Technical data

Measure Commands 25
Agilent Infiniium 9000 Series Oscilloscopes Programmer's Reference 491
When any of the defined measurements are requested, the oscilloscope
first determines the top (100%) and base (0%) voltages of the waveform.
From this information, the oscilloscope determines the other important
voltage values (10%, 90%, and 50% voltage values) for making
measurements.
The 10% and 90% voltage values are used in the rise time and fall time
measurements when standard thresholds are selected. The 50% voltage
value is used for measuring frequency, period, pulse width, and duty cycle
with standard thresholds selected.
You can also make measurements using user- defined thresholds instead of
the standard thresholds.
When the command form of a measurement is used, the oscilloscope is
placed in the continuous measurement mode. The measurement result will
be displayed on the front panel. There may be a maximum of 5
measurements running continuously. Use the SCRatch command to turn
off the measurements.
When the query form of the measurement is used, the measurement is
made one time, and the measurement result is returned.
• If the current acquisition is complete, the current acquisition is
measured and the result is returned.
• If the current acquisition is incomplete and the oscilloscope is running,
acquisitions will continue to occur until the acquisition is complete. The
acquisition will then be measured and the result returned.
• If the current acquisition is incomplete and the oscilloscope is stopped,
the measurement result will be 9.99999e+37 and the incomplete result
state will be returned if SENDvalid is ON.
All measurements are made using the entire display, except for VAVerage
and VRMS which allow measurements on a single cycle. Therefore, if you
want to make measurements on a particular cycle, display only that cycle
on the screen.
Measurements are made on the displayed waveforms specified by the
SOURce command. The SOURce command lets you specify two sources.
Most measurements are only made on a single source. Some
measurements, such as the DELTatime measurement, require two sources.
If the waveform is clipped, the measurement result may be questionable.
In this case, the value returned is the most accurate value that can be
made using the current scaling. You might be able to obtain a more
accurate measurement by adjusting the vertical scale to prevent the
waveform from being clipped.