Keithley 2657A, Справочное руководство, Страница: 151 / 805

Model 2657A High Power System SourceMeter® Instrument Reference Manual Section 3: Functions and features
2657A-901-01 Rev. B/December 2012 3-37
The source-measure unit (SMU) can be configured to perform any or all available measurements
during a sweep using the
smua.trigger.measure.
Y
()
function. To enable the measure action for
a simple synchronous sweep, set the
smua.trigger.measure.action
attribute to
smua.ENABLE
. To enable the measure action for an asynchronous sweep, set the
smua.trigger.measure.action
attribute to
smua.ASYNC
.
In asynchronous mode, trigger your measurements before the source completes the sweep (before
the end sweep action occurs).
Configured source and measure delays are imposed when the SMU executes the source and
measure action blocks. Additionally, if the measure count setting is greater than one, then the
measure count is satisfied each time the measure action is performed. Refer to
Sweep operation (on
page 3-19) for information about configuring source and measure sweeps.
The arm and trigger counts must be set to control how many times the SMU executes the source and
measure actions. The arm count indicates the number of times to execute the complete sweep. The
trigger count sets the number of loops in the trigger layer. Typically, you set the trigger count to be
equal to the number of points in the configured sweep. If the trigger count is not equal to the number
of points configured in the sweep, then one of the following occurs:
•
If the trigger count is greater than the number of points in a sweep as configured by
smua.trigger.source.linear
Y
()
,
smua.trigger.source.log
Y
()
, or
smua.trigger.source.list
Y
()
, then the SMU will satisfy the trigger count by restarting the
sweep values from the beginning.
•
If the trigger count is less than the number of source values configured, then the SMU will satisfy
the trigger count and ignore the remaining source values.
For example, configure a three-point linear voltage sweep from 100 to 300 V, with the trigger count
set to 2. The SMU will output 100 V, 200V. If the trigger count is set to 6, then the SMU will output the
values 100 V, 200 V, 300 V, 100 V, 200 V, 300 V, repeating the source values twice in a single
sweep.
Enabling pulse mode sweeps using the end pulse action
Enable pulse mode sweeps using the end pulse action. The example command below illustrates how
to configure pulse mode sweeps by setting the end pulse action:
smua.trigger.endpulse.action = smua.SOURCE_IDLE
Timers can be used to configure the pulse width and period (see Timers (on page 3-42) for more
information). To disable pulse mode sweeps, set the
smua.trigger.endpulse.action
attribute
to
smua.SOURCE_HOLD
.
NOTE