using external instruments. A trigger (sweep) data
method cannot be used because real time plotting requires real time data. In the above
method, the data will not be ready until the sweep is done. The following is an example of
getting real time data from external instruments.
Test sequence without real time plotting:
initialize instrument;
setup sweep;
setup trigger; trigger measurement;
serial poll the instrument until measurement is done;
retrieve data from instrument;
post measurement clean up;
done;
Test sequence with real time plotting:
initialize instrument;
setup single point measurement mode;
setup single trigger mode;
turn on output; calculate number
of data point;
// measurement loop
for (index = 0; index < numpoint; index ++)
{
setup force value in each step;
take measurement;
// transfer data for real time plotting
PostDataDouble("Variable Name", MeasureArray[index]);
}
post measurement clean up;
done;
Return to
Section 6: Keithley Interactive Test Environment (KITE)
Section Topics 6-17