2606B System SourceMeter® Instrument Reference Manual
Section 3: Functions and features
2606B-901-01 Rev. B / May 2018
3-37
Clearing SMU event detectors
When an event detector is cleared, the event detector discards previously detected trigger events.
This prevents the source-measure unit (SMU) from using trigger events that were detected during the
last sweep or while it is in the arm layer, and allows it to start monitoring for new trigger events.
SMU event detectors are automatically cleared when:
•
A sweep is initiated using the
smu
X
.trigger.initiate()
function*.
•
The SMU moves from the arm layer into the trigger layer and the
smu
X
.trigger.autoclear
attribute is enabled.
* smu
X
can be
smua
for SMU Channel A or
smub
for SMU Channel B
Using the TRIG key to trigger a sweep
The source-measure unit (SMU) can be configured to perform a sweep where each source step is
triggered by the virtual front-panel TRIG key. The source action is preceded by the source event
detector. The SMU pauses operation at an event detector until a programmed event occurs. The
SMU can be programmed to wait at the source event detector (that is, not start the source action)
until the TRIG key is pressed.
To configure the virtual front panel TRIG key to trigger the source action, assign the trigger event
created by the TRIG key (
display.trigger.EVENT_ID
) to the source stimulus input
(smu
X
.trigger.source.stimulus
).
The programming example below illustrates how to configure a 10-point linear voltage sweep on SMU
A, where each step is triggered by the TRIG key:
-- Configure a 10-point source voltage sweep.
smua.trigger.source.linearv(1, 10, 10)
smua.trigger.source.action = smua.ENABLE
-- Configure TRIG key press as input trigger for source action.
smua.trigger.source.stimulus = display.trigger.EVENT_ID
-- Command SMU to execute a single 10-point sweep.
smua.trigger.count = 10
smua.trigger.arm.count = 1
-- Turn on the output in preparation for the sweep
smua.source.output = smua.OUTPUT_ON
-- Start the sweep and clear the event detectors.
smua.trigger.initiate()
-- The SMU will wait for the virtual front panel TRIG key press before executing
-- each source action.
-- Wait for the sweep to complete.
waitcomplete()
The following figure graphically illustrates this example. See
(on page 3-19) for
more information about sweep operation.