Tektronix Keithley 2601B-PULSE Reference Manual

Section 5: Reading buffers Model 2601B-PULSE System SourceMeter Instrument Reference Manual
5-10 2601B-PULSE-901-01A April 2020
Statistic attributes
Use the smua.buffer.getstats() function to access the reading buffer data statistics. The table
below displays the attributes that you can use to access the reading buffer statistics.
The returned parameter has the attributes described in the following table.
Attributes for accessing reading buffer data
Attribute
When returned
Description
n
Always
The number of data points on which the statistics are based.
mean
When n > 0
The average of all readings added to the buffer.
stddev
When n > 1
The standard deviation of all readings added to the buffer.
min
When n > 0
A table that contains data about the minimum reading value added to the buffer.
max
When n > 0
A table that contains data about the maximum reading value added to the buffer.
If n equals zero (0), all other attributes is nil because there is no data to base any statistics on. If n
equals 1, the stddev attribute is nil because the standard deviation of a sample size of 1
is undefined.
The min and max entries have the attributes described in the following table. bufferVar is the name
of the buffer. See smua.buffer.getstats() (on page 11-177) for additional information.
Min and max entry attributes
Attribute
Description
measurefunction
String indicating the function measured for the reading (current, voltage,
ohms, or watts).
measurerange
The full-scale range value for the measure range used when the
measurement was made.
reading
The reading value.
sourcefunction
String indicating the source function at the time of the measurement
(current or voltage).
sourceoutputstate
String indicating the state of the source (off or on).
sourcerange
Full-scale range value for the source range used when the measurement
was made.
sourcevalue
If bufferVar.collectsourcevalues is enabled, the sourced value in
effect at the time of the reading.
status
Status value for the reading; the status value is a floating-point number that
encodes the status value into a floating-point value.
timestamp
If bufferVar.collecttimestamps is enabled, the timestamp, in
seconds, between when the reading was acquired and when the first
reading in the buffer was acquired; adding this value to the base timestamp
gives the actual time when the measurement was acquired.
Example:
The following programming example illustrates how to output mean and standard deviation statistics
from buffer 1:
statistics = smua.buffer.getstats(smua.nvbuffer1)
print(statistics.mean, statistics.stddev)

Tektronix Keithley 2601B-PULSE Specifications

General

Brand	Tektronix
Model	Keithley 2601B-PULSE
Category	Measuring Instruments
Language	English