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2600AS-901-01 Rev. B / September 2008
Section 19: Remote Commands
Series 2600A System SourceMeter® Instruments Reference Manual
smuX.trigger.source.logY
X = SMU channel (a or b)
Y = SMU measure function (
i
or
v
)
Where:
v
= voltage,
i
= current
Function
Configures an exponential (geometric) source sweep.
TSP-Link
accessibility
This function can be accessed from a remote TSP-Link node.
Usage
smuX.trigger.source.logi(startvalue, endvalue, points, asymptote)
smuX.trigger.source.logv(startvalue, endvalue, points, asymptote)
startvalue
Source value of the first point.
endvalue
Source value of the last point.
points
Used to calculate the step sizes during the sweep.
asymptote
The asymptotic offset value.
Remarks
• This function configures a geometric source sweep.
• During the sweep, the source will generate a geometric series of ascending or descending
voltage or current changes called steps. Each step is larger or smaller than the previous step by
a fixed proportion. The constant of proportionality is determined by the starting value, the ending
value, the asymptote, and the number of steps in the sweep. The number of source steps is one
less than the number of sourced data points.
• The
points
parameter does not set the number of steps in a sweep. It is only used to calculate
source values within a subsequent sweep. If the subsequent sweep has more points than
specified here, the source will restart at the beginning. If the subsequent sweep has less points
than specified here,
endvalue
will not be reached during the sweep.
• In cases where the first sweep point is non-zero, it may be necessary to pre-charge the circuit so
that the sweep will return a stable value for the first measured point without penalizing remaining
points in the sweep.
• With logarithmic sweeps it is usually necessary to allow the source to auto range to maintain
good source accuracy when sweeping over more than one decade or across range boundaries.
• The
asymptote
parameter can be used to customize the inflection and/or offset of the source
value curve. This allows log sweeps to cross zero. Setting this parameter to zero provides a
conventional logarithmic sweep. The
asymptote
value is the value that the curve would have at
either positive or negative infinity depending on the direction of the sweep.
• The
asymptote
value must not be equal to or between the starting and ending values. It must
be outside the range defined by the starting and ending values.
• The SMU will only store the most recent configured source action. The last call to
smuX.trigger.source.linearY
,
smuX.trigger.source.listY
, or
smuX.trigger.source.logY
is used for the source action.
Also see
smuX.trigger.source.set
X = SMU channel (a or b)
Function
Sets the source event detector to the detected state.
TSP-Link
accessibility
This function can be accessed from a remote TSP-Link node.
Usage
smuX.trigger.source.set()
Remarks
• This function sets the source event detector to the detected state.
• The SMU will automatically clear all event detectors when the
smuX.trigger.initiate
function is executed. This function should be called after the sweep is initiated.
Also see
