Section 6: Characterization of power discretes
Model 2651A High Power System SourceMeter® Instrument User's Manual
9. The trigger model checks the current Trigger Layer iteration number against the trigger count.
•
If the iteration number is less than the trigger count, the trigger model stays in the trigger layer and
wraps around to the Source Event, where it waits again for an event trigger from TSP-Link Trigger 1.
The trigger model repeats from step 2.
•
If the iteration number is greater than the trigger count, the SMU trigger model exits the Trigger Layer
and goes into the Arm Layer.
10. Because the arm count is set to 1, the trigger model exits the Arm Layer and returns to an idle
state.
Example program code
NOTE
The example code is designed to be run from Test Script Builder or TSB Embedded. It can also be
run from other programming environments, such as Microsoft
®
Visual Studio
®
or National Instruments
LabVIEW
TM
. However, modification of the example code may be required to do so.
The following is a Test Script Processor (TSP
®
) script that performs a series of sweeps to collect I-V
curve data for power MOSFETs and IGBT devices. The script contains all the code necessary to:
•
Initialize the TSP-Link
®
connection
•
Configure the output and trigger models of the source-measure unit (SMU), as described in the
previous section
•
Prepare the reading buffers
•
Execute the test
•
Return the collected data in a format that can be copied from the instrument console and pasted
into Microsoft
®
Excel
®
The script is written using Test Script Processor (TSP
®
) functions rather than as a single block of
inline code. TSP functions are similar to functions in other programming languages, such as
Microsoft
®
Visual C
®
or Visual Basic
®
, and must be called before the code contained in them is
executed. Because of this, running the script alone will not execute the test. To execute the test, run
the script to load the functions into test script memory and then call the functions. Refer to the
documentation for Test Script Builder or TSB Embedded for directions on how to run scripts and enter
commands using the instrument console.
The script contains comments that describe what is being performed by the lines of code and
documents the functions in the script.
Lines starting with
node[2].
are commands that are being sent to the Series 26xxA through the
TSP-Link interface. All other commands are executed on the Model 2651A.
6-10
2651A-900-01 Rev. A / March 2011
