Model 2651A High Power System SourceMeter® Instrument User's Manual   Section 7: Increasing SMU current sourcing ability 
When the trigger model of Model 2651A (subordinate, node[2]) is initialized, the following occurs: 
1.  The source-measure unit (SMU) trigger model leaves the idle state, flows through the arm layer, 
enters the trigger layer, and reaches the Source Event, where it waits for an event trigger. 
2.  TSP-Link trigger 1 receives a trigger from the TSP-Link interface and outputs an event trigger to 
the SMU Source Event. 
3.  The SMU Source Event Detector receives the event trigger from TSP-Link trigger 1, begins to 
output the pulse, waits the programmed source delay (if any), and outputs the 
SOURCE_COMPLETE event to timer 1 before allowing the SMU trigger model to continue. 
 
4.  Timer 1 receives the SOURCE_COMPLETE event trigger from TSP-Link trigger 1 and begins its 
countdown. 
5.  The SMU trigger model continues to the Measure Event, where it waits for a programmed 
measure delay (if any), takes a measurement, and then continues until it stops at the End Pulse 
Event, where it waits for an event trigger. 
6.  The timer 1 countdown expires and timer 1 outputs an event trigger to the SMU End Pulse Event. 
 
7.  The SMU's End Pulse Event Detector receives the event trigger from timer 1, outputs the falling 
edge of the pulse, and then allows the SMU trigger model to continue. 
8.  The SMU trigger model compares the current trigger layer loop iteration with the trigger count. 
•  If the current iteration is less than the trigger count, the trigger layer repeats and the SMU trigger model 
reaches Source Event, where it waits for another trigger from TSP-Link trigger 1. The trigger model then 
repeats from step 2. 
•  If the current iteration is equal to the trigger count, the SMU trigger model exits the trigger layer, passes 
through the arm layer, and returns to an idle state. 
 
Series 2600A trigger model operation 
In this example, the Series 2600A is controlled by script, so its trigger model is not used. 
 
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. 
 
2651A-900-01 Rev. A / March 2011  7-9