Waveform Average Readings; Measurement Timing - Keithley 4200A-SCS User Manual

Model 4200A-SCS Pulse Card (PGU and PMU) User's Manual

Waveform average readings

For this data acquisition type, each returned reading is a mean average of the corresponding samples
for all the pulses in the burst. For example, in the figure in
the V and I readings for sample 1 - pulse 1 would be averaged with the V and I readings for
sample 1 - pulse 2.
The figure below shows how waveform average readings are returned as a data set for two pulse
periods with voltage, current, and time stamp readings enabled.

Measurement timing

Use the pulse_meas_timing function to configure pulse measurement timing.
Spot mean measurement timing
The spot mean measurement type samples a portion of the amplitude and a portion of the base level.
The measured samples are then averaged to yield a single voltage and current reading for the
amplitude and base low levels. The NumPulses (number of pulses) parameter specifies the number
of pulses to be output and sampled.
The figure below shows that three measured samples are taken on the amplitude and six samples are
taken on the base level. The start and stop percentage values indicate the portions of the pulse that
are sampled. As shown, the beginning of the amplitude and base level are designated as the zero (0)
percent points; the ends are designated as the 100% points. The start and stop points for amplitude
and base-level sampling are expressed as a percentage between 0% and 100%. The default is 75%
for the start of spot mean and 90% for end of spot mean. These percentages are applied to the total
time of the pulse top. In this example, sampling for the amplitude and base levels starts at 60% (0.6)
and ends at 80% (0.8).
4200A-PMU-900-01 Rev. A December 2020
Figure 98: Returned data set for waveform average readings
Section 4: Pulse card concepts
Waveform discrete readings (on page 4-26),
4-27