Tektronix Keithley 2651A Reference Manual page 142

Section 3: Functions and features Model 2651A High Power System SourceMeter® Instrument Reference Manual
The sweep can be either positive-going or negative-going, depending on the relative values of the
start and stop parameters. When the sweep starts, the output goes to the start source level. The
output then changes in equal steps until the stop level is reached. If the trigger count is greater than
the number of points specified, the SMU starts over at the beginning value.
To configure a linear staircase sweep, use the smua.trigger.source.linearY() command.
This function configures the source values the SMU outputs when performing a linear sweep. After
configuring the sweep, you must also enable the source action by setting the following attribute:
smua.trigger.source.action
Example:
-- Configure a sweep from 0 to 10 V in 1 V steps.
smua.trigger.source.linearv(0, 10, 11)
-- Enable the source action.
smua.trigger.source.action = smua.ENABLE
For more information, see smuX.trigger.source.linearY() (on page 7-302).
Logarithmic staircase sweeps
This type of sweep is similar to the linear staircase sweep. The steps, however, are done on a
logarithmic scale.
Like a linear staircase sweep, logarithmic sweeps are configured using a start level, a stop level, and
the number of points. The step size is determined by the start and stop levels, and the number of
sweep points. However, in a logarithmic sweep, the step size increases or decreases exponentially.
To create an increasing logarithmic sweep, set the stop value to be greater than the start value. To
create a decreasing logarithmic sweep, set the stop value to be less than the start value. When
enabled, a measurement is made at each step after source and measurement settling time. An
asymptote can also be used to control the inflection of a sweep.
The number of sweep steps actually performed is determined by the trigger count. See Triggering
(on page 3-36) for more information.
3-24 2651A-901-01 Rev. C October 2021