Keysight Technologies RP7900 Series, Operating And Service Manual

Page: 146 / 318

The AC line frequency is detected automatically for the SENSe:SWEep:NPLC
command.
Measurement Windowing
Windowing is a signal conditioning process that reduces the error in average measurements made in
the presence of periodic signals and noise. Two window functions are available: Rectangular and
Hanning. At power-on, the measurement window is Rectangular.
The Rectangular window calculates average measurements without any signal conditioning.
However, in the presence of periodic signals such AC line ripple, a Rectangular window can introduce
errors when calculating average measurements. This can occur when a non-integral number of cycles
of data has been acquired due to the last partial cycle of acquired data.
One way of dealing with AC line ripple is to use a Hanning window. The Hanning window applies a cos4
weighting function to the data when calculating average measurements. This attenuates the AC noise
in the measurement window. The best attenuation is achieved when at least three or more waveform
cycles are in the measurement.
Front Panel Menu Reference SCPI Command
Select Measure\Window .
Select either Rectangular or Hanning.
Then press Select .
To set the sense window to Hanning:
SENS:WIND HANN
A-hour & W-hour measurement
Amp-hour and watt-hour measurements are available on all RPS models. These measurements are
made independently of other measurements.
The amp-hour and watt-hour measurements are created by accumulating full range current and
power measurements at approximately 200k samples/second. The accumulators can hold enough
data for at least 100,000 hours.
The approximate limit of accumulated charge is ±(900,000,000•IRATING) in Coulombs or ±
(250,000•IRATING) in Amp-hours.
The approximate limit of accumulated energy is ±(1,100,000,000•PRATING) in Joules or ±
(310,000•PRATING) in Watt-hours.
IRATING is the current rating of the unit. PRATING is the power rating of the unit.
To return Amp-hours and Watt-hours measurements:
Front Panel Menu Reference SCPI Command
Select Measure\AHWH .
Displays the accumulated Amp-hours and Watt-hours.
To return the Amp-hours and Watt hours:
FETC:AHO?
FETC:WHO?
4 Using the Regenerative Power System
146 Keysight RP7900 Series Operating and Service Guide