Keithley 4200A-SCS Reference Manual page 947

Section 13: LPT library function reference
Pulsers
4225-PMU
Pulse mode
Standard and Segment Arb
Details
When using pulse_fetch to retrieve data, you need to pause the program to allow time for the
buffer to fill. You can use the sleep command to pause for a specified period of time, or you can use
the pulse_exec_status command in a while loop to wait until the test is completed.
Use this command to retrieve a block of newly generated test data in pseudo real-time and
temporarily store it in the data buffer. The stored data can then be analyzed and manipulated as
needed before posting it to the Clarius Analyze sheet.
Typically, this command is used with the pulse_exec_status command to allow the test to finish
before retrieving the data.
The block of data to be retrieved is set by the StartIndex and StopIndex parameters. The start
index parameter specifies the first index number in the buffer, and the stop index parameter specifies
the final index number. For example, assume there are 1000 data test points for a test, and you want
to retrieve the first 50 data points. The start index value is set to zero (0) and the stop index is set to
49.
The Vmeas, Imeas, Timestamp, and Status parameters are array names defined by the user. If
you do not want to retrieve the time stamp or status, NULL can be passed as valid parameters for
these fields.
The return of all readings must be enabled by the pulse_meas_sm command. If disabled, the arrays
will not be retrieved.
For spot mean measurements, data can be mixed; the amplitude and base level readings are
returned in the same array buffer area and must be separated (or parsed) after the measurement
cycle is complete. See the pulse_meas_sm command for details on spot mean measurements. Note
that number of measurements returned is determined by the spot means enabled in
pulse_meas_sm. With both amplitude and base measurements enabled, there will be two voltage
and two current readings for each pulse (with spot mean discrete) or each pulse burst (with spot
mean average). Voltage and current readings are returned in individual arrays: Vmeas, Imeas. When
both amplitude and base readings are enabled, the readings are alternated. For example, the Vmeas
array: Vampl_1, Vbase_1, Vampl_2, Vbase_2, Vampl_3, Vbase_3, and so on. To plot the amplitude
values, separate the amplitude and base measurements into individual arrays before using
PostDataDouble to post the measurements to the sheet.
The time stamps pertain to either per spot mean reading or per sample. Status is returned as a 32-bit
word. The status code bit map is shown in the following table.
If you do not need to analyze or manipulate the test data before posting it to the Clarius Analyze
sheet, you can use the pulse_measrt command. The pulse_measrt command retrieves all the
test data in pseudo real-time and automatically posts it into the Clarius Analyze sheet.
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Model 4200A-SCS Parameter Analyzer Reference Manual
4200A-901-01 Rev. C / February 2017